片段查看返回空

Question

即使我已將視圖設置爲全局變量並在onCreateView（）上調用findViewById，我的視圖仍然返回null。

這是我的視圖部分

public class MainMenu extends Fragment { 
TextView txt = null; 
View view1; 
View mView; 


public View onCreateView(LayoutInflater inflater,ViewGroup container, Bundle savedInstanceState) { 
    // view1 = inflater.inflate(R.layout.fragment_main_menu, container, false); 
    mView = LayoutInflater.from(getActivity()).inflate(R.layout.fragment_main_menu, null,false); 
    pref = getActivity().getPreferences(0); 
    twitter = new TwitterFactory().getInstance(); 
    twitter.setOAuthConsumer(pref.getString("CONSUMER_KEY", ""), pref.getString("CONSUMER_SECRET", "")); 
    txt = (TextView)mView.findViewById(R.id.tww1); 


    //run retrieve tweets method 
    new TweetStream().execute(); 

    new Thread(new MainMenu().new Consumer()).start(); 

    return mView; 
} 

碼以我fragment_main_menu.xml

<LinearLayout 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" 
      android:orientation="vertical"> 

      <TextView 
       android:layout_width="fill_parent" 
       android:layout_height="wrap_content" 
       android:id="@+id/tww1" 
       android:gravity="center" 
       android:textSize="100dp" 
       android:text="OFF"/> 

     </LinearLayout> 

並調用它的代碼：

public void turnOn(){ 
txt.setText("ON"); 
} 

它運行的方法開啓功能：

class Consumer implements Runnable { 

    @Override 
    public void run() { 
     try { 

      while (queue.size() != 0) { 
       String msg = getObj.getMsg(); 
       String[] result = msg.split("\\s"); 
       String msg2 = result[0]; 
       if(msg2.equals("ON")){ 
        txt.setText("ON"); 
        //turnOn(); 
       } 
       else if(msg.equals("OFF")){ 
        txt.setText("OFF"); 
        // turnOff(); 
       } 

      } 
      if (queue.size() == 0) { 
       Thread.sleep(1000); 
       run(); 
      } 


     } catch (InterruptedException e) { 
      e.printStackTrace(); 
     } 
    } 
} 

，這是錯誤我得到：

06-19 12:47:43.921 5213-9586/? E/AndroidRuntime﹕ FATAL EXCEPTION: Thread-128222 
Process: com.example.john.fabric, PID: 5213 
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference 

任何想法？謝謝！

編輯1：我使用虛假的inflater膨脹方法。我不明白爲什麼我應該得到一個空指針。

Edit2：運行turnOn或setText方法裏面都返回null。

Answer 1

使用runonUi線程更新值UI部分試試下面的代碼

@Override 
    public void run() { 
     try { 

      while (queue.size() != 0) { 
       String msg = getObj.getMsg(); 
       String[] result = msg.split("\\s"); 
       String msg2 = result[0]; 

      runOnUiThread(new Runnable() { 

       @Override 
       public void run() { 
       if(msg2.equals("ON")){ 
        txt.setText("ON"); 
        //turnOn(); 
       } 
       else if(msg.equals("OFF")){ 
        txt.setText("OFF"); 
        // turnOff(); 
       } 
       } 
      } 
      } 
      if (queue.size() == 0) { 
       Thread.sleep(1000); 
       run(); 
      } 


     } catch (InterruptedException e) { 
      e.printStackTrace(); 
     } 

Answer 2

使用此膨脹佈局，然後檢查

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
    view1 = inflater.inflate(R.layout.fragment_main_menu, container, false); 
    txt = (TextView) view1.findViewById(R.id.tww1); 
    new Thread(new Consumer()).start(); 
    return view1; 
} 

class Consumer implements Runnable { 

    @Override 
    public void run() { 
     try { 

      while (queue.size() != 0) { 
       String msg = getObj.getMsg(); 
       String[] result = msg.split("\\s"); 
       String msg2 = result[0]; 
       if (msg2.equals("ON")) { 
        turnOn(); 
       } else{ 
        txt.setText("OFF"); 
        // turnOff(); 
       } 

      } 
      if (queue.size() == 0) { 
       Thread.sleep(1000); 
       run(); 
      } 


     } catch (InterruptedException e) { 
      e.printStackTrace(); 
     } 
    } 
} 
public void turnOn(){ 
    txt.setText("ON"); 
}