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我正在开发一个应用程序，它读取 sd 卡上的音频文件并在按下开始按钮时播放它们。奇怪的是，该应用程序在我的 Droid RAZR 上运行良好，但在其他设备上时崩溃。我已经在我父亲的 Droid RAZR 以及我的朋友三星 Galaxy S2 和我的旧 Droid Incredible 上尝试过它并且崩溃了。我将手机中的 SD 卡放入了我的 Incredible 中，它曾经工作过一次，但是当我将它放入我父亲的时，我并没有得到相同的结果。

这是带有光标的方法的代码：

private void init_phone_music_grid() {
    System.gc();
    String[] proj = { MediaStore.Audio.Media.DURATION,
            MediaStore.Audio.Media.DATA,
            MediaStore.Audio.Media.TITLE,
            MediaStore.Audio.Media.ARTIST }; // was originally set to MediaStore.Video.Media.ARTIST



    musiccursor = managedQuery(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
            proj, MediaStore.Audio.Media.DURATION + ">= 65000", null, null );
    count = musiccursor.getCount(); //causes force close, when plugged in sometimes; not an issue with StateCheck class
    musiclist = (ListView) findViewById(R.id.lvTrackList);
    musiclist.setAdapter(new MusicAdapter(getApplicationContext()));

    musiclist.setOnItemClickListener(musicgridlistener);
    mMediaPlayer = new MediaPlayer();
}

这是 OnCreate 方法的代码：

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    initializeVars();

    init_phone_music_grid();
    //countDown();
    trackList.setCacheColorHint(Color.GRAY);

    start.setEnabled(false);
    pause.setEnabled(false);
    reset.setEnabled(false);
    trackList.setVisibility(View.INVISIBLE);
    instructions.setVisibility(View.VISIBLE);

    //*** USED FOR TESTING!!! ***//
    Calendar date = Calendar.getInstance();
    if(date.get(Calendar.DAY_OF_YEAR) >= 6) {
        AlertDialog.Builder builder1 = new AlertDialog.Builder(this);
        builder1.setCancelable(false);
        builder1.setMessage("This test version of Musercise has ended! Buy the real one if you want to use it!");
        builder1.setPositiveButton("Close",
                new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int id) {
                dialog.cancel();
                finish();
            }
        });

        AlertDialog alert11 = builder1.create();
        alert11.show();
    }
    // END TESTING

    start.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            chrono.setBase(SystemClock.elapsedRealtime() + timeWhenStopped);
            chrono.start();

            for(int i = 0; i <= trackList.getCount() - 1; i++) {
                randomArray[i] = i;
            }
            shuffleArray(randomArray);

            if(!isPaused) {
                MyTimerTask myTask = new MyTimerTask();
                timer = new Timer();
                timer.schedule(myTask, (totalTimeLong)*60000);                  
            }else if(resumeNeeded){
                MyTimerTask myTask = new MyTimerTask();
                timer = new Timer();
                timer.schedule(myTask, timeRemainingAfterPause);
                resumeNeeded = false;
                pause.setEnabled(true);
            }

            if(!mMediaPlayer.isPlaying()) {
                music_column_index = musiccursor
                        .getColumnIndexOrThrow(MediaStore.Audio.Media.DATA);
                musiccursor.moveToPosition(randomArray[0]);
                String filename = musiccursor.getString(music_column_index);

                    try {
                        mMediaPlayer.setDataSource(filename);
                    } catch (IllegalArgumentException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    } catch (IllegalStateException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    try {
                        mMediaPlayer.prepare();
                    } catch (IllegalStateException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    mMediaPlayer.start();

