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Hi all, I'm fairly new to Java and my overall coding skills are not as advanced as I'd like them to be but I really would appreciate it if someone could help me with this problem.
My first goal is to code an application for Android which measures the acceleration (X, Y, Z directions) and displays the values in a TextView.
There will be other user configurable options like unit conversion or limits with audio warnings etc. later on.
Right now I only have a few lines of code and the application already force closes right after starting.
I am posting my MainActivity.java, my activity_main.xml and the sensoractivity2 Manifest. Please point me in the right direction!
MainActivity.java:
Code:
package com.example.sensoractivity2;
import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.TextView;
public class MainActivity extends Activity implements SensorEventListener{
private SensorManager sensorManager;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sensorManager=(SensorManager) getSystemService(SENSOR_SERVICE);
sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL);
}
public void onSensorChanged(SensorEvent event) {
float x, y, z = 0;
if (event.sensor.getType()==Sensor.TYPE_ACCELEROMETER) {
x=event.values[0];
y=event.values[1];
z=event.values[2];
TextView tx = (TextView) findViewById(R.id.textView1);
tx.setText((int) x);
TextView ty = (TextView) findViewById(R.id.textView2);
ty.setText((int) y);
TextView tz = (TextView) findViewById(R.id.textView3);
tz.setText((int) z);
}
}
[user=439709]@override[/user]
public void onAccuracyChanged(Sensor arg0, int arg1) {
// TODO Auto-generated method stub
}
}
activity_main.xml
Code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="X-Wert" />
<TextView
android:id="@+id/textView2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Y-Wert" />
<TextView
android:id="@+id/textView3"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Z-Wert" />
</LinearLayout>
sensoractivity2 Manifest:
Code:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.sensoractivity2"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk
android:minSdkVersion="8"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme">
<activity android:name="com.example.sensoractivity2.MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
</manifest>
First thing I see is that you are not setting your view in your activity classes "oncreate" method. Can you post your logcat output when the app force closes? That will help the most.
Could you please post a logcat?
Just the lines of your app. Get it using the logcat view in Eclipse.
Look at the bold for changes that will help you. When you are working with view objects, you shouldn't create the object in a listener or something that is called over and over. You will be creating a memory leak.
Code:
package com.example.sensoractivity2;
import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.TextView;
public class MainActivity extends Activity implements SensorEventListener{
private SensorManager sensorManager;
[B]TextView tx = null;
TextView ty = null;
TextView tz = null;[/B]
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sensorManager=(SensorManager) getSystemService(SENSOR_SERVICE);
[B] setContentView(R.layout.activity_main);[/B]
sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL);
[B]tx = (TextView) findViewById(R.id.textView1);
ty = (TextView) findViewById(R.id.textView2);
tz = (TextView) findViewById(R.id.textView3);[/B]
}
public void onSensorChanged(SensorEvent event) {
float x, y, z = 0;
if (event.sensor.getType()==Sensor.TYPE_ACCELEROMETER) {
x=event.values[0];
y=event.values[1];
z=event.values[2];
[B]tx.setText((int) x);
ty.setText((int) y);
tz.setText((int) z);[/B]
}
}
[user=439709]@override[/user]
public void onAccuracyChanged(Sensor arg0, int arg1) {
// TODO Auto-generated method stub
}
}
Here is the part of the catlog which I believe to be relevant when the crash occurs:
Code:
04-28 18:34:24.628: E/SurfaceFlinger(36): ro.sf.lcd_density must be defined as a build property
04-28 18:34:25.750: E/Trace(1735): error opening trace file: No such file or directory (2)
04-28 18:34:27.452: I/ARMAssembler(36): generated scanline__00000077:03515104_00009002_00000000 [127 ipp] (149 ins) at [0x40f081f0:0x40f08444] in 34521256 ns
04-28 18:34:29.430: I/Choreographer(1153): Skipped 388 frames! The application may be doing too much work on its main thread.
04-28 18:34:29.462: I/ARMAssembler(36): generated scanline__00000077:03010104_00008002_00000000 [ 89 ipp] (110 ins) at [0x40f08450:0x40f08608] in 17654283 ns
04-28 18:34:30.825: W/ActivityManager(1003): Launch timeout has expired, giving up wake lock!
04-28 18:34:31.673: D/AndroidRuntime(1735): Shutting down VM
04-28 18:34:31.673: W/dalvikvm(1735): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
04-28 18:34:31.737: E/AndroidRuntime(1735): FATAL EXCEPTION: main
04-28 18:34:31.737: E/AndroidRuntime(1735): java.lang.NullPointerException
04-28 18:34:31.737: E/AndroidRuntime(1735): at com.example.sensoractivity2.MainActivity.onSensorChanged(MainActivity.java:27)
04-28 18:34:31.737: E/AndroidRuntime(1735): at android.hardware.SystemSensorManager$ListenerDelegate$1.handleMessage(SystemSensorManager.java:204)
04-28 18:34:31.737: E/AndroidRuntime(1735): at android.os.Handler.dispatchMessage(Handler.java:99)
04-28 18:34:31.737: E/AndroidRuntime(1735): at android.os.Looper.loop(Looper.java:137)
04-28 18:34:31.737: E/AndroidRuntime(1735): at android.app.ActivityThread.main(ActivityThread.java:5041)
04-28 18:34:31.737: E/AndroidRuntime(1735): at java.lang.reflect.Method.invokeNative(Native Method)
04-28 18:34:31.737: E/AndroidRuntime(1735): at java.lang.reflect.Method.invoke(Method.java:511)
04-28 18:34:31.737: E/AndroidRuntime(1735): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-28 18:34:31.737: E/AndroidRuntime(1735): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-28 18:34:31.737: E/AndroidRuntime(1735): at dalvik.system.NativeStart.main(Native Method)
04-28 18:34:31.813: W/ActivityManager(1003): Force finishing activity com.example.sensoractivity2/.MainActivity
04-28 18:34:31.893: W/WindowManager(1003): Failure taking screenshot for (328x583) to layer 21010
04-28 18:34:32.643: D/dalvikvm(1003): GC_FOR_ALLOC freed 588K, 26% free 7082K/9496K, paused 471ms, total 481ms
Thanks for your hints, zalez! Going to try that now.
The logcat states a nullpointer error. I believe my corrections will fix at least that error.
spelaben said:
Here is the part of the catlog which I believe to be relevant when the crash occurs:
Code:
04-28 18:34:24.628: E/SurfaceFlinger(36): ro.sf.lcd_density must be defined as a build property
04-28 18:34:25.750: E/Trace(1735): error opening trace file: No such file or directory (2)
04-28 18:34:27.452: I/ARMAssembler(36): generated scanline__00000077:03515104_00009002_00000000 [127 ipp] (149 ins) at [0x40f081f0:0x40f08444] in 34521256 ns
04-28 18:34:29.430: I/Choreographer(1153): Skipped 388 frames! The application may be doing too much work on its main thread.
04-28 18:34:29.462: I/ARMAssembler(36): generated scanline__00000077:03010104_00008002_00000000 [ 89 ipp] (110 ins) at [0x40f08450:0x40f08608] in 17654283 ns
04-28 18:34:30.825: W/ActivityManager(1003): Launch timeout has expired, giving up wake lock!
