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Hi all,
I am using eVC++ 4.0, and i've dynamically created a CListView like this:
Code:
lv.Create(0,_T(""),WS_CHILD|WS_VISIBLE,r,this,5);
but I dont know how to handle the events of this control... any ideas??
Mohammad
To get events from a listview (win32) I normally subclass it. I use the subclassing routine to post a message back to the parent when the user is doing something like tapping on it, then the windows routine can check whats selected etc and act on it. Is subclassing possible in mfc ?( I don't use it).
Thank u
but can anybody post some code??
thnx
Ok, I am a bit lazy to look up code at the moment, but here's something:
Yes, subclassing is possible in MFC. You just derive your class from the basic class provided like this:
Code:
class MyListView : pubic CListView
Then you add message handlers in the normal matter.
EDIT: The following passage is incorrect:
But I think subclassing may not be necessary in you case. List box controls send WM_COMMAND messages with notifications of major events like selection change to the parent window. All you have to do is to create a WM_COMMAND handler in your parent class.
Sorry I was thinking of ListBox not list view when I wrote it.
To manually add message handlers you need to put macros like ON_MESAGE or ON_COMMAND in the DECLARE_MESSAGE_MAP section of the class cpp file. All the detaisl are available on MSDN.
Are you saying that a listview will send the same WM_COMMAND as a list box in mfc? Dose this also happen in win32 made listviews. I have always thought it was a bit too tedious to find out when the user taps an item in the listview.
After reading your post levenum I had a quick look and it says that a WM_NOTIFY gets sent to the parent with a LVN_ITEMCHANGED for example. I had not used the LVN_**** because when I looked at them there was none that seem to deal with selections. I would guess that LVN_ITEMACTIVATE or LVN_ODSTATECHANGED would be usefull for this but then a second tap would not be picked up still leaving me wanting subclassing in many situations to get the users tap.
Ok, I have read what u wrote guys and my problem is almost solved, I used the OnNotify() method to handle messages sent from child controls like this:
Code:
BOOL CTest2Dlg::OnNotify(WPARAM wParam, LPARAM lParam, LRESULT* pResult)
{
// TODO: Add your specialized code here and/or call the base class
if(wParam ==5 ) //5 is control ID
{
NMHDR *ph =(NMHDR*)lParam;
if(ph->code==NM_CLICK)
MessageBox("Click");
else if(ph->code==HDN_ITEMCLICK)
MessageBox("Item Click");
else
{
CString str;
str.Format("%d",ph->code);
MessageBox(str);
}
}
return CDialog::OnNotify(wParam, lParam, pResult);
}
Now there still a very small prolem: what messages should I handle for 'Selected Item Changed' event ?? I know its easy but I couldnt find it
Regards
mohgdeisat: I am sorry, I made a mistake about WM_COMMAND.
OdeeanRDeathshead is right, I was thinking of a list box not list view.
To make up for this, here is some sample code from a win32 dialog app that uses list view control. I hope it will be of some help:
Code:
//this is from the dialog window function:
case WM_NOTIFY: //handle events:
nmhdr = (LPNMHDR)lParam;
switch (nmhdr->idFrom)
{
case IDC_LEDLIST: //list control ID.
return OnLEDListEvent(hwndDlg, (LPNMLISTVIEW)lParam);
break;
}
break;
BOOL OnLEDListEvent(HWND hwndDlg, LPNMLISTVIEW nmlv)
{
/////
// Handles list view control notification messages
switch (nmlv->hdr.code)
{
case LVN_ITEMCHANGED:
return OnLEDListItemChanged(hwndDlg, nmlv);
break;
}
return 0;
}
BOOL OnLEDListItemChanged(HWND hwndDlg, LPNMLISTVIEW nmlv)
{
if (ListView_GetSelectionMark(nmlv->hdr.hwndFrom) != nmlv->iItem) return 0;
/* do what you need here */
return 0;
}
Don't mind the fact that I used 3 different functions. This is part of a bigger program and I am trying to keep things well organized without resorting to classes.
