【Android】获取控件的宽和高

      有时候我们须要在Activity的时候获取控件的宽和高来做一些操作，以下介绍三种获取宽和高的方式：

1. onWindowFocusChanged

@Override
    public void onWindowFocusChanged(boolean hasFocus)
    {
        super.onWindowFocusChanged(hasFocus);
        if (hasFocus)
        {
            int width = image.getMeasuredWidth();
            int height = image.getMeasuredHeight();
            Toast.makeText(MainActivity.this, "width = " + width + "---height = " + height, Toast.LENGTH_SHORT).show();
        }

    }

2. post方式

 @Override
    protected void onStart()
    {
        super.onStart();

        image.post(new Runnable()
        {

            @Override
            public void run()
            {
                int width = image.getMeasuredWidth();
                int height = image.getMeasuredHeight();
                Toast.makeText(MainActivity.this, "onstart--width = " + width + "---height = " + height, Toast.LENGTH_SHORT).show();
            }
        });
    }

3. ViewTreeObserver

 ViewTreeObserver observer = image.getViewTreeObserver();
        observer.addOnGlobalLayoutListener(new OnGlobalLayoutListener()
        {

            @Override
            public void onGlobalLayout()
            {
                image.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                int width = image.getMeasuredWidth();
                int height = image.getMeasuredHeight();
                Toast.makeText(MainActivity.this, "onglobal--width = " + width + "---height = " + height, Toast.LENGTH_SHORT).show();
            }
        });

备注：以上image是ImageView控件

ImageView image = (ImageView)findViewById(R.id.image);