04-28 18:34:31.673: D/AndroidRuntime(1735): Shutting down VM
04-28 18:34:31.673: W/dalvikvm(1735): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
04-28 18:34:31.737: E/AndroidRuntime(1735): FATAL EXCEPTION: main
04-28 18:34:31.737: E/AndroidRuntime(1735): java.lang.NullPointerException
04-28 18:34:31.737: E/AndroidRuntime(1735): at com.example.sensoractivity2.MainActivity.onSensorChanged(MainActivity.java:27)
04-28 18:34:31.737: E/AndroidRuntime(1735): at android.hardware.SystemSensorManager$ListenerDelegate$1.handleMessage(SystemSensorManager.java:204)
04-28 18:34:31.737: E/AndroidRuntime(1735): at android.os.Handler.dispatchMessage(Handler.java:99)
04-28 18:34:31.737: E/AndroidRuntime(1735): at android.os.Looper.loop(Looper.java:137)
04-28 18:34:31.737: E/AndroidRuntime(1735): at android.app.ActivityThread.main(ActivityThread.java:5041)
04-28 18:34:31.737: E/AndroidRuntime(1735): at java.lang.reflect.Method.invokeNative(Native Method)
04-28 18:34:31.737: E/AndroidRuntime(1735): at java.lang.reflect.Method.invoke(Method.java:511)
04-28 18:34:31.737: E/AndroidRuntime(1735): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-28 18:34:31.737: E/AndroidRuntime(1735): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-28 18:34:31.737: E/AndroidRuntime(1735): at dalvik.system.NativeStart.main(Native Method)
04-28 18:34:31.813: W/ActivityManager(1003): Force finishing activity com.example.sensoractivity2/.MainActivity
04-28 18:34:31.893: W/WindowManager(1003): Failure taking screenshot for (328x583) to layer 21010
04-28 18:34:32.643: D/dalvikvm(1003): GC_FOR_ALLOC freed 588K, 26% free 7082K/9496K, paused 471ms, total 481ms
Thanks for your hints, zalez! Going to try that now.
Click to expand...
Click to collapse
zalez said:
The logcat states a nullpointer error. I believe my corrections will fix at least that error.
Click to expand...
Click to collapse
True, nullpointer errors are fixed. After debugging it again, I'm getting these errors now:
Code:
04-28 19:07:59.466: E/AndroidRuntime(858): FATAL EXCEPTION: main
04-28 19:07:59.466: E/AndroidRuntime(858): android.content.res.Resources$NotFoundException: String resource ID #0x0
04-28 19:07:59.466: E/AndroidRuntime(858): at android.content.res.Resources.getText(Resources.java:230)
04-28 19:07:59.466: E/AndroidRuntime(858): at android.widget.TextView.setText(TextView.java:3769)
04-28 19:07:59.466: E/AndroidRuntime(858): at com.example.sensoractivity2.MainActivity.onSensorChanged(MainActivity.java:33)
04-28 19:07:59.466: E/AndroidRuntime(858): at android.hardware.SystemSensorManager$ListenerDelegate$1.handleMessage(SystemSensorManager.java:204)
04-28 19:07:59.466: E/AndroidRuntime(858): at android.os.Handler.dispatchMessage(Handler.java:99)
04-28 19:07:59.466: E/AndroidRuntime(858): at android.os.Looper.loop(Looper.java:137)
04-28 19:07:59.466: E/AndroidRuntime(858): at android.app.ActivityThread.main(ActivityThread.java:5041)
04-28 19:07:59.466: E/AndroidRuntime(858): at java.lang.reflect.Method.invokeNative(Native Method)
04-28 19:07:59.466: E/AndroidRuntime(858): at java.lang.reflect.Method.invoke(Method.java:511)
04-28 19:07:59.466: E/AndroidRuntime(858): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-28 19:07:59.466: E/AndroidRuntime(858): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-28 19:07:59.466: E/AndroidRuntime(858): at dalvik.system.NativeStart.main(Native Method)
Any ideas?
spelaben said:
True, nullpointer errors are fixed. After debugging it again, I'm getting these errors now:
Code:
04-28 19:07:59.466: E/AndroidRuntime(858): FATAL EXCEPTION: main
04-28 19:07:59.466: E/AndroidRuntime(858): android.content.res.Resources$NotFoundException: String resource ID #0x0
04-28 19:07:59.466: E/AndroidRuntime(858): at android.content.res.Resources.getText(Resources.java:230)
04-28 19:07:59.466: E/AndroidRuntime(858): at android.widget.TextView.setText(TextView.java:3769)
04-28 19:07:59.466: E/AndroidRuntime(858): at com.example.sensoractivity2.MainActivity.onSensorChanged(MainActivity.java:33)
04-28 19:07:59.466: E/AndroidRuntime(858): at android.hardware.SystemSensorManager$ListenerDelegate$1.handleMessage(SystemSensorManager.java:204)
04-28 19:07:59.466: E/AndroidRuntime(858): at android.os.Handler.dispatchMessage(Handler.java:99)
04-28 19:07:59.466: E/AndroidRuntime(858): at android.os.Looper.loop(Looper.java:137)
04-28 19:07:59.466: E/AndroidRuntime(858): at android.app.ActivityThread.main(ActivityThread.java:5041)
04-28 19:07:59.466: E/AndroidRuntime(858): at java.lang.reflect.Method.invokeNative(Native Method)
04-28 19:07:59.466: E/AndroidRuntime(858): at java.lang.reflect.Method.invoke(Method.java:511)
04-28 19:07:59.466: E/AndroidRuntime(858): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-28 19:07:59.466: E/AndroidRuntime(858): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-28 19:07:59.466: E/AndroidRuntime(858): at dalvik.system.NativeStart.main(Native Method)
Any ideas?
Click to expand...
Click to collapse
It needs to be
Code:
tx.setText(String.valueOf(x));
ty.setText(String.valueOf(y));
tz.setText(String.valueOf(z));
If you pass an int, the TextView thinks that it is a resource id. That is why you need to convert it to a String first.
I over looked the bold part. When setting text for a Textview, it has to be in string format. There is no implied conversion.
Code:
package com.example.sensoractivity2;
import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.TextView;
public class MainActivity extends Activity implements SensorEventListener{
private SensorManager sensorManager;
TextView tx = null;
TextView ty = null;
TextView tz = null;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sensorManager=(SensorManager) getSystemService(SENSOR_SERVICE);
setContentView(R.layout.activity_main);
sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL);
tx = (TextView) findViewById(R.id.textView1);
ty = (TextView) findViewById(R.id.textView2);
tz = (TextView) findViewById(R.id.textView3);
}
public void onSensorChanged(SensorEvent event) {
float x, y, z = 0;
if (event.sensor.getType()==Sensor.TYPE_ACCELEROMETER) {
x=event.values[0];
y=event.values[1];
z=event.values[2];
tx.setText[B](Integer.toString(x)[/B]);
ty.setText([B]Integer.toString(y)[/B]);
tz.setText([B]Integer.toString(z)[/B]);
}
}
[user=439709]@override[/user]
public void onAccuracyChanged(Sensor arg0, int arg1) {
// TODO Auto-generated method stub
}
}
nikwen said:
It needs to be
Code:
tx.setText(String.valueOf(x));
ty.setText(String.valueOf(y));
tz.setText(String.valueOf(z));
If you pass an int, the TextView thinks that it is a resource id. That is why you need to convert it to a String first.
