如何在Android上實現識別器

我的軟件架構如下：
TabActivity是一個TabHost活動。
它包含2個ActivityGroup：AGroup和BGroup。
AGroup包含2個活動：A1Activity和A2Activity。如何在Android上實現識別器

我想在A1Activity中實現識別器。
我的代碼如下：

private static final int VOICE_RECOGNIZER_REQUEST_CODE = 0x1008; 
public void Recognizera() { 
     PackageManager pm = getPackageManager(); 
     List<ResolveInfo> activities = pm.queryIntentActivities(new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH), 0); 

     if(activities.size() != 0) { 
      try { 
       Intent intent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH); 
       intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM); 
       intent.putExtra(RecognizerIntent.EXTRA_PROMPT, "語音辨識"); 
       startActivityForResult(intent, VOICE_RECOGNIZER_REQUEST_CODE); 
      } 
      catch(Exception e) { 
       e.printStackTrace(); 
      } 
     } 
} 
@Override 
protected void onActivityResult(int RequestCode, int ResultCode, Intent data) { 
    switch(RequestCode) { 
    case VOICE_RECOGNIZER_REQUEST_CODE: 
     if(RequestCode == VOICE_RECOGNIZER_REQUEST_CODE && ResultCode == RESULT_OK) { 
      ArrayList<String> results = data.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS); 

      for(int i = 0; i < results.size(); i++) { 
       System.out.println("results " + results.get(i)); 
      } 
     } 
     break; 
    } 
    super.onActivityResult(RequestCode, ResultCode, data); 
}

但它顯示「未知問題」，如下網址的圖片。
enter image description here
但在logcat中沒有任何錯誤消息。
如何修改？