用法:

imageView.size { width, height ->
            //your code
        }

延伸:

fun <T : View> T.size(function: (Int, Int) -> Unit) {
    if (isLaidOut && height != 0 && width != 0) {
        function(width, height)
    } else {
        if (height == 0 || width == 0) {
            var onLayoutChangeListener: View.OnLayoutChangeListener? = null
            var onGlobalLayoutListener: ViewTreeObserver.OnGlobalLayoutListener? = null

            onGlobalLayoutListener = object : ViewTreeObserver.OnGlobalLayoutListener {
                override fun onGlobalLayout() {
                    if (isShown) {
                        removeOnLayoutChangeListener(onLayoutChangeListener)
                        viewTreeObserver.removeOnGlobalLayoutListener(this)
                        function(width, height)
                    }
                }
            }

            onLayoutChangeListener = object : View.OnLayoutChangeListener {
                override fun onLayoutChange(
                    v: View?,
                    left: Int,
                    top: Int,
                    right: Int,
                    bottom: Int,
                    oldLeft: Int,
                    oldTop: Int,
                    oldRight: Int,
                    oldBottom: Int
                ) {
                    val width = v?.width ?: 0
                    val height = v?.height ?: 0
                    if (width > 0 && height > 0) {
                        // remove after finish
                        viewTreeObserver.removeOnGlobalLayoutListener(onGlobalLayoutListener)
                        v?.removeOnLayoutChangeListener(this)
                        function(width, height)
                    }
                }
            }

            viewTreeObserver.addOnGlobalLayoutListener(onGlobalLayoutListener)
            addOnLayoutChangeListener(onLayoutChangeListener)
        } else {
            function(width, height)
        }
    }
}

这是一个有点旧，但我自己有麻烦(需要在一个片段中创建动画对象)。这个解决方案对我来说很有效，我相信这是不言自明的。

class YourFragment: Fragment() {
    var width = 0
    var height = 0


override fun onCreateView(
    inflater: LayoutInflater, container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {
    // Inflate the layout for this fragment
    val root = inflater.inflate(R.layout.fragment_winner_splash, container, false)
    container?.width.let {
        if (it != null) {
            width = it
        }
    }
    container?.height.let {
        if (it != null) {
            height = it
        }
    }
    
    return root
}
 

我宁愿使用OnPreDrawListener()而不是addOnGlobalLayoutListener()，因为它被调用得比其他侦听器早一点。

    view.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener()
    {
        @Override
        public boolean onPreDraw()
        {
            if (view.getViewTreeObserver().isAlive())
                view.getViewTreeObserver().removeOnPreDrawListener(this);
            
            // put your code here
            return true;
        }
    });

根据@Pang的评论调整了代码onPreDraw方法应返回true以继续当前的绘图过程。

我们可以用

@Override
 public void onWindowFocusChanged(boolean hasFocus) {
  super.onWindowFocusChanged(hasFocus);
  //Here you can get the size!
 }

最简洁的方法是使用post method of view:

科特林：

  view.post{
      var width = view.width
      var height = view.height
  }

Java:

view.post(new Runnable() {
    @Override
    public void run() {
        int width = view.getWidth();
        int height = view.getHeight();
    }
});

如果你担心过度工作的onDraw方法，你可以总是设置维度为空在构造过程中，然后只设置onDraw内部的维度，如果它是空的。

这样你就不会在onDraw内部做任何工作

class myView(context:Context,attr:AttributeSet?):View(context,attr){
var height:Float?=null


override fun onDraw(canvas:Canvas){
    if (height==null){height=this.height.toFloat()}
    }
}