Click to expand...
Click to collapse
Yes! That did the trick! Now my next problem is that I only see one value instead of three, from there on I will try to move on by myself.
Sorry, I'm not sure if this is relevant, but you aren't overriding your onCreate method? Could that have anything to do with it?
MaartenXDA said:
Sorry, I'm not sure if this is relevant, but you aren't overriding your onCreate method? Could that have anything to do with it?
Click to expand...
Click to collapse
He does:
public void onCreate(Bundle savedInstanceState) {
Click to expand...
Click to collapse
He just did not wrote the @override annotation before that. As far as i know, you do not have to use it.
EDIT: Yep, it does not matter. See this: http://stackoverflow.com/questions/94361/when-do-you-use-javas-override-annotation-and-why
It says that it is just for ensuring that you are overriding the right method and for making the code easier to read.
Hi all, I am a bit further with my project since I found some time to work on it again.
//edit, force closes on starting fixed!
Here is what it is supposed to be doing: It reads the x, y and z values for acceleration from the LINEAR_ACCELERATION sensor. If a certain value is exceeded a timer will be started. If the amount of seconds the timer counts is higher than a defined threshold, it will play the default notifcation sound.
If the value from the sensor is below the threshold, it will stop the timer. The whole timer thing isn't working, the notification is played as soon as the normal acceleration threshold is passed and the time is ignored.
Please review my code below and tell me what I'm not seeing here, note that I'm still a noob.
Also I'm interested in a method to capture the maximum values read from the sensor and put it in a textview, can you help me?
AccelMeter.java:
Code:
package com.example.accelmeter;
import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.media.Ringtone;
import android.media.RingtoneManager;
import android.net.Uri;
import android.os.Bundle;
import android.os.SystemClock;
import android.view.View;
import android.widget.Button;
import android.widget.Chronometer;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class AccelMeter extends Activity implements SensorEventListener {
private SensorManager sensorManager;
// Objekte deklarieren
TextView xC;
TextView yC;
TextView zC;
Chronometer chrono;
/* accThreshold = Schwellenwert in m/s² für die Beschleunigung
* accInterval = Zeitraum in Sekunden, über den der Wert für die Beschleunigung überwacht wird
*/
private float accThreshold = 50;
private float accInterval = 0;
[user=439709]@override[/user]
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_accel_meter);
// Achsen Objekte erstellen
xC=(TextView)findViewById(R.id.xCoordinate);
yC=(TextView)findViewById(R.id.yCoordinate);
zC=(TextView)findViewById(R.id.zCoordinate);
/* Sensor.TYPE_LINEAR_ACCELERATION = Beschleunigung auf jeder Achse ohne Gravitation in m/s²
* SENSOR_DELAY_FASTEST = schnellster Modus für Messung. Alternativen z.B. _GAME, _NORMAL oder _UI
*/
sensorManager=(SensorManager)getSystemService(SENSOR_SERVICE);
sensorManager.registerListener(this,
sensorManager.getDefaultSensor(Sensor.TYPE_LINEAR_ACCELERATION),
SensorManager.SENSOR_DELAY_NORMAL);
// Schwellenwert festlegen und mit einer Toast-Benachrichtigung bestätigen, Fehlerbehandlung wenn kein Wert eingegeben wurde
Button setThreshold = (Button)findViewById(R.id.setThreshold);
setThreshold.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
try {
EditText et = (EditText)findViewById(R.id.threshold);
accThreshold = Float.valueOf(et.getText().toString());
Toast.makeText(getApplicationContext(), "Neuer Schwellenwert festgelegt!", Toast.LENGTH_SHORT).show();
}
catch (Exception e) {
Toast.makeText(getApplicationContext(), "Es wurde noch kein Wert eingegeben!", Toast.LENGTH_SHORT).show();
}
}
});
// Intervall festlegen und mit einer Toast-Benachrichtigung bestätigen, Fehlerbehandlung wenn kein Wert eingegeben wurde
Button setInterval = (Button)findViewById(R.id.setInterval);
setInterval.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
try {
EditText et = (EditText)findViewById(R.id.editInterval);
accInterval = Float.valueOf(et.getText().toString());
Toast.makeText(getApplicationContext(), "Neues Intervall festgelegt!", Toast.LENGTH_SHORT).show();
}
catch (Exception e) {
Toast.makeText(getApplicationContext(), "Es wurde noch kein Wert eingegeben!", Toast.LENGTH_SHORT).show();
}
}
});
// Programm beenden
Button exit = (Button)findViewById(R.id.exit);
exit.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
finish();
System.exit(0);
}
});
}
public void onSensorChanged(SensorEvent event){
// Sensor Typ überprüfen
if(event.sensor.getType()==Sensor.TYPE_LINEAR_ACCELERATION){
// Richtungen verknüpfen
float x=event.values[0];
float y=event.values[1];
float z=event.values[2];
// Gerundete Ergebnisse mit vier Nachkommastellen ausgeben
xC.setText("X: "+(Math.abs(Math.round(x * 1000) / 1000.0)));
yC.setText("Y: "+(Math.abs(Math.round(y * 1000) / 1000.0)));
zC.setText("Z: "+(Math.abs(Math.round(z * 1000) / 1000.0)));
// Wenn Beschleunigung über Schwellenwert liegt, starte Timer. Wenn Timer das festgelete Intervall überschreitet, spiele Benachrichtigungston
if (x + y + z > accThreshold)
{
chrono = new Chronometer(this);
chrono.setBase(SystemClock.elapsedRealtime());
chrono.start();
long seconds = ((chrono.getBase()-SystemClock.elapsedRealtime()/1000%60));
if (seconds >= accInterval)
{
Uri notification = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
Ringtone r = RingtoneManager.getRingtone(getApplicationContext(), notification);
r.play();
}
else
{
chrono.stop();
}
}
}
}
[user=439709]@override[/user]
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// TODO Auto-generated method stub
}
}
activity_accel_meter.xml:
Code:
<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<TableRow tools:ignore="ExtraText" >
<TextView
android:id="@+id/xCoordinate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="X Koordinate: "
android:textAppearance="?android:attr/textAppearanceLarge"
tools:ignore="HardcodedText" />
/>
</TableRow>
<TableRow>
<TextView
android:id="@+id/yCoordinate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Y Koordinate: "
android:textAppearance="?android:attr/textAppearanceLarge"
tools:ignore="HardcodedText" />
/>
</TableRow>
<TableRow>
<TextView
android:id="@+id/zCoordinate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Z Koordinate: "
android:textAppearance="?android:attr/textAppearanceLarge"
tools:ignore="HardcodedText" />
/>
</TableRow>
<EditText
android:id="@+id/threshold"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Schwellenwert (float)"
android:inputType="numberDecimal"
tools:ignore="HardcodedText" />
<Button
android:id="@+id/setThreshold"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Schwellenwert festlegen"
tools:ignore="HardcodedText" />
<EditText
android:id="@+id/editInterval"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Zeit in Sekunden"
android:inputType="number"
tools:ignore="HardcodedText" >
<requestFocus />
</EditText>
<Button
android:id="@+id/setInterval"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Zeitraum für Überwachung festlegen"
tools:ignore="HardcodedText" />
<Button
android:id="@+id/exit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Beenden"
tools:ignore="HardcodedText" />
</TableLayout>
Yay German code (live there, too) xD Initialise your seconds in your onCreate, it's much nicer and probably the problem. A method gets the highest value the sensor measured would be a simple
Code:
double savedVal=0; //or any other type
private void updateMaxVal(){
double currentVal =// get the value from the specific sensor
if(savedVal<currentVal) {
savedVal = currentVal;
// maybe save the time as well
}
You'd have to put that method in the onsensorchanged so it will be called often. Then update your text View with the new saved value
SimplicityApks said:
Yay German code (live there, too) xD Initialise your seconds in your onCreate, it's much nicer and probably the problem. A method gets the highest value the sensor measured would be a simple
Code:
double savedVal=0; //or any other type
private void updateMaxVal(){
double currentVal =// get the value from the specific sensor
if(savedVal<currentVal) {
savedVal = currentVal;
// maybe save the time as well
}
You'd have to put that method in the onsensorchanged so it will be called often. Then update your text View with the new saved value
Click to expand...
