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如何在react中的unmount组件中设置state

reactjs javascript

Thuan Nguyen · 技术社区 · 7 年前

componentDidMount

我的问题是警告反应通知:

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.
in DiscoverPage (created by Route)

DiscoverPage 组件:

import React, { Component } from 'react';
import { Switch, Route, Redirect } from 'react-router-dom';
import TvShows from './TvShows';
import Movies from './Movies';
import MovieDetail from "../MoviePage/MovieDetail";
import TvDetail from "../TvShowPage/TvDetail";

class DiscoverPage extends Component {

constructor(props) {
    super(props);
    this.state = {
        data: {}
    }
}

getDataItem = (data) => {
    this.setState({ data: data });
};

render() {
    return (
        <Switch>
            <Route exact path="/discover/movie" render={props => <Movies data={this.getDataItem} {...props} />} />
            <Route path="/discover/tv" render={props => <TvShows data={this.getDataItem} {...props} />} />
            <Route path="/movie/:movie" render={props => <MovieDetail data={this.state.data} {...props} />} />
            <Route path="/tv/:tv" render={props => <TvDetail data={this.state.data} {...props} />} />
            <Redirect to="/discover/movie" />
        </Switch>
    );
}
}

export default DiscoverPage;

Movies

import React, { Component } from 'react';
import requestApi from '../api';
import MovieList from "../MoviePage/MovieList";

class Movies extends Component {

constructor(props) {
    super(props);
    this.state = {
        data: {
            page: 1,
            results: []
        }
    }
}

componentDidMount() {
    requestApi.fetchData('discover', 'movie').then(response => {
        this.setState({ data: response.data, isLoading: false });
    });
}

getMoviebyId = (id) => {
    requestApi.fetchDataById('movie', id).then(response => {
        this.props.data(response.data);
    });
};

nextPage = (e) => {
    const page = this.state.data.page + 1;
    requestApi.fetchDataPaginate('discover', 'movie', page).then(response => {
        this.setState({data: response.data});
    });
};
prevPaginate = (e) => {
    const page = this.state.data.page - 1;
    requestApi.fetchDataPaginate('discover', 'movie', page).then(response => {
        this.setState({ data: response.data });
    });
};

render() {
    return (
        <div className="container">
            <div className="ss_media">
                <h2 className="title">Discover New Movies & TV Shows</h2>
                <MovieList
                    movie={this.getMoviebyId}
                    routeProps={this.props}
                    prevPaginate={this.prevPaginate}
                    nextPaginate={this.nextPage}
                    moviesList={this.state.data} />
            </div>
        </div>
    );
}
}

export default Movies;

5 回复 | 直到 7 年前

cosh 7 年前

setState 在未安装的组件上,即当前未呈现的组件上。最有可能的是,您的其他组件之一( Movies TvShows data 支柱。当呈现其中一个组件时, DiscoveryPage getDataItem 通过道具将导致的未呈现时要调用的方法。为了解决这个问题(假设您要做的是将数据从一个组件传递到另一个组件),我建议您可以使用 localStorage

设置状态 component... componentWillUnmount

编辑: Movie 本地存储 getMovieById 方法,而不是:

getMoviebyId = (id) => {
    requestApi.fetchDataById('movie', id).then(response => {
        //this next sentence will call DiscoveryPage's setState
        //DiscoveryPage is not mounted, so a warning will be raised
        this.props.data(response.data);
    });
};

getMoviebyId = (id) => {
    requestApi.fetchDataById('movie', id).then(response => {
        //any component can access this store
        localStorage.setItem("data", response.data);
    });
};

localStorage.getItem("data");

您的代码有点混乱。我很难理解你在哪里使用的 数据

,管理它是一个很好的做法,我的意思是打电话来 localStorage.removeItem("data") 组件将卸载

Anu Zedorg 7 年前

react-router render methods

<Route path="/user/:username" component={User}/>

jadlmir 7 年前

import React, { Component } from 'react';
import { Switch, Route, Redirect } from 'react-router-dom';
import TvShows from './TvShows';
import Movies from './Movies';
import MovieDetail from '../MoviePage/MovieDetail';
import TvDetail from '../TvShowPage/TvDetail';

class DiscoverPage extends Component {
    constructor(props) {
        super(props);
        this.state = {
            data: {}
        };
    }
    getALLDATA() {
        //update your state after your request
        request().then(res => {
            this.setState({
                data: res.data
            });
        });
    }
    componentDidMount() {
        this.getALLDATA();
    }
    getDataItem = () => {
        return this.state.data;
    };

    render() {
        return (
            <Switch>
                <Route exact path="/discover/movie" render={props => <Movies data={this.getDataItem} {...props} />} />
                <Route path="/discover/tv" render={props => <TvShows data={this.getDataItem} {...props} />} />
                <Route path="/movie/:movie" render={props => <MovieDetail data={this.state.data} {...props} />} />
                <Route path="/tv/:tv" render={props => <TvDetail data={this.state.data} {...props} />} />
                <Redirect to="/discover/movie" />
            </Switch>
        );
    }
}

export default DiscoverPage;

Damian Peralta 7 年前

react-router-dom

import { Switch, Route, Redirect, BrowserRouter } from 'react-router-dom'; // Add BrowserRouter

class DiscoverPage extends Component {

...
render() {
    return (
    <BrowserRouter> // Add this 
        <Switch>
            <Route exact path="/discover/movie" render={props => <Movies data={this.getDataItem} {...props} />} />
            <Route path="/discover/tv" render={props => <TvShows data={this.getDataItem} {...props} />} />
            <Route path="/movie/:movie" render={props => <MovieDetail data={this.state.data} {...props} />} />
            <Route path="/tv/:tv" render={props => <TvDetail data={this.state.data} {...props} />} />
            <Redirect to="/discover/movie" />
        </Switch>
    </BrowserRouter>
    );
}
}

sametcodes Tetramputechture 7 年前

比如:

componentDidMount(){
    var {state, setState} = this.props;
    setState({doNotRender: true});
}

componentDidUpdate(){
    var {state, setState} = this.props;
    if(!state.doNotRender){ //any_condition ur choice
       setState({doNotRender: true});
    }
}