在框架佈局中顯示imageview背後的進度對話框

Question

我想顯示一個異步任務的前五秒圖像，然後顯示進度對話框。

是否可以在前5秒後在圖像視圖後顯示進度對話框，然後隱藏該圖像視圖並顯示進度對話框？

Answer 1

通過應用Rajen Raiyarela的建議下，我做了這個：

protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_act1); 

    pb = (ProgressBar) findViewById(R.id.pb); 
    iv = (ImageView) findViewById(R.id.iv); 
    TimerTask task = new TimerTask() { 
     @Override 
     public void run() { 
      runOnUiThread(new Runnable() { 
       @Override 
       public void run() { 
        swapVisibility(); 
       } 
      }); 
     } 
    }; 
    timer = new Timer(); 
    timer.schedule(task, 5000); 

    new Task().execute(); 
} 

class Task extends AsyncTask<Void, Void, Void> { 

    @Override 
    protected Void doInBackground(Void... voids) { 
     try { 
      Thread.sleep(7000); // imitating heavy operation 
     } catch (InterruptedException e) { 
      e.printStackTrace(); 
     } 
     return null; 
    } 

    @Override 
    protected void onPostExecute(Void aVoid) { 
     super.onPostExecute(aVoid); 
     timer.cancel(); 
     if (pb.getVisibility() != View.VISIBLE) 
      swapVisibility(); 
    } 
} 

private void swapVisibility() { 
    pb.setVisibility(View.VISIBLE); 
    iv.setVisibility(View.GONE); 
    Log.e("TAG", "Visibility changed"); 
}