Click to collapse
Hey fellow German!
If I initialise the seconds variable in the onCreate part it says that the variable is not being used (yellow marking) and in the code below I get an error obviously stating that the variable is unknown. ^^
I have three different values, how can I link the x, y and z variables in the method and how can I make sure the variables are known inside of the method? (Same problem as above)
Since I don't know how to do it with a method I just wrote the following code in my onsensorchanged part, the problem is that the max value textviews always show the same as the current value textviews:
float savedValX = 0;
float savedValY = 0;
float savedValZ = 0;
float currentValX = event.values[0];
float currentValY = event.values[1];
float currentValZ = event.values[2];
if (savedValX < currentValX) {
savedValX = currentValX;
xM.setText("X max: "+(Math.abs(Math.round(currentValX * 1000) / 1000.0)));
}
if (savedValY < currentValY) {
savedValY = currentValY;
yM.setText("Y max: "+(Math.abs(Math.round(currentValY * 1000) / 1000.0)));
}
if (savedValZ < currentValZ) {
savedValZ = currentValZ;
zM.setText("Z max: "+(Math.abs(Math.round(currentValZ * 1000) / 1000.0)));
}
Also I still have the problem that my seconds interval is being ignored.
//edit, fixed it! Now I only need the max value method.
OK so I now understand what you are trying to do with your Chronometer, the problem is that you reinitialize it every time the onSensorChanged is called so if you then ask for the seconds it has just started. To fix this, you could set an onChronometerTickListener and set your textViews in that method. To avoid recreating the Chrono use
Code:
if(chrono==null){
chrono = new Chronometer();
chrono.start();
}
If u don't want the tick listener or it doesn't work ( haven't used it yet) you can put your if(seconds<...)in the else {}of above method. But remember that the onSensorChanged is called EVERYTIME the sensor registers a change, this might be very often or just sometimes, so there is no guarantee that the text views will be updated if the else clause in that method is used
PS forget about the initializing of the seconds, I don't know what I was thinking yesterday, but I guess it was too late ...
/*edit:
What I meant with
Code:
double savedVal=0; //or any other type
private void updateMaxVal(){
is that you save your value in your class ("globally"), so that it is accessible to the whole class.
and to do it nicely you can do it like this:
Code:
float savedValX = 0;
float savedValY = 0;
float savedValZ = 0;
boolean change = false;
private void updateMaxVals(SensorEvent event){ // call this method in your onSensorChanged
change = false;
savedValX = getMax(event.values[0], savedValX);
if(change){
xM.setText("X max: "+(Math.abs(Math.round(savedValX * 1000) / 1000.0)));
}
savedValY = getMax(event.values[1], savedValY);
if(change){
yM.setText("Y max: "+(Math.abs(Math.round(savedValY * 1000) / 1000.0)));
}
savedValZ = getMax(event.values[2], savedValZ);
if(change){
yM.setText("Z max: "+(Math.abs(Math.round(savedValZ * 1000) / 1000.0)));
}
}
private float getMax(float currentVal, float savedVal){
if(currentVal > savedVal){
change = true;
return currentVal;
}else{
change = false;
return savedVal;
}
}
Im trying to start a simple app and i need to display on a SurfaceView the preview of the cam as soon as the App start.
i added the permission to the manifest:
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
and my code:
Code:
import android.content.Context;
import android.hardware.Camera;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class MainActivity extends SurfaceView implements SurfaceHolder.Callback{
SurfaceView mSurfaceView;
private SurfaceHolder mHolder;
public Camera camera = null;
public MainActivity(Context context) {
super(context);
mSurfaceView = (SurfaceView) findViewById(R.id.surfaceView);
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
[user=439709]@override[/user]
public void surfaceCreated(SurfaceHolder holder) {
camera = Camera.open();
try{
camera.setPreviewDisplay(mHolder);
} catch(Exception e){
}
}
[user=439709]@override[/user]
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Camera.Parameters params = camera.getParameters();
params.setPreviewSize(width,height);
camera.setParameters(params);
camera.startPreview();
}
[user=439709]@override[/user]
public void surfaceDestroyed(SurfaceHolder holder) {
camera.stopPreview();
camera = null;
}
}
Ive looked for many tutorial and all technically do the same or smiliart stuff. But the app crashes. I cant find a solution
LogCat
Code:
06-01 12:39:12.456 616-841/system_process I/ActivityManager: START u0 {act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.droidcam/.MainActivity bnds=[240,408][240,408]} from pid 861
06-01 12:39:12.596 616-841/system_process D/dalvikvm: GC_FOR_ALLOC freed 1352K, 16% free 11518K/13560K, paused 112ms, total 118ms
06-01 12:39:12.636 2744-2744/? D/dalvikvm: Late-enabling CheckJNI
06-01 12:39:12.646 616-881/system_process I/ActivityManager: Start proc com.example.droidcam for activity com.example.droidcam/.MainActivity: pid=2744 uid=10019 gids={50019, 1006, 1028}
06-01 12:39:12.746 2744-2744/com.example.droidcam E/Trace: error opening trace file: No such file or directory (2)
06-01 12:39:12.826 2744-2744/com.example.droidcam D/dalvikvm: newInstance failed: no <init>()
06-01 12:39:12.836 2744-2744/com.example.droidcam D/AndroidRuntime: Shutting down VM
06-01 12:39:12.836 2744-2744/com.example.droidcam W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x2b5d9930)
06-01 12:39:12.836 2744-2744/com.example.droidcam E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.droidcam/com.example.droidcam.MainActivity}: java.lang.InstantiationException: can't instantiate class com.example.droidcam.MainActivity; no empty constructor
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2223)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2357)
at android.app.ActivityThread.access$600(ActivityThread.java:153)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1247)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5226)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.InstantiationException: can't instantiate class com.example.droidcam.MainActivity; no empty constructor
at java.lang.Class.newInstanceImpl(Native Method)
at java.lang.Class.newInstance(Class.java:1319)
at android.app.Instrumentation.newActivity(Instrumentation.java:1054)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2214)
... 11 more
06-01 12:39:12.836 616-1341/system_process W/ActivityManager: Force finishing activity com.example.droidcam/.MainActivity
06-01 12:39:12.986 616-650/system_process D/dalvikvm: GC_FOR_ALLOC freed 1696K, 24% free 10472K/13772K, paused 76ms, total 77ms
06-01 12:39:13.387 616-647/system_process W/ActivityManager: Activity pause timeout for ActivityRecord{2bd8aff0 u0 com.example.droidcam/.MainActivity}
06-01 12:39:18.952 2744-2744/? I/Process: Sending signal. PID: 2744 SIG: 9
06-01 12:39:18.952 616-943/system_process I/ActivityManager: Process com.example.droidcam (pid 2744) has died.
