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("\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());

    }

});