在组件材质UI ReactJS中显示数据列表

Question

我正在尝试使用redux和材质ui显示电影列表。

FilmsService：

export const FilmServices = {
    getAllFilms,

};


function getAllFilms(){
    return axios.get(config.baseUrl).then((response)=>{
        return response;
    }).catch((err)=>{
        console.log(err);
    })
}

FilmAction：

export function getAllFilms() {
    return dispatch => {
        FilmServices.getAllFilms()
            .then((response) => {
                if (response) {
                    dispatch(GET_FILMS(response));
                }
            })
    }
}

FilmReducer：

   const initialState = { films: [] }
export function filmreducer(state = initialState, action) {
    switch (action.type) {
        case 'GET_FILMS':
            console.log(action);
            return{
                ...state,
                films : action.payload.data

            };
        case 'GET_FILMS_BY_NAME':
            return{
                ...state,
                films : action.payload.data

            };
        default:
            return state
    }
}

这是我的组件：

import React , { Component }from 'react';
import PropTypes from 'prop-types';
import {makeStyles, withStyles} from '@material-ui/core/styles';
import {getAllFilms} from "../store/actions/FilmActions";
import Button from '@material-ui/core/Button';
import Card from "@material-ui/core/Card/Card";
import CardActionArea from "@material-ui/core/CardActionArea/CardActionArea";
import CardMedia from "@material-ui/core/CardMedia/CardMedia";
import CardContent from "@material-ui/core/CardContent/CardContent";
import Typography from "@material-ui/core/Typography/Typography";
import CardActions from "@material-ui/core/CardActions/CardActions";
import connect from "react-redux/es/connect/connect";
import { withRouter } from 'react-router-dom';

const useStyles = makeStyles({
    card: {
        maxWidth: 345,
    },
});

class FilmsCard extends Component {


    componentDidMount () {
        const {dispatch} = this.props;
        dispatch(getAllFilms());
    }

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

    render() {
        const films = this.props.films || [];
        return (
            <Card>
                {films.map(film => {
                    return(
                    <CardActionArea>
                        <CardMedia
                            component="img"
                            alt="Contemplative Reptile"
                            height="140"
                            image="/static/images/cards/contemplative-reptile.jpg"
                            title="Contemplative Reptile"
                        />
                        <CardContent>
                            <Typography gutterBottom variant="h5" component="h2">
                                {film.show ? film.show.name : film.name}
                            </Typography>
                            <Typography variant="body2" color="textSecondary" component="p">
                                {film.show ? film.show.name : film.name}
                            </Typography>
                        </CardContent>
                    </CardActionArea>
                        )})}
                <CardActions>
                    <Button size="small" color="primary">
                        Share
                    </Button>
                    <Button size="small" color="primary">
                        Learn More
                    </Button>
                </CardActions>
            </Card>
        );
    }
}

FilmsCard.propTypes = {
    classes: PropTypes.object.isRequired,
};

const mapStateToProps = (state) => {
    return {
        films : state.filmreducer
    };
}
const connectedVendorPage = withRouter(connect(mapStateToProps, null, null, {
    pure: false
})(withStyles(useStyles)(FilmsCard)));
export { connectedVendorPage as FilmsCard };

当我跑步时出现此错误：

TypeError：无法读取未定义的属性'length'

我认为材料ui有问题，因为当我在一个简单的组件中尝试此代码（没有材料ui时，我不会收到错误。）>

有人可以帮我吗？谢谢

我正在尝试使用redux和材质ui显示电影列表。 FilmsService：导出const FilmServices = {getAllFilms，};函数getAllFilms（）{返回axios.get（config.baseUrl）.then（（...

Answer 1

@ Muhammad Awais我有这样的changer我的render（），它的工作：：>

render() {
    const { classes } = this.props;
    const { films } = this.props.films;

    return (
        <Card className={classes.card}>
            {films.map(film => {
                return(
                    <CardActionArea>
                        <CardMedia
                            className={classes.media}
                            component="img"
                            alt="Contemplative Reptile"
                            height="140"
                            image="http://static.tvmaze.com/uploads/images/medium_portrait/168/421041.jpg"
                            title="Contemplative Reptile"
                        />
                        <CardContent>
                            <Typography gutterBottom variant="h5" component="h2">
                                {film.show ? film.show.name : film.name}
                            </Typography>
                            <Typography variant="body2" color="textSecondary" component="p">
                                {film.show ? film.show.name : film.name}
                            </Typography>
                        </CardContent>
                    </CardActionArea>
                )})}
            <CardActions>
                <Button size="small" color="primary">
                    Share
                </Button>
                <Button size="small" color="primary">
                    Learn More
                </Button>
            </CardActions>
        </Card>
    );
}

Answer 2

在render（）方法中，删除此行const { films } = this.props.films;，然后尝试以下操作：const films = this.props.films || [];并且，请在构造函数中删除console.log(this.props.films)。使用以下方法更新FilmAction：

Answer 3

也通过更改这部分代码为我工作：

Answer 4

在您的渲染功能中执行类似const {films} = this.props;的操作>