06-01 12:39:19.002 616-616/system_process W/InputMethodManagerService: Window already focused, ignoring focus gain of: [email protected] attribute=null, token = [email protected]
Please put your code into code tags.
EDIT: Thanks.
and Post/check logcats.
just saying it crashes is too vague.
out of ideas said:
and Post/check logcats.
just saying it crashes is too vague.
Click to expand...
Click to collapse
On Eclipse i know how to show the windows of the LogCat, but cant really find it here on Android Studio.
Im a bit newby about this sorry, coming from PHP using just Notepad.
Guess i found it, added log cat
I saw some tutorial like this, im not sure why it doesnt start.
Is it for te onCreate method missing? but i saw that for other works anyway like this
Btw i've also triyed an other way, but stills give me errors. i could upload that one too, different logcat.
Hope one of the two could be solved
Code:
import android.app.Activity;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import java.io.IOException;
public class MainActivity extends Activity implements SurfaceHolder.Callback{
/* VARIABILI PRIVATE */
private SurfaceView mSurfaceView;
private SurfaceHolder mSurfaceHolder;
private Camera mCamera;
/** Called when the activity is first created. */
[user=439709]@override[/user]
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSurfaceView = (SurfaceView)findViewById(R.id.surfaceView);
mSurfaceHolder = mSurfaceView.getHolder();
mSurfaceHolder.addCallback(this);
mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
[user=439709]@override[/user]
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
Camera.Parameters params = mCamera.getParameters();
params.setPreviewSize(arg2, arg3);
mCamera.setParameters(params);
try {
//lancio la preview
mCamera.setPreviewDisplay(arg0);
mCamera.startPreview();
} catch (IOException e) {
//gestione errore
}
}
[user=439709]@override[/user]
public void surfaceCreated(SurfaceHolder holder) {
mCamera = Camera.open();
}
[user=439709]@override[/user]
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mCamera.release();
}
logcat
Code:
06-01 13:32:31.187 616-661/system_process I/ActivityManager: Start proc com.android.vending for service com.android.vending/com.google.android.finsky.services.ContentSyncService: pid=25552 uid=10005 gids={50005, 3003, 1015, 1028}
06-01 13:32:31.227 25552-25552/com.android.vending E/Trace: error opening trace file: No such file or directory (2)
06-01 13:32:31.387 616-841/system_process I/ActivityManager: START u0 {act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.droidcam/.MainActivity bnds=[240,408][240,408]} from pid 861
06-01 13:32:31.437 25566-25566/? D/dalvikvm: Late-enabling CheckJNI
06-01 13:32:31.447 616-1341/system_process I/ActivityManager: Start proc com.example.droidcam for activity com.example.droidcam/.MainActivity: pid=25566 uid=10019 gids={50019, 1006, 1028}
06-01 13:32:31.607 25566-25566/com.example.droidcam E/Trace: error opening trace file: No such file or directory (2)
06-01 13:32:31.787 25552-25552/com.android.vending D/Finsky: [1] FinskyApp.onCreate: Initializing network with DFE https://android.clients.google.com/fdfe/
06-01 13:32:31.987 25552-25552/com.android.vending D/Finsky: [1] DailyHygiene.goMakeHygieneIfDirty: No need to run daily hygiene.
06-01 13:32:32.037 25552-25552/com.android.vending W/Settings: Setting download_manager_max_bytes_over_mobile has moved from android.provider.Settings.Secure to android.provider.Settings.Global.
06-01 13:32:32.037 25552-25552/com.android.vending W/Settings: Setting download_manager_recommended_max_bytes_over_mobile has moved from android.provider.Settings.Secure to android.provider.Settings.Global.
06-01 13:32:32.178 616-881/system_process D/dalvikvm: GC_FOR_ALLOC freed 656K, 26% free 11321K/15124K, paused 82ms, total 86ms
06-01 13:32:32.238 25566-25566/com.example.droidcam D/libEGL: loaded /system/lib/egl/libEGL_adreno200.so
06-01 13:32:32.258 25566-25566/com.example.droidcam D/libEGL: loaded /system/lib/egl/libGLESv1_CM_adreno200.so
06-01 13:32:32.258 25566-25566/com.example.droidcam D/libEGL: loaded /system/lib/egl/libGLESv2_adreno200.so
06-01 13:32:32.268 25566-25566/com.example.droidcam I/Adreno200-EGL: <qeglDrvAPI_eglInitialize:294>: EGL 1.4 QUALCOMM build: AU_LINUX_ANDROID_JB.04.01.01.00.036_msm8960_JB_CL2644550_release_AU (CL2644550)
Build Date: 07/31/12 Tue
Local Branch:
Remote Branch: quic/master
Local Patches: NONE
Reconstruct Branch: AU_LINUX_ANDROID_JB.04.01.01.00.036 + NOTHING
06-01 13:32:32.318 25566-25566/com.example.droidcam D/OpenGLRenderer: Enabling debug mode 0
06-01 13:32:32.348 256-515/? I/AwesomePlayer: setDataSource_l(URL suppressed)
06-01 13:32:32.378 256-25622/? D/MediaExtractor: returning default extractor
06-01 13:32:32.388 256-515/? I/AwesomePlayer: setDataSource_l(URL suppressed)
06-01 13:32:32.408 256-25626/? D/MediaExtractor: returning default extractor
06-01 13:32:32.408 256-515/? I/CameraClient: Opening camera 0
06-01 13:32:32.408 256-515/? W/ServiceManager: Permission failure: com.sonyericsson.permission.CAMERA_EXTENDED from uid=10019 pid=25566
06-01 13:32:32.438 256-25630/? I/caladbolg: 3348999538 cald_camctrl.c (6713) 25630 P [SVR] -945967758 + Cald_CamCtrl_PowerUp
06-01 13:32:32.438 256-25630/? I/caladbolg: 3348999630 cald_camctrl.c (7484) 25630 P [SVR] -945967666 + Cald_CamCtrl_FSM_Func_PowerUp
06-01 13:32:32.438 256-25630/? I/caladbolg: 3349003170 cald_hal_qct.c (2789) 25630 P [HAL] -945964126 + Cald_Hal_Qct_If_PowerUp
06-01 13:32:32.438 256-25630/? I/caladbolg: 3349003323 cald_hal_qct.c (2847) 25630 P [HAL] -945963973 - Cald_Hal_Qct_If_PowerUp (0)
06-01 13:32:32.438 256-25630/? I/caladbolg: 3349004665 cald_camctrl.c (7563) 25630 P [SVR] -945962631 - Cald_CamCtrl_FSM_Func_PowerUp (0)
06-01 13:32:32.438 256-25630/? I/caladbolg: 3349004726 cald_camctrl.c (6720) 25630 P [SVR] -945962570 - Cald_CamCtrl_PowerUp (0)
06-01 13:32:32.448 256-25630/? E/caladbolg: 3349014431 cald_camctrl.c (11888) 25630 E [SVR] PreviewSize Invalid param: value[402x527]
06-01 13:32:32.458 25566-25566/com.example.droidcam D/AndroidRuntime: Shutting down VM
06-01 13:32:32.458 25566-25566/com.example.droidcam W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x2b5d9930)
06-01 13:32:32.488 25566-25566/com.example.droidcam E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.RuntimeException: setParameters failed
at android.hardware.Camera.native_setParameters(Native Method)
at android.hardware.Camera.setParameters(Camera.java:1496)
at com.example.droidcam.MainActivity.surfaceChanged(MainActivity.java:41)
at android.view.SurfaceView.updateWindow(SurfaceView.java:580)
at android.view.SurfaceView.access$000(SurfaceView.java:86)
at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:174)
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:680)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1842)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
at android.view.Choreographer.doCallbacks(Choreographer.java:562)
at android.view.Choreographer.doFrame(Choreographer.java:532)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5226)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
at dalvik.system.NativeStart.main(Native Method)
06-01 13:32:32.498 616-943/system_process W/ActivityManager: Force finishing activity com.example.droidcam/.MainActivity
06-01 13:32:32.688 25552-25552/com.android.vending D/Finsky: [1] 2.run: Loaded library for account: [i1YaFxIWaZrcOQ26zxNX5K0RvvY]
06-01 13:32:32.688 25552-25552/com.android.vending D/Finsky: [1] 2.run: Finished loading 1 libraries.