As I understand it, LVN_ITEMCHANGE is received for different reasons so I try to handle only the one coming from selected item. LVN_ITEMACTIVATE is only sent when you double click the item so if you just want to catch selection change you need to use LVN_ITEMCHANGE.
Once again, sorry for confusing you before.
thanx pals, good job!!!
I think my problem is now solved with ur help :wink:
Mohammad
Ok guys, I said that my problem was solved, yet, another problem arises...
When the list view is in the report mode, how can I determine when a header button is clicked, and determine which one was clicked???????
thanx in advance
To identify a header column click, you need to handle the WM_NOTIFY/HDN_ITEMCLICK message. Normally this message will be received by the header's parent control (i.e. the listview) -- some frameworks may redirect the message to the header control itself. I haven't worked with MFC in 10 years so I can't really if it reflects notification messages back to the control.
If you're trying to implement column sort, do yourself a favor and check out the Windows Template Library (WTL) at sourceforge.net. It's a set of C++ template classes that provide a thin yet useful wrapper around the standard Windows UI components. One of the classes is a sortable listview control. I've been using WTL with big Windows for more than 5 years -- you couldn't pay me to go back to MFC.
hi,
I have seen the WTL library and it seems very useful and time-saver, but I have a couple of questions about it:
1. can WTL 8.0 be installed with VC++ 6.0, specifically the appwizard stuff??how?? I see only javascript files of vc7.0 and 7.1 and 8.0!!
2. is there a good documentation about those classes??
Mohammad
I don't know about WTL 8; I'm still using WTL 7.5 with VS .Net 2003 for all my Win32 development. My guess is that it wouldn't work too well, as WTL is based on ATL, which has substantially changed between VC 6 and 7.
Good references for WTL include www.codeproject.com/wtl, and the WTL group over at Yahoo groups (reflected at www.gmane.org).
I recently saw this tread:
http://forum.xda-developers.com/showthread.php?t=370632
i liked the idea, and when i thought about it, gesture recognition didn't seem to hard. And guess what - it really wasn't hard
I made a simple application recognizing gestures defined in an external configuration file. It was supposed to be a gesture launcher, but i didn't find out how to launch an app from a winCE program yet. Also, it turned out to be a bit to slow for that because of the way i draw gesture trails - i'd have to rewrite it almost from scratch to make it really useful and i don't have time for that now.
So i decided to share the idea and the source code, just to demonstrate how easy it is to include gesture recognition in your software.
My demo app is written in C, using XFlib for graphics and compiled using CeGCC so you'll need both of them to compile it (download and install instructions are on the Xflib homepage: www.xflib.net)
The demo program is just an exe file - extract it anywhere on your device, no installation needed. You'll also need to extract the gestureConfig.ini to the root directory of your device, or the program won't run.
Try some of the gestures defined in the ini (like 'M' letter - 8392, a rectangle - 6248, a triangle - 934), or define some of your own to see how the recognition works. Make sure that you have a string consisting of numbers, then space of a tabulator (or more of them) and some text - anything will do, just make sure that there's more than just the numbers in each line. Below you can set the side sensitivity to tweak recognition (see the rest of the post for description on how it works). Better leave the other parameter as it is - seems to work best with this value.
Now, what the demo app does:
It recognizes direction of drawn strokes, and prints them on the bottom of the screen as a string of numbers representing them (described bellow). If a drawn gesture matches one of the patterns in the config file, the entire drawn gesture gets highlited. It works the best with stylus, but is usable with finger as well.
Clicking the large rectangle closes the app.
And how it does it:
The algorithm i used is capable of recognizing strokes drawn in eight directions - horizontally, vertically and diagonally. Directions are described with numbers from 1 to 9, arranged like on a PC numerical keyboard:
Code:
7 8 9
4 6
1 2 3
So a gesture defined in config as 6248 is right-down-left-up - a ractangle.
