處理器postDelayed無法更新UI

Question

好傢伙我試圖更新在短暫的延遲之後的UI，爲此我使用的處理器的postdelayed方法。以下代碼最初將我的textview文本設置爲「Processing」，並且包含在處理程序的runnable中的代碼得到執行，但不會更新UI？請注意，這是在做片段

TextView progressText=(TextView)parent.findViewById(R.id.inProgressText); 
progressText.setText("Processing"); 

getActivity().getMainLooper()).postDelayed(new Runnable() { 
    @Override 
    public void run() { 
     TextView progressText=(TextView)parent.findViewById(R.id.inProgressText); 
     progressText.setText("Request completed");    
    } 
}, 3000); 

感謝您的幫助

Answer 1

使用此代碼

public class MainActivity extends Activity { 
TextView progressText = null; 

public View onCreateView(LayoutInflater inflater, ViewGroup container, 
    Bundle savedInstanceState) { 

    View rootView = inflater.inflate(R.layout.activity_main, container, false); 

    progressText = (TextView) rootView.findViewById(R.id.inProgressText); 
    progressText.setText("Processing"); 
    progressText.postDelayed(new Runnable() { 
     @Override 
     public void run() { 
      progressText.setText("Request completed"); 
     } 
    }, 3000); 
     return rootView; 
} 
} 

Answer 2

變化

getActivity().getMainLooper()).postDelayed(new Runnable() 

到：

final Handler handler = new Handler(); 

然後

handler.postDelayed(new Runnable() { 
    @Override 
    public void run() { 
     final TextView progressText=(TextView)findViewById(R.id.inProgressText); 
     progressText.setText("Request completed");    
    } 
}, 3000); 

Answer 3

請嘗試是這樣的：我在Fragement檢查，它可以正常使用。

View parent= inflater.inflate(R.layout.your_fragement, container, false); 
TextView progressText=(TextView)parent.findViewById(R.id.inProgressText); 
progressText.setText("Processing"); 

      progressText.postDelayed(new Runnable() { 
       @Override 
       public void run() { 
        progressText.setText("Request completed"); 
       } 
      }, 3000);