06-01 13:32:32.908 25552-25552/com.android.vending D/Finsky: [1] 5.onFinished: Installation state replication succeeded.
06-01 13:32:33.018 616-647/system_process W/ActivityManager: Activity pause timeout for ActivityRecord{2b946870 u0 com.example.droidcam/.MainActivity}
In Android you normally do not use the constructor of an Activity for anything.
Use the onCreate method instead.
EDIT: The log says that the constructor must be empty.
nikwen said:
In Android you normally do not use the constructor of an Activity for anything.
Use the onCreate method instead.
EDIT: The log says that the constructor must be empty.
Click to expand...
Click to collapse
I thought about that (even if i saw video tutorial doing it) so i tried wht onCreate method and now it seams to give problem with the setParameters?
Ive uploaded the new code and logcats before
Ah. Check this: http://stackoverflow.com/questions/3890381/camera-setparameters-failed-in-android
nikwen said:
Ah. Check this: http://stackoverflow.com/questions/3890381/camera-setparameters-failed-in-android
Click to expand...
Click to collapse
i tryed that at th beggin, and didnt work, in fact i tried it again and still give me the same error apparently
While I'm still learning myself, it looks like you are getting a failed camera permission. And then it tries to pass in an invalid parameter to the camera.
deniel said:
I/CameraClient: Opening camera 0
06-01 13:32:32.408 256-515/? W/ServiceManager: Permission failure: com.sonyericsson.permission.CAMERA_EXTENDED from uid=10019 pid=25566
06-01 13:32:32.448 256-25630/? E/caladbolg: 3349014431 cald_camctrl.c (11888) 25630 E [SVR] PreviewSize Invalid param: value[402x527]
[/CODE]
Click to expand...
Click to collapse
Sent from a Toasted Devil
netwokz said:
While I'm still learning myself, it looks like you are getting a failed camera permission. And then it tries to pass in an invalid parameter to the camera.
Sent from a Toasted Devil
Click to expand...
Click to collapse
But cant understand which one and how should i do. it ryed the 2 ways everybody does
What phone are you trying this on? Have you tried it in an emulator?
After getting home and I was able to try your second piece of code. It looks like it is a problem with <CODE>params.setPreviewSize(arg2, arg3);</CODE>, it doesn't like the width and height arguments. I found THIS(second answer). and after plugging it into your code it was working for me. If you like I can show you the modified code, altho its real easy to plug in.
netwokz said:
After getting home and I was able to try your second piece of code. It looks like it is a problem with <CODE>params.setPreviewSize(arg2, arg3);</CODE>, it doesn't like the width and height arguments. I found THIS(second answer). and after plugging it into your code it was working for me. If you like I can show you the modified code, altho its real easy to plug in.
Click to expand...
Click to collapse
i tryed his first example and finally i get his "distoted" image. When i'll have time ill try the rets thnk u very much
ill try this:
Code:
Camera.Size getBestPreviewSize(int width, int height, Camera.Parameters parameters) {
Camera.Size result=null;
float dr = Float.MAX_VALUE;
float ratio = (float)width/(float)height;
for (Camera.Size size : parameters.getSupportedPreviewSizes()) {
float r = (float)size.width/(float)size.height;
if( Math.abs(r - ratio) < dr && size.width <= width && size.height <= height ) {
dr = Math.abs(r - ratio);
result = size;
}
}
return result;
}
Code:
ublic void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// Now that the size is known, set up the camera parameters and begin
// the preview.
if (isPreviewRunning) {
mCamera.stopPreview();
}
Camera.Parameters parameters = mCamera.getParameters();
List<Size> sizes = parameters.getSupportedPreviewSizes();
Size optimalSize = getBestPreviewSize( w, h, parameters);
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
mCamera.setParameters(parameters);
mCamera.startPreview();
isPreviewRunning =true;
}
im not sure abot the 3rd parameter of the getBestPreviewSize method which one is it. Like this is still distorted
Yeah, I could never fix the distortion back when I was trying my camera app. But I think I will tinker with it again. Keep this updated if you find anything, I will also.
