android沙漏

Question

如何以編程方式在Android應用程序中顯示沙漏？

Answer 1

您可以使用ProgressDialog：

ProgressDialog dialog = new ProgressDialog(this); 
dialog.setMessage("Thinking..."); 
dialog.setIndeterminate(true); 
dialog.setCancelable(false); 
dialog.show(); 

上面的代碼會顯示在您的Activity的頂部下面的對話框：

或者（或另外），您可以顯示一個進度指標在您的Activity的標題欄中。

您need to request this as a feature靠近你Activity的onCreate()方法使用下面的代碼的頂部：

requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS); 

然後打開它這樣的：

setProgressBarIndeterminateVisibility(true); 

，並把它像這樣關閉：

setProgressBarIndeterminateVisibility(false); 

Answer 2

下面是使用的AsyncTask做這件事的一個簡單的例子：

public class MyActivity extends Activity { 

    protected void onCreate(Bundle savedInstanceState) { 

     ... 

     new MyLoadTask(this).execute(); //If you have parameters you can pass them inside execute method 

    } 

    private class MyLoadTask extends AsyncTask <Object,Void,String>{   

     private ProgressDialog dialog; 

     public MyLoadTask(MyActivity act) { 
      dialog = new ProgressDialog(act); 
     }  

     protected void onPreExecute() { 
      dialog.setMessage("Loading..."); 
      dialog.show(); 
     }  

     @Override 
     protected String doInBackground(Object... params) {   
      //Perform your task here.... 
      //Return value ... you can return any Object, I used String in this case 

      try { 
       Thread.sleep(6000); 
      } catch (InterruptedException e) { 
       e.printStackTrace(); 
      } 
      return(new String("test")); 
     } 

     @Override 
     protected void onPostExecute(String str) {   
      //Update your UI here.... Get value from doInBackground .... 
      if (dialog.isShowing()) { 
       dialog.dismiss(); 
      }   
     } 
    }