All that is needed to do the gesture recognition is last few positions of the stylus. In my program i recorded the entire path for drawing if, but used only 5 last positions. The entire trick is to determine which way the stylus is moving, and if it moves one way long enough, store this direction as a stroke.
The easiest way would be to subtract previous stylus position from current one, like
Code:
vectorX=stylusX[i]-stylusX[i-1];
vectorY=stylusY[i]-stylusY[i-1];
[code]
But this method would be highly inaccurate due to niose generated by some digitizers, especially with screen protectors, or when using a finger (try drawing a straight line with your finger in some drawing program)
That's why i decided to calculate an average vector instead:
[code]
averageVectorX=((stylusHistoryX[n]-stylusHistoryX[n-5])+
(stylusHistoryX[n-1]-stylusHistoryX[n-5])
(stylusHistoryX[n-2]-stylusHistoryX[n-5])
(stylusHistoryX[n-3]-stylusHistoryX[n-5])
(stylusHistoryX[n-4]-stylusHistoryX[n-5]))/5;
//Y coordinate is calculated the same way
where stylusHistoryX[n] is the current X position of stylus, and stylusHistoryX[n-1] is the previous position, etc.
Such averaging filters out the noise, without sacrificing too much responsiveness, and uses only a small number of samples. It also has another useful effect - when the stylus changes movement direction, the vector gets shorter.
Now, that we have the direction of motion, we'll have to check how fast the stylus is moving (how long the vector is):
Code:
if(sqrt(averageVectorX*averageVectorX+averageVectorY*averageVectorY)>25)
(...)
If the vector is long enough, we'll have to determine which direction it's facing. Since usually horizontal and vertical lines are easier to draw than diagonal, it's nice to be able to adjust the angle at which the line is considered diagonal or vertical. I used the sideSensitivity parameter for that (can be set in the ini file - range its is from 0 to 100). See the attached image to see how it works.
The green area on the images is the angle where the vector is considered horizontal or vertical. Blue means angles where the vector is considered diagonal. sideSensitivity for those pictures are: left one - 10, middle - 42 (default value, works fine for me ), right - 90. Using o or 100 would mean that horizontal or vertical stroke would be almost impossible to draw.
to make this parameter useful, there are some calculations needed:
Code:
sideSensitivity=tan((sideSensitivity*45/100)*M_PI/180);
First, the range of the parameter is changed from (0-100) to (0-22), meaning angle in degrees of the line dividing right section (green) and top-right (blue). hat angle is then converted to radians, and tangent of this angle (in radians) is being calculated, giving slope of this line.
Having the slope, it's easy to check if the vector is turned sideways or diagonal. here's a part of source code that does the check, it is executed only if the vector is long enough (condition written above):
Code:
if( abs(averageVectorY)<sideSensitivity*abs(averageVectorX) ||
abs(averageVectorX)<sideSensitivity*abs(averageVectorY)) //Vector is turned sideways (horizontal or vertical)
{
/*Now that we know that it's facing sideways, we'll check which side it's actually facing*/
if( abs(averageVectorY)<sideSensitivity*averageVectorX) //Right Gesture
gestureStroke='6'; //storing the direction of vector for later processing
if( abs(averageVectorY)<sideSensitivity*(-averageVectorX)) //Left Gesture
gestureStroke='4';
if( abs(averageVectorX)<sideSensitivity*(averageVectorY)) //Down gesture
gestureStroke='2';
if( abs(averageVectorX)<sideSensitivity*(-averageVectorY)) //Up gesture
gestureStroke='8';
}
else
{ //Vector is diagonal
/*If the vector is not facing isdeways, then it's diagonal. Checking which way it's actually facing
and storing it for later use*/
if(averageVectorX>0 && averageVectorY>0) //Down-Right gesture
gestureStroke='3';
if(averageVectorX>0 && averageVectorY<0) //Up-Right gesture
gestureStroke='9';
if(averageVectorX<0 && averageVectorY>0) //Down-Left gesture
gestureStroke='1';
if(averageVectorX<0 && averageVectorY<0) //Up-Left gesture
gestureStroke='7';
}
Now, we have a character (i used char type, so i can use character strings for string gestures - they can be easily loaded from file and compared with strcmp() ) telling which way the stylus is moving. To avoid errors, we'll have to make sure that the stylus moves in the same direction for a few cycles before storing it as a gesture stroke by increasing a counter as long as it keeps moving in one direction, and resetting it if it changes the direction. If the counter value is bigger than some threshold (pathSensitivity variable is used as this threshold in my program), we can store the gestureStroke value into a string, but only if it's different from previous one - who needs a gesture like "44444" when dragging the stylus left?
