警告：无法在卸载的组件上调用setState（或forceUpdate） [英] Warning: Can't call setState (or forceUpdate) on an unmounted component

问题描述

每次登录时都会收到此警告，

I am getting this warning every time I sign in,

警告：无法在已卸载的情况下调用setState（或forceUpdate）
组件。这是一个无操作，但它表示
应用程序中存在内存泄漏。要修复，请取消componentWillUnmount方法中的所有订阅和异步任务
。

Warning: Can't call setState (or forceUpdate) 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.

这是我的代码：

authpage.js

authpage.js

 handleLoginSubmit = (e) => {
    e.preventDefault()
    let { email,password } = this.state
    const data = {
      email : email,
      password : password
    }
    fetch('http://localhost:3001/auth/login',{
      method : 'post',
      body : JSON.stringify(data),
      headers : {
        "Content-Type":"application/json"
      }
    }).then(res => res.json())
    .then(data => {
      if(data.success){
        sessionStorage.setItem('userid',data.user.id)
        sessionStorage.setItem('email',data.user.email)
      }
      this.setState({loginData : data,
                     userData : data,
                     email:"",
                     password:""})
      if(data.token) {
        Auth.authenticateUser(data.token)
        this.props.history.push('/dashboard')
      }
      this.handleLoginMessage()
      this.isUserAuthenticated()
    })
  }

export default withRouter(AuthPage)

使用 withRouter 所以我可以访问用于导航的道具 this.props.history.push（'/ dashboard'）
如果我没有使用withRouter我无法访问this.props

use withRouter so I can access props which I use to navigate this.props.history.push('/dashboard') if I didn't use withRouter I cannot access this.props

index.js

const PrivateRoute = ({ component : Component, ...rest }) => {
  return (
    <Route {...rest} render = { props => (
    Auth.isUserAuthenticated() ? (
      <Component {...props} {...rest} />
    ) : (
      <Redirect to = {{
        pathname: '/',
        state: { from: props.location }
      }}/>
    )
  )}/>
  )
}

const PropsRoute = ({ component : Component, ...rest }) => (
  <Route {...rest} render = { props => (
    <Component {...props} {...rest} />
  )}/>
)

const Root = () => (
  <BrowserRouter>
    <Switch>
      <PropsRoute exact path = "/" component = { AuthPage } />
      <PrivateRoute path = "/dashboard" component = { DashboardPage } />
      <Route path = "/logout" component = { LogoutFunction } />
      <Route component = { () => <h1> Page Not Found </h1> } />
    </Switch>
  </BrowserRouter>
)

我认为问题在于我的withRouter，
如何在不使用withRouter的情况下访问this.props？

I think the problem is with my withRouter, how can we access this.props without using withRouter ?

推荐答案

它是异步所以

this.setState({
   loginData : data,
   userData : data,
   email:"",
   password:""
})

make error
您可以使用 this._mount 检查组件是否已挂载

make error You can use this._mount to check component is mounted or unmount

componentDidMount () {
   this._mounted = true
}
componentWillUnmount () {
   this._mounted = false
}
...
if(this._mounted) {
    this.setState({
        loginData : data,
        userData : data,
        email:"",
        password:""
})
...

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