音頻錄製出現異常

Question

我正在創建一個錄製應用程序。我需要錄製音頻並將其存儲在SD卡中。但是，當我嘗試運行它運行良好的應用程序，但是當我按下停止按鈕，它顯示消息「不幸的是你的應用程序已經停止」
這裏是logcat的

enter code here 
08-01 12:09:18.331: E/SoundRecordingActivity(5611): sdcard access error 
08-01 12:09:21.043: D/AndroidRuntime(5611): Shutting down VM 
08-01 12:09:21.043: W/dalvikvm(5611): threadid=1: thread exiting with uncaught exception (group=0x2c3381f8) 
08-01 12:09:21.043: E/AndroidRuntime(5611): FATAL EXCEPTION: main 
08-01 12:09:21.043: E/AndroidRuntime(5611): java.lang.NullPointerException 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at com.blitze.recordingapp.SoundRecordingActivity$2.onClick(SoundRecordingActivity.java:110) 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at android.view.View.performClick(View.java:3511) 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at android.view.View$PerformClick.run(View.java:14115) 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at android.os.Handler.handleCallback(Handler.java:605) 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at android.os.Handler.dispatchMessage(Handler.java:92) 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at android.os.Looper.loop(Looper.java:137) 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at android.app.ActivityThread.main(ActivityThread.java:4424) 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at java.lang.reflect.Method.invokeNative(Native Method) 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at java.lang.reflect.Method.invoke(Method.java:511) 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
08-01 12:09:21.043: E/AndroidRuntime(5611):  at dalvik.system.NativeStart.main(Native Method) 
08-01 12:09:23.759: W/System.err(5611): java.lang.Throwable: stack dump 
08-01 12:09:23.759: W/System.err(5611):  at java.lang.Thread.dumpStack(Thread.java:496) 
08-01 12:09:23.759: W/System.err(5611):  at android.os.Process.killProcess(Process.java:725) 
08-01 12:09:23.759: W/System.err(5611):  at com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:82) 
08-01 12:09:23.759: W/System.err(5611):  at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:693) 
08-01 12:09:23.759: W/System.err(5611):  at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:690) 
08-01 12:09:23.759: W/System.err(5611):  at dalvik.system.NativeStart.main(Native Method) 

這裏是我的代碼

startButton.setOnClickListener(new View.OnClickListener() { 

     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      startButton.setEnabled(false); 
      stopButton.setEnabled(true); 

      File sampleDir = Environment.getExternalStorageDirectory(); 
      try { 
       audiofile = File.createTempFile("sound", ".3gp", sampleDir); 

      recorder = new MediaRecorder(); 
      recorder.setAudioSource(MediaRecorder.AudioSource.MIC); 
      recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP); 
      recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); 
      recorder.setOutputFile(audiofile.getAbsolutePath()); 
      recorder.prepare(); 
      recorder.start(); 




      } catch (IOException e) { 
       Log.e(TAG, "sdcard access error"); 
       return; 
      } 



     } 
    }); 
    stopButton.setOnClickListener(new View.OnClickListener() { 

     public void onClick(View v) { 
      startButton.setEnabled(true); 
      stopButton.setEnabled(false); 
      recorder.stop(); 
      recorder.release(); 

      //counter.cancel(); 
      addRecordingToMediaLibrary(); 

     } 
    }); 

protected void addRecordingToMediaLibrary() { 
    ContentValues values = new ContentValues(4); 
    long current = System.currentTimeMillis(); 
    values.put(MediaStore.Audio.Media.TITLE, "audio" + audiofile.getName()); 
    values.put(MediaStore.Audio.Media.DATE_ADDED, (int) (current/1000)); 
    values.put(MediaStore.Audio.Media.MIME_TYPE, "audio/3gpp"); 
    values.put(MediaStore.Audio.Media.DATA, audiofile.getAbsolutePath()); 
    ContentResolver contentResolver = getContentResolver(); 

    Uri base = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI; 
    Uri newUri = contentResolver.insert(base, values); 

    sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, newUri)); 
    Toast.makeText(this, "Added File " + newUri, Toast.LENGTH_LONG).show(); 
} 

}

我將SD卡連接到手機。 我不明白是什麼問題。給我任何提示或參考。
謝謝。

Answer 1

你需要看看行號110這是在你的OnClick功能的線。您將引用諸如「recorder.stop（）」之類的東西，並且錄音機此時將爲NULL。

看起來您需要將您在啓動函數中創建的記錄器對象的實例傳遞給停止函數。