After the stylus is released, you'll have to compare generated gesture string to some patterns (eg. loaded from a configuration file), and if it matches, do an appropriate acton.
See the source if you want to see how it can be done, this post already is quite long
If you have any questions, post them and i'll do my best to answer.
Feel free to use this method, parts of, or the entire source in your apps. I'm really looking forward to seeing some gesture-enabled programs
Very nice work. Reading your post was very insightful, and I hope this can provide the basis for some new and exciting apps!
great app... and well done for not just thinking that seems easy... but actually doing it...
ive been a victim of that myself
very nice work man.. one question in which tool did you write code.. i mean it looks like C but how you test and all..
Great app, i see that it is just proof of concept at this stage, but i see that it can be used in future applications control
Continiue with your great work
nik_for_you said:
very nice work man.. one question in which tool did you write code.. i mean it looks like C but how you test and all..
Click to expand...
Click to collapse
It is C, (no "++", no "#", no ".NET", just god old C ) compiled with opensource compiler CeGCC (works under linux, or under windows using cygwin - a unix emulator), developed in opensource IDE Vham (but even a notepad, or better notepad++ would do), tested directly on my Wizard (without emulator). I used XFlib which simplifies graphics and input handling to a level where anyone who ever programed anything at all should be able to handle it - it providea an additional layer between the programmer and the OS. You talk to Xflib, and Xflib talks to the OS. I decided to use this library, because i wanted to try it out anyway.
If i decide to rewrite it and make an actual launcher or anything else out of it, i'll have to use something with a bit faster and more direct screen access (probably SDL, since i already done some programing for desktop PC with it) - XFlib concentrates on usage of sprites - like 2D console games. every single "blob" of the gesture trail is a separate sprite , which has to be drawn each time the screen is refreshed - that is what slows down the app so much. The gesture recognition itself is really fast.
Very good program i just test it and it works very well some combinaison are pretty hard to realize but i like this blue point turning red with command2 and 934. Goond luck , i'll continue to see your job maybe you'll code a very interesting soft.
Interesting work.... would like to see this implemented in an app, could be very useful.
If you want I have some code I did for NDS coding, and which I ported on PocketPC for XFlib.
It works perfectly well and I use it in Skinz Sudoku to recognize the drawn numbers.
The method is pretty simple : when the stylus is pressed, enter the stylus coordinates in a big array. And when it's released, it takes 16 points (could be changed depending on what you need) at the same distance from each other, checks the angle, and gives you the corresponding 'char'.
To add new shapes, it's just a 15 character string which you link to any char (like, link right movement to 'r', or 'a', or a number, or whatever ^^). It works for pretty much any simple shape, and I even used it to do a graffitti-like thing on NDS which worked really well
Hey!
