Small knowledge points

1. In ViewGroup, use OnLayout () to get the width and height of the child element, not with the getwidth ()/getheight must use Getmeasurewidth ()/height ()

Explore the art of Android development discover that GetWidth ()/height () is initialized after the OnLayout () method.

2. When ViewGroup uses OnLayout (), the layout () method of the child element is called, and its left,top,right,bottom is relative to the container, not to the screen.

That is, instead of traversing the layout () of the child element, add the position parameter of the parent element.

3. Click event: When Ontouchevent () returns True, the Onintercepter () method will not be called again.

Small knowledge points