onCreate中获得控件的大小

@Override 
  public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.main); 
      final ImageView imageView = (ImageView) findViewById(R.id.imageview);       
      int w = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED); 
      int h = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED); 
      imageView.measure(w, h); 
      int height =imageView.getMeasuredHeight();
      int width =imageView.getMeasuredWidth();
      textView.append("
"+height+","+width);
      System.out.println("执行完毕.."+System.currentTimeMillis()); 
  }
//------------------------------------------------方法一 
int w = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED); 
int h = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED); 
imageView.measure(w, h); 
int height =imageView.getMeasuredHeight(); 
int width =imageView.getMeasuredWidth(); 
textView.append("
"+height+","+width); 
//-----------------------------------------------方法二 
ViewTreeObserver vto = imageView.getViewTreeObserver(); 
vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() { 
    public boolean onPreDraw() { 
        int height = imageView.getMeasuredHeight(); 
        int width = imageView.getMeasuredWidth(); 
        textView.append("
"+height+","+width); 
        return true; 
    } 
}); 
//-----------------------------------------------方法三    
ViewTreeObserver vto2 = imageView.getViewTreeObserver();   
vto2.addOnGlobalLayoutListener(new OnGlobalLayoutListener() { 
    @Override   
    public void onGlobalLayout() { 
        imageView.getViewTreeObserver().removeGlobalOnLayoutListener(this);   
        textView.append("

"+imageView.getHeight()+","+imageView.getWidth()); 
    }   
});