https://www.jianshu.com/p/146e5cec4863 Custom View Basics-The most understandable custom View principle series (1)
https://www.jianshu.com/p/1dab927b2f36 Custom View Measure Process-The most understandable custom View principle series (2)
https://www.jianshu.com/p/158736a2549d Custom View Layout Process-The most understandable series of custom View principles (3)
https://www.jianshu.com/p/95afeb7c8335 Custom View Draw Process-The most understandable series of custom View principles (4)