            }

            if(mMediaPlayer.isPlaying()) {
                includeWarmUp.setEnabled(false);
                includeCoolDown.setEnabled(false);
                test.setEnabled(false);
                start.setEnabled(false);
                trackList.setVisibility(View.VISIBLE);
                instructions.setText("Track List:");
            }

            isPaused = false;
            drawer.setBackgroundResource(R.drawable.run);
        }
    });

    pause.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            isPaused = true;
            resumeNeeded = true;
            timeWhenStopped = chrono.getBase() - SystemClock.elapsedRealtime();
            chrono.stop();
            mMediaPlayer.pause();

            long elapsedMillis = SystemClock.elapsedRealtime() - chrono.getBase();
            timer.cancel();
            timeRemainingAfterPause = totalTimeLong*60000 - elapsedMillis;

            start.setEnabled(true);
            pause.setEnabled(false);

            drawer.setBackgroundResource(R.drawable.pause);
        }
    });

    reset.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            chrono.stop();
            timeWhenStopped = 0;
            chrono.setBase(SystemClock.elapsedRealtime());
            mMediaPlayer.reset();


            start.setTextColor(Color.BLACK);
            pause.setTextColor(Color.BLACK);

            includeWarmUp.setEnabled(true);
            includeCoolDown.setEnabled(true);
            test.setEnabled(true);
            start.setEnabled(true);
            pause.setEnabled(true);
            trackList.setEnabled(true);


            drawer.setBackgroundResource(R.drawable.ic_launcher);
        }
    });


    test.setOnSeekBarChangeListener(this);
}

Logcat 崩溃时：

01-03 19:41:01.678: E/AndroidRuntime(499):  android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
01-03 19:41:01.678: E/AndroidRuntime(499):  at android.database.AbstractCursor.checkPosition(AbstractCursor.java:580)
01-03 19:41:01.678: E/AndroidRuntime(499):  at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:214)
01-03 19:41:01.678: E/AndroidRuntime(499):  at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:41)
01-03 19:41:01.678: E/AndroidRuntime(499):  at android.database.CursorWrapper.getString(CursorWrapper.java:135)
01-03 19:41:01.678: E/AndroidRuntime(499):  at com.flannigan.musercise.MuserciseActivity$3.onClick(MuserciseActivity.java:133)
01-03 19:41:01.678: E/AndroidRuntime(499):  at android.view.View.performClick(View.java:2408)
01-03 19:41:01.678: E/AndroidRuntime(499):  at android.view.View$PerformClick.run(View.java:8816)
01-03 19:41:01.678: E/AndroidRuntime(499):  at android.os.Handler.handleCallback(Handler.java:587)
01-03 19:41:01.678: E/AndroidRuntime(499):  at android.os.Handler.dispatchMessage(Handler.java:92)
01-03 19:41:01.678: E/AndroidRuntime(499):  at android.os.Looper.loop(Looper.java:123)
01-03 19:41:01.678: E/AndroidRuntime(499):  at android.app.ActivityThread.main(ActivityThread.java:4627)
01-03 19:41:01.678: E/AndroidRuntime(499):  at java.lang.reflect.Method.invokeNative(Native Method)
01-03 19:41:01.678: E/AndroidRuntime(499):  at java.lang.reflect.Method.invoke(Method.java:521)
01-03 19:41:01.678: E/AndroidRuntime(499):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
01-03 19:41:01.678: E/AndroidRuntime(499):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
01-03 19:41:01.678: E/AndroidRuntime(499):  at dalvik.system.NativeStart.main(Native Method)
4

2 回答 2

1

你得到这个error：

android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0

这意味着您cursor size是 0 并且您正在尝试从中获取数据index 0，这会变成force close.

这条线，

String filename = musiccursor.getString(music_column_index);

尝试用这种方式覆盖，

if(music_column_index > 0)
   String filename = musiccursor.getString(music_column_index);
else
   // Toast some error message

谢谢。

于 2013-01-04T04:12:25.500 回答
1

不要简单地moveToPosition()在 cursor 上，确保 cursor可以到那个位置。

对游标使用附加检查，即游标不为空，moveToFirst()为真，并且行数位于您提供给的任何索引之间moveToPosition()。

if( cur != null && cur.getCount() > 0){
  int rnd = //--some random number--

  //--clamp rnd to cursor size--
  rand = Math.max(0,Math.min(cur.getCount() - 1,rnd)); 

  if(cur.moveToPosition(rnd)){
    //--do stuff--
  }

}

除此之外，不要通过列索引获取值，而是重用定义的列名：

musiccursor.getString(musiccursor.getColumnIndex(MediaStore.Audio.Media.DATA));

如果它在投影中，那么它将在带有数据的结果游标中。

于 2013-01-04T04:20:04.720 回答