使用chrome调试工具,react-devtools总是显示 "waiting for roots to load...to reload the inspector" and a button saying "click here". 我使用的是react-devtools4.0版本 有两个项目,一个项目用的是react16.2.0,另一个项目react16.6.1. 同样的代码在这两个版本都可以运行,但是react-devtools在react16.2.0的脚…
在介绍两种类方法之前,NSObject Class Reference里对这两个方法说明: +(void)initialize The runtime sends initialize to each class in a program exactly one time just before the class, or any class that inherits from it, is sent its first message from within the program. (Th…