Sent from a Toasted Devil
I'm creating a new FragmentPreference and then I want add a OnClickListener to an Preference:
My PreferenceFragment-Class:
Code:
public class PreferencesFragment extends PreferenceFragment {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.settings);
}
}
And my FragmentActivity:
Code:
public class SettingsActivity extends PreferenceActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
PreferencesFragment frag = new PreferencesFragment();
getFragmentManager().beginTransaction().replace(android.R.id.content, frag).commit();
Preference deleteLocalDataPref = frag.findPreference("deleteLocalData");
deleteLocalDataPref.setOnPreferenceClickListener(Pref_OnClickhandler);
}
OnPreferenceClickListener Pref_OnClickhandler = new OnPreferenceClickListener() {
@Override
public boolean onPreferenceClick(Preference arg0) {
new DeleteSettings().execute();
return false;
}
};
}
And the error:
02-10 08:06:10.598: E/AndroidRuntime(1836): FATAL EXCEPTION: main
02-10 08:06:10.598: E/AndroidRuntime(1836): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test/com.test.SettingsActivity}: java.lang.NullPointerException
02-10 08:06:10.598: E/AndroidRuntime(1836): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
02-10 08:06:10.598: E/AndroidRuntime(1836): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
02-10 08:06:10.598: E/AndroidRuntime(1836): at android.app.ActivityThread.access$600(ActivityThread.java:141)
02-10 08:06:10.598: E/AndroidRuntime(1836): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
02-10 08:06:10.598: E/AndroidRuntime(1836): at android.os.Handler.dispatchMessage(Handler.java:99)
02-10 08:06:10.598: E/AndroidRuntime(1836): at android.os.Looper.loop(Looper.java:137)
02-10 08:06:10.598: E/AndroidRuntime(1836): at android.app.ActivityThread.main(ActivityThread.java:5039)
02-10 08:06:10.598: E/AndroidRuntime(1836): at java.lang.reflect.Method.invokeNative(Native Method)
02-10 08:06:10.598: E/AndroidRuntime(1836): at java.lang.reflect.Method.invoke(Method.java:511)
02-10 08:06:10.598: E/AndroidRuntime(1836): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
02-10 08:06:10.598: E/AndroidRuntime(1836): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
02-10 08:06:10.598: E/AndroidRuntime(1836): at dalvik.system.NativeStart.main(Native Method)
02-10 08:06:10.598: E/AndroidRuntime(1836): Caused by: java.lang.NullPointerException
02-10 08:06:10.598: E/AndroidRuntime(1836): at com.test.SettingsActivity.onCreate(SettingsActivity.java:44)
02-10 08:06:10.598: E/AndroidRuntime(1836): at android.app.Activity.performCreate(Activity.java:5104)
02-10 08:06:10.598: E/AndroidRuntime(1836): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
02-10 08:06:10.598: E/AndroidRuntime(1836): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
02-10 08:06:10.598: E/AndroidRuntime(1836): ... 11 more
Click to expand...
Click to collapse
Why I get a NullPointerException? The Preference does exist...
Code:
<Preference
android:key="deleteLocalData"
android:summary="@string/pref_delete_local_data_summary"
android:title="@string/pref_delete_local_data" />
What happens when you comment the line you think is offending? And which line are you commenting?
Please give a thanks if you think this post helped you!
Sent from my Nexus 4 using XDA Premium 4 Mobile App .
When I comment the lines
Code:
Preference deleteLocalDataPref = frag.findPreference("deleteLocalData");
deleteLocalDataPref.setOnPreferenceClickListener(Pref_OnClickhandler);
my preferences are shown correctly.
OK, I changed some parts. This is what works for me:
Code:
import android.app.Activity;
import android.os.Bundle;
import android.preference.Preference;
import android.preference.PreferenceFragment;
public class SettingsActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.settings);
PreferenceFragment preferenceFragment = (PreferenceFragment) getFragmentManager().findFragmentById(R.id.pref_frag_id);
Preference deleteLocalDataPref = preferenceFragment.findPreference("deleteLocalData");
deleteLocalDataPref.setOnPreferenceClickListener(Pref_OnClickhandler);
}
Preference.OnPreferenceClickListener Pref_OnClickhandler = new Preference.OnPreferenceClickListener() {
@Override
public boolean onPreferenceClick(Preference arg0) {
new DeleteSettings().execute();
return false;
}
};
}
/res/layout/settings.xml:
Code:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<fragment
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:name="com.example.app.PreferencesFragment"
android:id="@+id/pref_frag_id"/>
</FrameLayout>
(Replace the package name.)
/res/xml/settings.xml:
Code:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<Preference
android:key="deleteLocalData"
android:summary="@string/pref_delete_local_data_summary"
android:title="@string/pref_delete_local_data" />
</PreferenceScreen>
I changed the way the Fragment is added. If you need to do it dynamically, have a look at a tutorial again and follow it closely.
You don't need to use a PreferenceActivity. The PreferenceFragment kind of replaced it. It is more flexible (it can be added to any kind of Activity) and the PreferenceActivity should only be used for apps which are supposed to work on Android versions below 3.0.
Hello,
I am currently trying to have a webview that listens to a long click and loads a website once longclicked.
However, it crashes and i would love to find out why, or how to fix it
I do have to state that this crash Occurs on Samsung and LG hardware, but not on the Nexus 4 or the Emulator (Nexus 7)
Code:
package com.example.homehub;
import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnLongClickListener;
import android.view.Window;
import android.view.WindowManager;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
public class MainActivity extends Activity {
WebView webView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Go Fullscreen (Just in case)
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
// Display the layout
setContentView(R.layout.activity_main);
// Define the Web View
webView = (WebView) findViewById(R.id.webView1);
// Setup
webView.getSettings().setCacheMode( WebSettings.LOAD_DEFAULT );
webView.setLongClickable(true);
// Handle Links internally
webView.setWebViewClient(new WebViewClient() { });
// Using Latest Chrome Client
webView.setWebChromeClient(new WebChromeClient());
// Browser Settings
webView.getSettings().setAllowFileAccess( true );
webView.getSettings().setAppCacheEnabled( true );
webView.getSettings().setJavaScriptEnabled( true );
// Go to Default URL
webView.loadUrl("http://google.com" );
// Long Click Listener
webView.setOnLongClickListener(new OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
// Grab URL
String webUrl = webView.getUrl();
// Show the URL (This works)
Toast.makeText(getApplicationContext(), webUrl, Toast.LENGTH_SHORT).show();
// This request crashes
webView.loadUrl("http://www.yahoo.com");
return true;
}
});
}
// Back Button behaviour (Either browser back, or exit)
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
WebView webView = (WebView) findViewById(R.id.webView1);
if(event.getAction() == KeyEvent.ACTION_DOWN){
switch(keyCode)
{
case KeyEvent.KEYCODE_BACK:
if(webView.canGoBack()){
webView.goBack();
}else{
finish();
}
return true;
}
}
return super.onKeyDown(keyCode, event);
}
}
And my Logcat:
Code:
12-01 01:48:40.579: W/dalvikvm(15534): threadid=1: thread exiting with uncaught exception (group=0x418eac08)
12-01 01:48:40.584: E/AndroidRuntime(15534): FATAL EXCEPTION: main
12-01 01:48:40.584: E/AndroidRuntime(15534): Process: com.example.homehub, PID: 15534
12-01 01:48:40.584: E/AndroidRuntime(15534): java.lang.NullPointerException
12-01 01:48:40.584: E/AndroidRuntime(15534): at com.android.org.chromium.content.browser.LongPressDetector.dispatchLongPress(LongPressDetector.java:158)
12-01 01:48:40.584: E/AndroidRuntime(15534): at com.android.org.chromium.content.browser.LongPressDetector.access$000(LongPressDetector.java:21)
12-01 01:48:40.584: E/AndroidRuntime(15534): at com.android.org.chromium.content.browser.LongPressDetector$LongPressHandler.handleMessage(LongPressDetector.java:58)
12-01 01:48:40.584: E/AndroidRuntime(15534): at android.os.Handler.dispatchMessage(Handler.java:102)
12-01 01:48:40.584: E/AndroidRuntime(15534): at android.os.Looper.loop(Looper.java:146)
12-01 01:48:40.584: E/AndroidRuntime(15534): at android.app.ActivityThread.main(ActivityThread.java:5653)
12-01 01:48:40.584: E/AndroidRuntime(15534): at java.lang.reflect.Method.invokeNative(Native Method)
12-01 01:48:40.584: E/AndroidRuntime(15534): at java.lang.reflect.Method.invoke(Method.java:515)
12-01 01:48:40.584: E/AndroidRuntime(15534): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291)
12-01 01:48:40.584: E/AndroidRuntime(15534): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107)
12-01 01:48:40.584: E/AndroidRuntime(15534): at dalvik.system.NativeStart.main(Native Method)
I am getting a NullPointerException after the build but once my phone tries to launch the app. I do not understand where the problem is. Im just learning to code and this app is simply supposed to make a toast pop up Long if the checkbox is clicked and short if it isnt.
