Android Ansichten Handler Code auszuführen

Question

ich sah, dass in AOSP viel Code wie etwas laufen gibt es:

v.post(new Runnable() { 
     @Override 
     public void run() { 
      // Here comes code 
      x += y; 
     } 
    }); 

Was der Vorteil ist, dies zu tun im Vergleich zu einfach nur x += y; tun?

Answer 1

Dieser Lauf wird den Aufruf erhalten, wenn die Ansicht an die Hauptbenutzerschnittstelle Thread angeschlossen ist. Schauen Sie sich die Post-Methode in View Klasse.

/** 
    * <p>Causes the Runnable to be added to the message queue. 
    * The runnable will be run on the user interface thread.</p> 
    * 
    * @param action The Runnable that will be executed. 
    * 
    * @return Returns true if the Runnable was successfully placed in to the 
    *   message queue. Returns false on failure, usually because the 
    *   looper processing the message queue is exiting. 
    * 
    * @see #postDelayed 
    * @see #removeCallbacks 
    */ 
    public boolean post(Runnable action) { 
     final AttachInfo attachInfo = mAttachInfo; 
     if (attachInfo != null) { 
      return attachInfo.mHandler.post(action); 
     } 

     // Postpone the runnable until we know on which thread it needs to run. 
     // Assume that the runnable will be successfully placed after attach. 
     getRunQueue().post(action); 
     return true; 
    }