How to play audio using this code in Grid View

[Ajoo Bar]

Hi ,
I have been following this code on andriod developer site. This code displays pictures in a grid. What I want to do now is to play different sond each time user clicks on the image. How can I do that?
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
GridView gridview = (GridView) findViewById(R.id.gridview);
gridview.setAdapter(new ImageAdapter(this));

gridview.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
//
Intent myIntent = null;
if(position==0){
//Play some sound...
//MediaPlayer sound= MediaPlayer.create(this,R.raw.alif);
// sound.start();

}
if(position==1){
//Want to play some sound here...
Toast.makeText(Test.this, "" + "Baa",Toast.LENGTH_SHORT).show();
}
}

});
}

[Ulf Dittmer]

That's what the MediaPlayer.create and sound.start methods do, provided that raw/alif points to an audio file in a suitable format (maybe an MP3).

[Ajoo Bar]

Thanks
if(position==0){
//Play some sound...
MediaPlayer sound= MediaPlayer.create(this,R.raw.alif);
sound.start();

}

I get a compile error Invalid argument create(). Can I call it inside onItemClick method

[Ulf Dittmer]

Well, do you have a valid sound file of that name in the proper directory location?

[Ajoo Bar]

Yes I have a valid file, I can run using the same code out side the setOnItemClickListener() method, but I cant run it inside this method. I ge this error


The method create(Context, int) in the type MediaPlayer is not applicable for the arguments (new AdapterView.OnItemClickListener(){}, int)

[Ulf Dittmer]

Well, the first parameter must be a Context; if you use "this" inside of a OnItemClickListener, then that's not a Context.

[Ajoo Bar]

Thanks for the reply. So what should I pass instead of this.? Sorry It may be a stupid question, really trying to understand this concept

[Ulf Dittmer]

You can pass the Context to your OnItemClickListener implementation as a constructor argument.

[Ajoo Bar]

Thanks Here is what I did.

Created Instance variable
protected Context context;

super.onCreate(savedInstanceState);
setContentView(R.layout.main);
GridView gridview = (GridView) findViewById(R.id.gridview);
gridview.setAdapter(new ImageAdapter(this));

gridview.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
//
Intent myIntent = null;
MediaPlayer bismiallh2 =null;
if(position==0){
Toast.makeText(Alphabet.this, "" + "Alif",Toast.LENGTH_SHORT).show();
bismiallh2 = MediaPlayer.create(context,R.raw.alif);
bismiallh2.start();
}
if(position==1){
Toast.makeText(Alphabet.this, "" + "Baaa",Toast.LENGTH_SHORT).show();
bismiallh2 = MediaPlayer.create(context,R.raw.alif);
bismiallh2.start();

}
}

});
When I click on the image I get an error.
Logcat
04-06 17:10:20.181: DEBUG/AndroidRuntime(495): Shutting down VM
04-06 17:10:20.181: WARN/dalvikvm(495): threadid=1: thread exiting with uncaught exception (group=0x40015560)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): FATAL EXCEPTION: main
04-06 17:10:20.720: ERROR/AndroidRuntime(495): java.lang.NullPointerException
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at android.media.MediaPlayer.create(MediaPlayer.java:662)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at com.bismiallah.alphabet.Alphabet$1.onItemClick(Alphabet.java:42)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at android.widget.AdapterView.performItemClick(AdapterView.java:284)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at android.widget.AbsListView$PerformClick.run(AbsListView.java:1812)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at android.os.Handler.handleCallback(Handler.java:587)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at android.os.Handler.dispatchMessage(Handler.java:92)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at android.os.Looper.loop(Looper.java:123)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at android.app.ActivityThread.main(ActivityThread.java:3683)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at java.lang.reflect.Method.invokeNative(Native Method)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at java.lang.reflect.Method.invoke(Method.java:507)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
04-06 17:10:20.720: ERROR/AndroidRuntime(495): at dalvik.system.NativeStart.main(Native Method)
04-06 17:10:20.729: WARN/ActivityManager(62): Force finishing activity com.bismiallah.alphabet/.Alphabet
04-06 17:10:21.320: WARN/ActivityManager(62): Activity pause timeout for HistoryRecord{407592b0 com.bismiallah.alphabet/.Alphabet}

[Ulf Dittmer]

And what do you deduce from that?

[Ajoo Bar]

Null pointer exception... DO I have to context prob is null?

[Ulf Dittmer]

Well, *something* is null, that's for sure. You can do some debugging to find out *what* is null, or you can try to reason from the code you posted - which does not include anything that would set the context variable to anything other than null.