【Fragment, IntentService】在Thread中執行toast

//先宣告
Activity activity;

//當此Fragment被呼叫起來時會執行
@Override
    public void onAttach(Activity activity) {
        if (Log.IS_DEBUG) Log.i(TAG, TAG + " onAttach");
        super.onAttach(activity);
        this.activity = activity;
    }

new Thread() {
    public void run() {
        //在Thread中執行toast
        showToastByRunnable(activity, activity.getResources().getString("invalidCharacter"), Toast.LENGTH_LONG);
    }
}

//自訂showToastByRunnable方法
private void showToastByRunnable(final Context context, final CharSequence text, final int duration)     { 
        Handler handler = new Handler(Looper.getMainLooper()); 
        handler.post(new Runnable() { 
            @Override 
            public void run() { 
                Toast.makeText(context, text, duration).show(); 
            } 
        }); 
    }