vejei

`onSizeChanged`只是在大小被改变时调用，不是用来确定大小的，确定大小就是在`onMeasure`里面完成的。`onMeasure`是测量视图的大小的，这个没错，但是它测量大小也就是在确定它的大小，重写时就是根据情况确定（或者叫“测量”）你绘制的内容应该多大。 [官方文档](https://developer.android.com/reference/android/view/View#onSizeChanged(int,%20int,%20int,%20int))： > This is called during layout when the size of this view has changed. If you were just added to the view hierarchy, you're called with the old...