Whats the easiest way to use a timer? I just want a simple timer to use as a countdown.
Thanks in advance
Here's a very basic countdown timer. You could also do it with a loop i guess, depending on what you want to do with it.
Code:
new CountdownTimer(30000, 1000) {
public void onTick(long millisUntilFinished) {
mTextField.setText("seconds remaining: " + millisUntilFinished / 1000);
}
public void onFinish() {
mTextField.setText("done!");
}
}.start();
source - http://developer.android.com/reference/android/os/CountDownTimer.html
It's better do not use the very simple timer. It's better to run Async or Runnable thread, but if you want timer, you can also use TimerTask.
Code:
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.Timer;
import java.util.TimerTask;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;
....
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Timer timer = new Timer();
timer.scheduleAtFixedRate(new MyTime(this), 1, 1000);
}
private class MyTime extends TimerTask {
DateFormat format = SimpleDateFormat.getTimeInstance(SimpleDateFormat.MEDIUM, Locale.getDefault());
public MyTime(Context ctx) {
// create internal instance
Context ctx;
}
@Override
public void run() {
currentTime = new Date();
// output something
Toast.makeText(ctx, "Time = " + format.format(currentTime), Toast.LENGTH_LONG).show();
}
}
Hello,
i am trying to use the ...1 and ...2 keys.
These are the two keys between "." and "Shift".
(see http://www.android-hilfe.de/attachm...-neuer-htc-desire-z-sammelthread-img_5169.jpg)
So I have written an app that gives my the keycodes via LogCat:
Code:
package default;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.widget.RelativeLayout.LayoutParams;
public class ShowKeycodeActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.main);
setContentView(new MyView(this));
}
class MyView extends View {
private static final String LOGID = "MxView";
String message = "No key pressed yet.";
MyView(Context context) {
super(context);
setFocusable(true);
}
@Override
protected void onDraw(Canvas canvas) {
Paint paint = new Paint();
canvas.drawText(message, 5, 20, paint);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent ev) {
Log.i(LOGID, keyCode+"");
invalidate();
return true;
}
}
}
All keys have a keycode but those special keys not.
HTC Sense can use these keys.
What can I do now?
It seems as if the kernel does not now that these keys exist?
Thank you
Tobi
I think only sense kernels support these keys
Sent from my HTC Vision using XDA App
With CyanogenMod 7 one can assign custom shortcuts to it.
But I want to use them as cursor left/right...
Try the Buttonremapper to do that!
Great. This is exactly what I've been looking for!
Thank you
Hi there,
I would like some advice on what I should look for if I want to implement the following basic scenario:
the app starts with an activity (call it Activity_1) which contains a button
on clicking the button, takes me to a different activity (call it Activity_2)
next time i start the app, it takes me directly to Activity_2
and Activity_1 won't be seen again
So how can I change the startup activity?
What's happening is that Android is not closing your app in between starts, it's only backgrounding it. One thing you could do is to override the onResume() method in your Activity_2 to call finish() if for instance you have set some variable, let's call it appPaused and it would act just like you had pressed the back button (which will also take you back to Activity_1).
Like below:
Code:
package com.test.example;
import android.app.Activity;
import android.os.Bundle;
public class Activity_2 extends Activity
{
boolean appPaused = false;
[user=439709]@override[/user]
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
}
[user=439709]@override[/user]
public void onPause()
{
appPaused = true;
}
[user=439709]@override[/user]
public void onResume()
{
if(appPaused)
finish();
}
}
thanks for the answer. i want to consider that the app is closed, like after restarting the device. i don't want it to be able to start with Activity_1 unless, let's say, i re-install the app.
i also had an idea about having a 3rd activity as the main one defined in the manifest, which on create changes to one of the other activities. but i don't know how that would be implemented. would it work?
octobclrnts said:
What's happening is that Android is not closing your app in between starts, it's only backgrounding it. One thing you could do is to override the onResume() method in your Activity_2 to call finish() if for instance you have set some variable, let's call it appPaused and it would act just like you had pressed the back button (which will also take you back to Activity_1).
Like below:
Code:
package com.test.example;
import android.app.Activity;
import android.os.Bundle;
public class Activity_2 extends Activity
{
boolean appPaused = false;
[user=439709]@override[/user]
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
}
[user=439709]@override[/user]
public void onPause()
{
appPaused = true;
}
[user=439709]@override[/user]
public void onResume()
{
if(appPaused)
finish();
}
}
Click to expand...