How do you get the last Stylus Positions?
and how often do you read them out
I want to realice such a code under vb.net, but I don't know how i should read out the last stylus positions, to get them perfectly for such calculations
Code:
Private Sub frmGesture_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseMove
If StylusJump = 1 Then
StylusJump += 1
If (CurrentStylusPosition.X <> frmGesture.MousePosition.X) Or (CurrentStylusPosition.Y <> frmGesture.MousePosition.Y) Then
LastStylusPosition(9).X = LastStylusPosition(8).X
LastStylusPosition(9).Y = LastStylusPosition(8).Y
LastStylusPosition(8).X = LastStylusPosition(7).X
LastStylusPosition(8).Y = LastStylusPosition(7).Y
LastStylusPosition(7).X = LastStylusPosition(6).X
LastStylusPosition(7).Y = LastStylusPosition(6).Y
LastStylusPosition(6).X = LastStylusPosition(5).X
LastStylusPosition(6).Y = LastStylusPosition(5).Y
LastStylusPosition(5).X = LastStylusPosition(4).X
LastStylusPosition(5).Y = LastStylusPosition(4).Y
LastStylusPosition(4).X = LastStylusPosition(3).X
LastStylusPosition(4).Y = LastStylusPosition(3).Y
LastStylusPosition(3).X = LastStylusPosition(2).X
LastStylusPosition(3).Y = LastStylusPosition(2).Y
LastStylusPosition(2).X = LastStylusPosition(1).X
LastStylusPosition(2).Y = LastStylusPosition(1).Y
LastStylusPosition(1).X = CurrentStylusPosition.X
LastStylusPosition(1).Y = CurrentStylusPosition.Y
CurrentStylusPosition.X = frmGesture.MousePosition.X
CurrentStylusPosition.Y = frmGesture.MousePosition.Y
End If
Dim LabelString As String
Dim iCount As Integer
LabelString = "C(" & CurrentStylusPosition.X & "\" & CurrentStylusPosition.Y & ")"
For iCount = 1 To 9
LabelString = LabelString & " " & iCount & "(" & LastStylusPosition(iCount).X & "\" & LastStylusPosition(iCount).Y & ")"
Next
lblGesture.Text = LabelString
ElseIf StylusJump <= 3 Then
StylusJump += 1
Else
StylusJump = 1
End If
End Sub
Sorry, i didn't notice your post before. I guess that you have the problem solved now, that you released a beta of gesture launcher?
Anyway, you don't really need 10 last positions, in my code i used only 5 for calculations and it still worked fine.
Nice thread, thanks for sharing.
Human-,achine interface has always been an interesting subject to me, and the release of ultimatelaunch has sparked an idea. I am trying to acheive a certain look-and-feel interface - entirely using components that are today screen and ultimatelaunch compatible. Basically a clock strip with a few status buttons at the top, and an ultimatelaunch cube for the main lower portion of the screen - gesture left/right to spin the cube, and each face should have lists of info / icons scrolled by vertical gesture. I'm talking big chunky buttons here - tasks, calendar appts, (quick) contacts, music/video playlists - all vertical lists, one item per row, scrolling in various faces of the cube.
Done the top bit using rlToday for now. Set it to type 5 so scrollbars never show for the top section. All good. Cobbling together bits for the faces, but few of the apps are exactly what I want, some (like that new face contacts one) are pretty close, and being a bit of an armchair coder, I thought now would be a good opportunity to check out WM programming and see if I can't at least come up with a mockup of what I want if not a working app.
I was wondering if anyone could advise me on whether I should bother recognising gestures in such a way as this. Does WM not provide gesture detection for the basic up, down, left, right? Actually, all the stuff I have in mind would just require up/down scrolling of a pane - I was thinking that I may well not need to code gesture support at all, just draw a vertical stack of items, let it overflow to create a scrollbar and then just use the normal WM drag-to-scroll feature (if it exists) to handle the vertical scrolling by gesture in the face of the cube. I would rather keep the requirements to a minimum (eg touchflo), both for dependancy and compatibility reasons, so maybe doing the detection manually would be the "way to go", I dunno.
Did you release source with the app launcher? A library maybe? I intend to go open source with anything I do, so if you are doing the same then I would love to have access to your working code
Nice work man.
Impressive.
Hi,
I have been trying to get to grips with Android.
First off I guess, any good books you can recommend? I have Hello, Android which has some good examples, but some of the things leave me a little cold in that it seems overly simplistic and then seems to fail to pick up on some latter crucial points, not least about creating custom adapters.