Code:
package universaltruth.toastee;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity {
public CheckBox longToast = (CheckBox) findViewById(R.id.checkbox);
public EditText editText = (EditText) findViewById(R.id.toastText);
public int toastLength = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
addListenerOnlongToast();
}
public void addListenerOnlongToast(){
longToast.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
if(((CheckBox) view).isChecked()){
toastLength = '1';
}
}
});
}
public void toastMessage(View view){
String message = editText.getText().toString();
Toast.makeText(getApplicationContext(),message, (toastLength == 0) ? Toast.LENGTH_SHORT : Toast.LENGTH_LONG).show();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
LogCat:
02-08 12:48:34.718 6684-6684/universaltruth.toastee D/AndroidRuntime﹕ Shutting down VM
02-08 12:48:34.718 6684-6684/universaltruth.toastee W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x4191bda0)
02-08 12:48:34.718 6684-6684/universaltruth.toastee E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: universaltruth.toastee, PID: 6684
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{universaltruth.toastee/universaltruth.toastee.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2408)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2599)
at android.app.ActivityThread.access$900(ActivityThread.java:174)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5748)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107)
at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:132)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at android.app.Activity.findViewById(Activity.java:2014)
at universaltruth.toastee.MainActivity.<init>(MainActivity.java:19)
at java.lang.Class.newInstanceImpl(Native Method)
at java.lang.Class.newInstance(Class.java:1208)
at android.app.Instrumentation.newActivity(Instrumentation.java:1067)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2399)
************at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2599)
************at android.app.ActivityThread.access$900(ActivityThread.java:174)
************at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
************at android.os.Handler.dispatchMessage(Handler.java:102)
************at android.os.Looper.loop(Looper.java:146)
************at android.app.ActivityThread.main(ActivityThread.java:5748)
************at java.lang.reflect.Method.invokeNative(Native Method)
************at java.lang.reflect.Method.invoke(Method.java:515)
************at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291)
************at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107)
************at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:132)
************at dalvik.system.NativeStart.main(Native Method)
02-08 13:00:50.672 9121-9121/universaltruth.toastee I/SELinux﹕ Function: selinux_android_load_priority , priority [3] , priority version is VE=SEPF_SM-N910F_4.4.4_A024
02-08 13:00:50.672 9121-9121/universaltruth.toastee E/SELinux﹕ [DEBUG] get_category: variable seinfocat: default sensitivity: NULL, cateogry: NULL
02-08 13:00:50.672 9121-9121/universaltruth.toastee E/dalvikvm﹕ >>>>> Normal User
02-08 13:00:50.672 9121-9121/universaltruth.toastee E/dalvikvm﹕ >>>>> universaltruth.toastee [ userId:0 | appId:10384 ]
02-08 13:00:50.682 9121-9121/universaltruth.toastee E/SELinux﹕ [DEBUG] get_category: variable seinfocat: default sensitivity: NULL, cateogry: NULL
02-08 13:00:50.682 9121-9121/universaltruth.toastee D/dalvikvm﹕ Late-enabling CheckJNI
02-08 13:00:50.682 9121-9121/universaltruth.toastee I/libpersona﹕ KNOX_SDCARD checking this for 10384
02-08 13:00:50.682 9121-9121/universaltruth.toastee I/libpersona﹕ KNOX_SDCARD not a persona
02-08 13:00:50.752 9121-9121/universaltruth.toastee D/TimaKeyStoreProvider﹕ in addTimaSignatureService
02-08 13:00:50.762 9121-9121/universaltruth.toastee D/TimaKeyStoreProvider﹕ Cannot add TimaSignature Service, License check Failed
02-08 13:00:50.762 9121-9121/universaltruth.toastee D/ActivityThread﹕ Added TimaKesytore provider
02-08 13:00:50.922 9121-9121/universaltruth.toastee D/AndroidRuntime﹕ Shutting down VM
02-08 13:00:50.922 9121-9121/universaltruth.toastee W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x4191bda0)
02-08 13:00:50.922 9121-9121/universaltruth.toastee E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: universaltruth.toastee, PID: 9121
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{universaltruth.toastee/universaltruth.toastee.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2408)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2599)
at android.app.ActivityThread.access$900(ActivityThread.java:174)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5748)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107)
at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:132)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at android.app.Activity.findViewById(Activity.java:2014)
at universaltruth.toastee.MainActivity.<init>(MainActivity.java:16)
at java.lang.Class.newInstanceImpl(Native Method)
at java.lang.Class.newInstance(Class.java:1208)
at android.app.Instrumentation.newActivity(Instrumentation.java:1067)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2399)
************at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2599)
************at android.app.ActivityThread.access$900(ActivityThread.java:174)
************at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
************at android.os.Handler.dispatchMessage(Handler.java:102)
************at android.os.Looper.loop(Looper.java:146)
************at android.app.ActivityThread.main(ActivityThread.java:5748)
************at java.lang.reflect.Method.invokeNative(Native Method)
************at java.lang.reflect.Method.invoke(Method.java:515)
************at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291)
************at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107)
************at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:132)
************at dalvik.system.NativeStart.main(Native Method)
02-08 13:00:55.232 9121-9121/universaltruth.toastee I/Process﹕ Sending signal. PID: 9121 SIG: 9
Forgive me if I am not posting this correctly. This is my first time. I am open to any and all feedback. Thank you.
Your problem is that you initialize the longToast checkbox outside of a method. But findViewById only returns a result if called after a call to setContentView(...), which is done in onCreate. So: put your initialization code into onCreate, after setContentView and it will work fine
--------------------
Phone: Nexus 4
OS: rooted Lollipop LRX21T
Bootloader: unlocked
Recovery: TWRP 2.8.2.0
Masrepus said:
Your problem is that you initialize the longToast checkbox outside of a method. But findViewById only returns a result if called after a call to setContentView(...), which is done in onCreate. So: put your initialization code into onCreate, after setContentView and it will work fine
Click to expand...
Click to collapse
Hey Masrepus,
Thanks a bunch for answering me.
I have moved the initializations to the on create after the setContentView. I am still getting the null pointer exception. Do you have any further advice?
UniversalTruth said:
Hey Masrepus,
Thanks a bunch for answering me.
I have moved the initializations to the on create after the setContentView. I am still getting the null pointer exception. Do you have any further advice?
Click to expand...
Click to collapse
Can you edit the first post with the new code (and new logcat)?
Yes, grab a new log and post it on pastebin
Then link the log from here