Click to collapse
Oh, I'm sorry, I misunderstood your question the first time. If you don't want an activity to be shown except for say the first time after an install (maybe it's a login screen or similar), I would in my main activity, use the SharedPreferences class to see if I have a preference set like below:
Code:
package com.test.example;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
public class Activity_Start extends Activity
{
boolean appPaused = false;
[user=439709]@override[/user]
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
if(!prefs.contains("loggedIn"))
{
//run activity only if never run before
startActivity(new Intent(this,Activity_Logon.class));
}
else
{
//do something else every other time
}
}
}
Code:
package com.test.example;
import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
public class Activity_Logon extends Activity
{
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
doLogon();
finish();
}
private void doLogon()
{
//logon code
SharedPreferences.Editor edit = PreferenceManager.getDefaultSharedPreferences(this).edit();
edit.putBoolean("loggedIn",true);
}
}
oh, ok. so from what I get SharedPreferences is a db where you can quickly save variables between sessions. great, I'll try it
octobclrnts said:
Oh, I'm sorry, I misunderstood your question the first time. If you don't want an activity to be shown except for say the first time after an install (maybe it's a login screen or similar), I would in my main activity, use the SharedPreferences class to see if I have a preference set like below:
Code:
package com.test.example;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
public class Activity_Start extends Activity
{
boolean appPaused = false;
[user=439709]@override[/user]
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
if(!prefs.contains("loggedIn"))
{
//run activity only if never run before
startActivity(new Intent(this,Activity_Logon.class));
}
else
{
//do something else every other time
}
}
}
Code:
package com.test.example;
import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
public class Activity_Logon extends Activity
{
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
doLogon();
finish();
}
private void doLogon()
{
//logon code
SharedPreferences.Editor edit = PreferenceManager.getDefaultSharedPreferences(this).edit();
edit.putBoolean("loggedIn",true);
}
}
Click to expand...
Click to collapse
K-RAD said:
oh, ok. so from what I get SharedPreferences is a db where you can quickly save variables between sessions. great, I'll try it
Click to expand...
Click to collapse
That's absolutely right. You can store Strings and primitive values indexed by String keys.
octobclrnts said:
That's absolutely right. You can store Strings and primitive values indexed by String keys.
Click to expand...
Click to collapse
in the second activity, doLogon() needed an edit.apply() at the end. it works somehow, but the problem is when i press the back button, it still takes me to the first activity, and i don'twant to see it anymore after i press the button. here's my code
Code:
package com.example.onetimeactivity;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
[user=439709]@override[/user]
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
if(!prefs.contains("loggedIn"))
{
//run activity only if never run before
Button b = (Button) findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener() {
[user=439709]@override[/user]
public void onClick(View arg0) {
startActivity(new Intent(MainActivity.this, SecondActivity.class));
}
});
}
else
{
//do something else every other time
startActivity(new Intent(this,SecondActivity.class));
}
}
}
Code:
package com.example.onetimeactivity;
import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
public class SecondActivity extends Activity
{
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
doLogon();
}
private void doLogon()
{
//logon code
SharedPreferences.Editor edit = PreferenceManager.getDefaultSharedPreferences(this).edit();
edit.putBoolean("loggedIn",true);
edit.apply();
}
}
i managed to resolve it by adding android:noHistory="true" to the manifest. however, now i really can't see the first activity, not even if i rebuild the code ))
K-RAD said:
in the second activity, doLogon() needed an edit.apply() at the end. it works somehow, but the problem is when i press the back button, it still takes me to the first activity, and i don'twant to see it anymore after i press the button. here's my code
Click to expand...
Click to collapse
K-RAD said:
in the second activity, doLogon() needed an edit.apply() at the end. it works somehow, but the problem is when i press the back button, it still takes me to the first activity, and i don'twant to see it anymore after i press the button. here's my code
Click to expand...
Click to collapse
Thanks for catching my mistake. You're right that it does need an apply (or before API level 9, commit()) call.
If you don't want to see the activity MainActivity anymore, then you have to make some changes to your structure. You should make an Activity that will be the one that always shows when the user opens the app. That activity is the one who should check the SharedPreferences for your entry. If the entry does not exist, it should call the one-time-activity. Then the one-time-activity should do it's work and save the entry and call finish() to go back to the main activity (the one you usually want to be shown). This way the activity stack will be correct for the back key functionality.
what it sounds like you want is something like a splash/logon screen
like previously said use sharedprefs.
in the splash/logon call the sharedpref and make the default false (I use booleans, you can use ints or strings):
so it would be like this
Code:
SharedPreferences settings;
SharedPreferences.Editor editor;
boolean splash;
[user=439709]@override[/user]
public void onCreate() {
settings = getSharedPreferences("settings", 0);
splash = settings.getboolean("splash", false);
editor = settings.edit();
if(splash == false){
setContentView(//the view you are using);
//do everything else you need to do
button.setonclicklistener(new OnClickListener(){
editor.putboolean("splash", true);
editor.commit();
finish();
});
}else{
//open up your second activity
finish();
}
if its a login screen, when the user clicks logout you would do the editor and change "splash" to false.
