最近一直在做react项目，发现一个bug，困扰了我两天。
Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in the componentWillUnmount method.
稍稍翻译下：不能在已经被销毁的组件中调用setState()方案
出现场景：跳转路由 当前组件被销毁 组件内部还存在异步操作对state的状态信息 比如http请求,定时器setTimeOut更新state
解决方法：
componentWillUnmount() {
this.setState = (state,callback)=>{ return; };
}
组件被销毁之前重写setState方法 不对状态做任何改变