在onCreate获取视图的大小的三种方法

Home / Android MrLee 2015-3-6 3189

某些自定义动画或者控件有时候需要动态添加到布局中,而oncreate初始的时候,整体的layout还并未开始计算,在onlayout之后才有大小,那么怎么在onCreate中获取控件视图的大小呢,那么方法如下:
@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("\n"+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("\n"+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("\n"+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("\n\n"+imageView.getHeight()+","+imageView.getWidth()); 
    }   
});     

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