AsyncTaskをコールバックメソッドから実行するには？

Question

私は、コードを持っている：

private void submitExec() { 

    if (SQLiteDbWrapper.getInstance().getBookCount()==0) { 

     Toast.makeText(this, "A list of books is empty", Toast.LENGTH_LONG).show(); 
     return; 
    } 

    SQLiteDbWrapper.getInstance().makeFacebook(this, this.getApplicationContext()); 
    if (SQLiteDbWrapper.getInstance().getConnector().getFacebook().isSessionValid()) { 
     new SubmitClass().execute(); 
    } 
    else { 

     SessionEvents.AuthListener listener = new SessionEvents.AuthListener() { 

      @Override 
      public void onAuthSucceed() { 
       MyBookDroidActivity.this.executeSubmitClass(); 
      } 

      @Override 
      public void onAuthFail(String error) { 

      } 
     }; 
     SessionEvents.addAuthListener(listener); 
     SQLiteDbWrapper.getInstance().getConnector().login(); 
    } 
} 

private void executeSubmitClass() { 

    new SubmitClass().execute(); 
} 

このコードは、Facebookから認可とAsyncTaskを実行します。しかし、私は常に、ランタイムエラーを取得：

12-13 21:58:41.513: E/AndroidRuntime(31961): Uncaught handler: thread Thread-25 exiting due to uncaught exception 
12-13 21:58:41.523: E/AndroidRuntime(31961): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare() 
12-13 21:58:41.523: E/AndroidRuntime(31961): at android.os.Handler.<init>(Handler.java:121) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at android.app.Dialog.<init>(Dialog.java:105) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at android.app.AlertDialog.<init>(AlertDialog.java:63) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at android.app.ProgressDialog.<init>(ProgressDialog.java:80) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at android.app.ProgressDialog.<init>(ProgressDialog.java:76) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at com.nda.mybookdroid.MyBookDroidActivity$SubmitClass.onPreExecute(MyBookDroidActivity.java:115) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at android.os.AsyncTask.execute(AsyncTask.java:391) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at com.nda.mybookdroid.MyBookDroidActivity.executeSubmitClass(MyBookDroidActivity.java:101) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at com.nda.mybookdroid.MyBookDroidActivity.access$0(MyBookDroidActivity.java:99) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at com.nda.mybookdroid.MyBookDroidActivity$1.onAuthSucceed(MyBookDroidActivity.java:86) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at com.nda.facebook.SessionEvents.onLoginSuccess(SessionEvents.java:78) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at com.nda.facebook.FacebookConnector$IDRequestListener.onComplete(FacebookConnector.java:141) 
12-13 21:58:41.523: E/AndroidRuntime(31961): at com.facebook.android.AsyncFacebookRunner$2.run(AsyncFacebookRunner.java:254) 
12-13 22:01:47.193: E/AndroidRuntime(32216): Uncaught handler: thread Thread-32 exiting due to uncaught exception 
12-13 22:01:47.203: E/AndroidRuntime(32216): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare() 
12-13 22:01:47.203: E/AndroidRuntime(32216): at android.os.Handler.<init>(Handler.java:121) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at android.app.Dialog.<init>(Dialog.java:105) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at android.app.AlertDialog.<init>(AlertDialog.java:63) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at android.app.ProgressDialog.<init>(ProgressDialog.java:80) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at android.app.ProgressDialog.<init>(ProgressDialog.java:76) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at com.nda.mybookdroid.MyBookDroidActivity$SubmitClass.onPreExecute(MyBookDroidActivity.java:115) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at android.os.AsyncTask.execute(AsyncTask.java:391) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at com.nda.mybookdroid.MyBookDroidActivity.executeSubmitClass(MyBookDroidActivity.java:101) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at com.nda.mybookdroid.MyBookDroidActivity.access$0(MyBookDroidActivity.java:99) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at com.nda.mybookdroid.MyBookDroidActivity$1.onAuthSucceed(MyBookDroidActivity.java:86) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at com.nda.facebook.SessionEvents.onLoginSuccess(SessionEvents.java:78) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at com.nda.facebook.FacebookConnector$IDRequestListener.onComplete(FacebookConnector.java:141) 
12-13 22:01:47.203: E/AndroidRuntime(32216): at com.facebook.android.AsyncFacebookRunner$2.run(AsyncFacebookRunner.java:254) 

私はLooper.prepare（）を実行しようとするが、この場合には、アプリケーションが常にフリーズ。 AsyncTaskをどのように実行すればよいですか？ありがとうございました。

Answer 1

UIスレッドからAsyncTaskを実行する必要があります。次のようなことができます：

private void executeSubmitClass() { 
    runOnUiThread(new Runnable() { 
     @Override 
     public void run() { 
      new SubmitClass().execute(); 
     } 
    }); 
} 

Answer 2

メイン（UI）スレッドでasyncTask.execute()に電話する必要があります。