Anyhow, back to the questions.
Firstly, various devices, like the Samsung Galaxy S uses a "blue" summary line in its settings menus. Looks good. But if you want to mimic that style outside of a summary menu, is it possible to get details of system colours?
Secondly, in terms of icon design, tab icons in as defined in the Android SDK seem to suggest using a Grey icon for off and a white icon for on. This seems to bit a bit foolish when the tabs are white.... and most of the other programs I've seen that use tabs have Grey icons for on and white icons for off! Thoughts?
Third, back to this book, one of the examples it gives, is a way to load data from a SQL database using Cursors and SimpleAdapters. Im guessing if I want anything more than a relatively simple list and data pulled from the database, that Im going to need to use a CustomAdapter.
In terms of these cursors though, some of the code does this in the onCreate:
Code:
Cursor cursor
CustomDatabaseHelper test = new CustomDatabaseHelper(this);
try {
cursor = getData();
showData(cursor);
} finally {
test.close();
}
I think I found a couple of problems with that... The CustomDatabaseHelper and Cursor are both local to the onClick method and therefore if I need to access these via a Buttons onClick Im stuffed unless I make them private/public to the class. I don't know the best way around this TBH, what would you suggest? I guess I could define another CustomDatabaseHelper in the onClick method, but Im not sure whether it is a good idea to keep opening all these references.
Plus as well in onClick, you can't give a context of "this" because it's it's not a context there its an OnClickListener?
Code:
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
}
}
And there must be a better way of refreshing the data set? I've tried cursor.notify, test.notify and globalising the adapter and doing adapter.notifyDataSetChanged(); things still don't refresh.
Im going to guess this is a pretty basic and common issue for newcomers trying to understand this that super context intent.
I think Im getting there, Im just trying to get a bit of background to a few of the basic issues Im having a bit of trouble with and find out what the best way to handle the issues are.
Oh, the showData function (which I call after any data change at the moment), does this:
Code:
SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.test_item, cursor, Columns, TO);
I think that'll do for now, as my next issues are about SQL, Dates and Formatting.
Thanks
Simon
I think my problem stems around this book of mine... I can do a "notifyDataSetChanged()" on the adapter provided I don't do the "test.close" as above.
This suggests to me the DB Helper should be open across the activity lifetime.
Is that right?
Hello all! I'm somewhat new to Android development, I'm using eclipse to do all of my development. Right now I am working on an "away message text" application. I am having trouble with database query returning a string of the first index of data. Here is my code where i am trying to pull data from the database. This is being done inside my ReceiveText class, which extends BroadcastReceiver.
mDbHelper = new TextsDbAdapter(context);
mDbHelper.open();
getText = mDbHelper.fetchText(0);
message = getText.getString(getText.getColumnIndex(mDbHelper.KEY_BODY)).toString();
The error that I am getting is Cursor index out of bounds...any recommendations? Thanks!
you always start out of bounds.... you have to moveToFirst() first...
Thanks. Would I moveToFirst() before I fetchText()?
you're probably going to have to change how the fetchText method is implemented.
you'll probably want something like
Code:
public String fetchText(int id){
Cursor c = getContentResolver().query( uri,
new String[] { <name_of_text_column> } ,
"_id == " + id, null, null);
String text = null;
if( c != null ){
if( c.moveToFirst() ){
text = c.getString( c.getColumnIndex( <name_of_text_column> ) );
}
c.close();
}
return text;
}
Thanks. The method I have for fetchText returns a Cursor, however I made another method that returns a string, similar to what you recommended. For some reason, there is something wrong with the rowid sending in, I want to just get the first one, if I'm not mistaken, wouldn't it be 0? I have a seperate ReceiveText.java class, which extends Broadcast Receiver. The part where the messages are stored into the database is very similar to androids notepad demo. When a text is received, I want the ReceiveText class to query the database and just pull the first text that was actually stored into the database. I have 3 columns, KEY_ROWID, KEY_TITLE, and KEY_BODY. For some reason there is an issue when trying to query the database from the ReceiveText class. Any ideas that would make better sense or be easier to implement? Any help is much appreciated.