Hello,
I did a search on this forum and did not find a solution. This is my first time using the forum by the way. Anyways, I am developing my first application with one main activity that has two buttons each trying to open another activity.
When I try to run the app in Eclipse, I get the following error:
Error opening trace file: No such file or directory (2)
Any direction on how I can solve this would be greatly appreciated.
Absolutely! Here it is:
Code:
package com.mcrsports.mcr;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
[user=439709]@override[/user]
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//-----LATEST NEWS BUTTON-----
Button newsButton = (Button) findViewById(R.id.latestNewsButton);
newsButton.setOnClickListener(new OnClickListener() {
[user=439709]@override[/user]
public void onClick(View v) {
startActivity(new Intent(MainActivity.this, LatestNewsActivity.class));
}
});
//-----PARK LOCATIONS BUTTON-----
Button parksButton = (Button) findViewById(R.id.parkLocationsButton);
parksButton.setOnClickListener(new OnClickListener() {
[user=439709]@override[/user]
public void onClick(View v) {
startActivity(new Intent(MainActivity.this, ParkLocationsActivity.class));
}
});
}
[user=439709]@override[/user]
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
For me it happens as well and I have never had any problems.
However, here are some solutions: http://stackoverflow.com/questions/11446049/error-opening-trace-file-no-such-file-or-directory-2
Attached is my manifest file. Since I am new and have less than 10 posts, I could not successfully cut/paste within
Code:
block, so I pasted it into Notepad.
Thanks.
bueller?.......... bueller?..........bueller?
Hello,
So I am new to Java programming and I want to develop a small and simple app for plant identification. But the app crashes when I call a function wich set the text of a TextView. It happens in the OnCreate when I switch to a second activity. I tried to call the method with only comments in it. It also works when I create a new instance of the MainActivity class. It crashes when I try to set the text of a TextView from the MainActivity layout. It is probably a simple and basic problem, but I've been searching for my error for hours now and I still can't get it. I want to understand what's wrong and move on the the next step
I use the layout of MainActivity in Morphe activity.
Code:
package com.gobtron.cleidfougeres;
import android.content.Intent;
import android.graphics.Color;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
public class Morphe extends MainActivity {
TextView MorphTextTop;
TextView LongFrondeTextTop;
TextView FormeLimbeTextTop;
TextView DisposFrondeTextTop;
TextView DescTextTop;
TextView EspeceTextTop;
TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TopText topText = new TopText();
topText.SetText();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_morphe, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
And this is the code for the method in TopText method (located in TopText.java)
Code:
public class TopText {
public void SetText() {
MainActivity mainac = new MainActivity();
mainac.MorphTextTop.setText("eeeee");
}
}
gobtron said:
Hello,
So I am new to Java programming and I want to develop a small and simple app for plant identification. But the app crashes when I call a function wich set the text of a TextView. It happens in the OnCreate when I switch to a second activity. I tried to call the method with only comments in it. It also works when I create a new instance of the MainActivity class. It crashes when I try to set the text of a TextView from the MainActivity layout. It is probably a simple and basic problem, but I've been searching for my error for hours now and I still can't get it. I want to understand what's wrong and move on the the next step
I use the layout of MainActivity in Morphe activity.
Code:
package com.gobtron.cleidfougeres;
import android.content.Intent;
import android.graphics.Color;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
public class Morphe extends MainActivity {
TextView MorphTextTop;
TextView LongFrondeTextTop;
TextView FormeLimbeTextTop;
TextView DisposFrondeTextTop;
TextView DescTextTop;
TextView EspeceTextTop;
TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TopText topText = new TopText();
topText.SetText();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_morphe, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
And this is the code for the method in TopText method (located in TopText.java)
Code:
public class TopText {
public void SetText() {
MainActivity mainac = new MainActivity();
mainac.MorphTextTop.setText("eeeee");
}
}
Click to expand...
Click to collapse
Though you haven't posted a stack trace but I'm pretty sure a NullPointerException is being thrown in your code and this is because
Code:
public class TopText {
public void SetText() {
MainActivity mainac = new MainActivity();
mainac.MorphTextTop.setText("eeeee");
}
}
Is creating a new instance of Activity class MainActivity in which the field "MorphTextTop" is not initialized.......
All the fields in your main activity must be initialized in the onCreate method of the Activity after you have called " setContentView(R.layout.activity_main);"
The initialization would look something like
Code:
MorphTextTop = (TextView) findViewById(R.id."THIS_VIEWS_ID");
put your activity_main.xml here if you then I could give you the complete code.
What does your log say after the app crashes? And where's your actual MainActivity class?
Ok I finally found out the problem. Turns out that I was creating an instance of the TextView before setting the ContentView. Yay!