新学React 18.2

beta.reactjs.org (opens new window)

1. How to continue learning React (opens new window)
2. Managing State (opens new window)
3. Adding Interactivity (opens new window)
4. built-in-css-support (opens new window)
5. Keeping Components Pure (opens new window) 渲染的时候不能不纯
6. 选择合适的state (opens new window)

React会等待，直到事件处理程序中的所有代码运行完毕后再处理你的状态更新。这就是为什么重新渲染只发生在所有这些setNumber()调用之后。