oh, right. I wasn't paying attention and for some reason I thought it was returning a string. I see now that it's obviously a cursor..
what you are doing sounds fine but you sure really look at the database on the phone/emulator.
open up adb and type
Code:
sqlite3 /data/data/<name_of_app>/databases/<name_of_db>
then you can do
Code:
select * from <name_of_table>
personally, I find it way easier to read if you change the mode with a ".mode line" command(the dot is important).
that should give you a good idea of why it is not working properly.
How do I open up the adb? I looked online, and it says i can run it through command line, or terminal since I use ubuntu, but I'm not sure exactly how to open it. Apologies for my noobness with android development i'm trying to learn!
if you're running it on a phone/tablet, you'll have to set up the adb drivers
but if you're just using the emulator, you're fine
Code:
cd /<path_to_sdk>/platform-tools/
./adb devices ##this should list the device. if not you have a problem.
./adb shell
and now you can execute commands on the device, like sqlite3
Awesome, I got that to work, and i can see the three "texts" that i've added to the database...looks like this...
1|Sleeping|Sleeping...text you when I wake up.
2|Driving|Driving right now...text you when I'm done.
3|Xbox|Playing xbox...text you later.
So this means that my database works. The numbers 1,2, and 3 are the KEY_ROWID, sleeping, driving, and xbox are the KEY_TITLE, and the third part is the KEY_BODY.
For some reason the ReceiveText class is having trouble pulling this information from the database, I really think it has something to do with when i Query the database, it asks for a columnindex, and i am putting a 0 as the parameter. Any ideas? Thanks again for all your help. It's a great learning process.
yeah, there doesn't seem to be a column with _id == 0
that is strange. when you defined it did you use "integer primary key autoincrement"? This should start at 0, I believe.. maybe you deleted your first entry at some point?
try it with 1 and see if that works.
Man, thanks so much for your help...it works! Here is how I did it from the ReceiveText class.
mDbHelper = new TextsDbAdapter(context);
mDbHelper.open();
getText = mDbHelper.fetchText(1);
message = getText.getString(2).toString();
getText is a Cursor type, and message is a String type.
I really appreciate the help, I understand a lot more now. My next step is to set the text to use without having to specify from the ReceiveText class...any suggestions? I was thinking adding another column in the database that would hold either a 1 or 0, and if it is selected, it updates the database and changes that field to a 1, then the ReceiveText class will query the database to return the field that has the 1...make sense? lol
Just to clear this up a bit for those still a little fuzzy:
Code:
Cursor c = db.query(TABLE_NAME3, new String[] {NAMESHORT, LAPTIME, LAPNUMBER}, null ,null, null, null, orderBy);
The column indexes are what you have in the "new String[]" area whether you have 1 or 50 items. So, NAMESHORT is index 0, LAPTIME is index 1 and LAPNUMPER is index 2. It's NOT the column number of where it is in the table
Just a personal preference of mine, but I code all this in the database methods and return what I need from there. Seeing hard-coded numbers in a program always bothers me. Instead of returning cursors I'll return a StringBuilder or ArrayList or whatever. Just sayn'
Hi guys.
New to Android Development and was wondering if there was some way of taking the users input to create an activity? For example say the user is going through the process of setting up a profile of themself. One of the questions is "how many pets do you have?". The user inputs "4" and then clicks the 'Next' button (which opens the next activity).
How would I take the users input of "4" to create four editText objects in the next activity so that the user can now input the name's of his/her's pets?
I'm an ok-ish programmer (have never touched XML before) so you don't need to go into detail I just don't know how I would access this variable to create the four editText objects. From what I've found you can't add strings to the resources at runtime.
Don't bother replying, I've solved my problem. Just need to create a dynamic layout in JAVA