如果你使用RxJava & RxBindings，一行。类似的方法没有样板。这也解决了蒂姆·奥廷(Tim Autin)的回答中隐藏警告的问题。

RxView.layoutChanges(yourView).take(1)
      .subscribe(aVoid -> {
           // width and height have been calculated here
      });

就是它了。不需要取消订阅，即使从未调用。

public final class ViewUtils {

    public interface ViewUtilsListener {
        void onDrawCompleted();
    }

    private ViewUtils() {
    }

    public static void onDraw(View view, ViewUtilsListener listener) {
        view.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                if (view.getHeight() != 0 && view.getWidth() != 0) {
                    if (listener != null) {
                        listener.onDrawCompleted();
                    }
                    view.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                }
            }
        });
    }
}

你可以这样用;

ViewUtils.onDraw(view, new ViewUtils.ViewUtilsListener() {
                @Override
                public void onDrawCompleted() {
                    int width = view.getWidth();
                    int height = view.getHeight();
                }
            });

你调用getWidth()太早了。UI还没有在屏幕上调整大小和布局。

无论如何，我怀疑您是否想要做您正在做的事情——动画小部件不会改变它们的可点击区域，因此无论它如何旋转，按钮仍然会对原始方向的点击做出响应。

也就是说，您可以使用维度资源来定义按钮大小，然后从布局文件和源代码中引用该维度资源，以避免此问题。

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)
        }
    }
}

正如Ian在这篇Android开发者文章中所述:

Anyhow, the deal is that layout of the contents of a window happens after all the elements are constructed and added to their parent views. It has to be this way, because until you know what components a View contains, and what they contain, and so on, there's no sensible way you can lay it out. Bottom line, if you call getWidth() etc. in a constructor, it will return zero. The procedure is to create all your view elements in the constructor, then wait for your View's onSizeChanged() method to be called -- that's when you first find out your real size, so that's when you set up the sizes of your GUI elements. Be aware too that onSizeChanged() is sometimes called with parameters of zero -- check for this case, and return immediately (so you don't get a divide by zero when calculating your layout, etc.). Some time later it will be called with the real values.

我们需要等待绘制视图。为此，请使用OnPreDrawListener。芬兰湾的科特林的例子:

val preDrawListener = object : ViewTreeObserver.OnPreDrawListener {

                override fun onPreDraw(): Boolean {
                    view.viewTreeObserver.removeOnPreDrawListener(this)

                    // code which requires view size parameters

                    return true
                }
            }

            view.viewTreeObserver.addOnPreDrawListener(preDrawListener)