23_评论管理_删除

佚名 7年前 (2019-04-17) 随笔 1588人围观抢沙发百度已收录

import React from 'react'
import CommentAdd from '../comment-add/comment-add'
import CommentList from '../comment-list/comment-list'

export default class App extends React.Component {
    // 第一种初始化数据对象方法
    /*    constructor(props) {
            super(props)
            this.state = {
                comments: [
                    {username: 'Tom', content: 'react挺好的！'},
                    {username: 'Jack', content: 'react有点难！'}
                ]
            }
        }*/

    //第二种初始化数据对象方法,给对象指定state属性
    state = {
        comments: [
            {username: 'Tom', content: 'react挺好的！'},
            {username: 'Jack', content: 'react有点难！'},
            {username: 'Jensen', content: '干就完事儿了！'}
        ]
    }
    //添加评论
    addComment = (comment) => {
        //得到状态
        const {comments} = this.state;
        //修改状态内容
        comments.unshift(comment);
        //最后更新状态
        this.setState({comments});
    }
    //删除指定评论
    deleteComment = (index) => {
        const {comments} = this.state
        //  splice可以进行三种操作，增(index,0,{})、删(index,1)、改(index,1,{})
        comments.splice(index, 1);

        //更新状态
        this.setState({comments});
    }

    render() {
        const {comments} = this.state
        return (
            <div>
                <div>
                    <header className="site-header jumbotron">
                        <div className="container">
                            <div className="row">
                                <div className="col-xs-12">
                                    <h1>请发表对React的评论</h1>
                                </div>
                            </div>
                        </div>
                    </header>
                    <div className="container">
                        <CommentAdd addComment={this.addComment}/>
                        <CommentList comments={comments} deleteComment={this.deleteComment}/>
                    </div>
                </div>

            </div>
        )
    }
}

app.jsx

import React, {Component} from 'react'
import PropTypes from 'prop-types';

export default class CommentAdd extends Component {
    //声明接受的属性
    static propTypes = {
        addComment: PropTypes.func.isRequired
    }

    state = {
        /*名字不能随便乱写，是根据app.jsx来写的*/
        username: '',
        content: ''
    }

    handleSubmit = () => {
        //收集数据(使用受控组件),并封装成comment对象
        const comment = this.state
        //更新状态
        this.props.addComment(comment)
        //清除输入数据
        this.setState({
            username: '',
            content: ''
        });
    }
    handleNameChange = (event) => {
        const username = event.target.value
        this.setState({username})
    }
    handleContentChange = (event) => {
        const content = event.target.value
        this.setState({content})
    };

    render() {
        const {username, content} = this.state
        return (
            <div className="col-md-4">
                <form className="form-horizontal">
                    <div className="form-group">
                        <label>用户名</label>
                        <input type="text" className="form-control" placeholder="用户名" value={username}
                               onChange={this.handleNameChange}/>
                    </div>
                    <div className="form-group">
                        <label>评论内容</label>
                        <textarea className="form-control" rows="6" placeholder="评论内容" value={content}
                                  onChange={this.handleContentChange}></textarea>
                    </div>
                    <div className="form-group">
                        <div className="col-sm-offset-2 col-sm-10">
                            <button type="button" className="btn btn-default pull-right"
                                    onClick={this.handleSubmit}>提交
                            </button>
                        </div>
                    </div>
                </form>
            </div>
        )
    }
};

comment-add.jsx

import React, {Component} from 'react';
import PropTypes from 'prop-types'
import './commentItem.css'

export default class CommentItem extends Component {
    static propTypes = {
        comment: PropTypes.object.isRequired,
        deleteComment: PropTypes.func.isRequired,
        index:PropTypes.number.isRequired
    }
    handleClick = () => {
        const {comment, deleteComment,index} = this.props
        //提示
        if (window.confirm(`确定删除${comment.username}的评论吗`)) {
            deleteComment(index);
        }
        //确定后删除
    }

    render() {
        const {comment} = this.props
        return (
            <li className="list-group-item">
                <div className="handle">
                    <a href="javascript:;" onClick={this.handleClick}>删除</a>
                </div>
                <p className="user"><span>{comment.username}</span><span>说:</span></p>
                <p className="centence">{comment.content}</p>
            </li>
        );
    }
}

comment-item.jsx

li {
    transition: .5s;
    overflow: hidden;
}

.handle {
    width: 40px;
    border: 1px solid #ccc;
    background: #fff;
    position: absolute;
    right: 10px;
    top: 1px;
    text-align: center;
}

.handle a {
    display: block;
    text-decoration: none;
}

.list-group-item .centence {
    padding: 0px 50px;
}

.user {
    font-size: 22px;
}

commentItem.css

import React, {Component} from 'react'
import PropTypes from 'prop-types'
import CommentItem from '../comment-item/comment-item'
import './commentList.css'

export default class CommentList extends Component {
    //指定组件类型.
    static propTypes = {
        comments: PropTypes.array.isRequired,
        deleteComment: PropTypes.func.isRequired
    };

    render() {
        const {comments, deleteComment} = this.props
        //判断是显示还是隐藏
        const display = comments.length === 0 ? 'block' : 'none'
        return (
            <div className="col-md-8">
                <h3 className="reply">评论回复：</h3>
                <h2 style={{display}}>暂无评论，点击左侧添加评论！！！</h2>
                <ul className="list-group">
                    {
                        comments.map((c, index) => <CommentItem comment={c} key={index} deleteComment={deleteComment}
                                                                index={index}/>)
                    }
                </ul>
            </div>
        )
    }
}
//这种属性方式有点麻烦
/*
CommentList.propTypes = {
    comments: PropTypes.array.isRequired
}*/