Android 初学------获取View的宽高 坐标 边距

btn = (Button) findViewById(R.id.show);
ViewTreeObserver vto = btn.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
btn.getViewTreeObserver().removeGlobalOnLayoutListener(this);
System.out.println("width:"+btn.getWidth()+",height:"+btn.getHeight());
if(Build.VERSION.SDK_INT>=11){
System.out.println("x:"+btn.getX()+",y:"+btn.getY());
RelativeLayout.LayoutParams  ly=(android.widget.RelativeLayout.LayoutParams) btn.getLayoutParams();
System.out.println("paddingleft:"+ly.leftMargin);
}else{
//获取xy坐标
}
}
});