夺命雷公狗-----React---28--小案例之react经典案例todos（全选和反选）完

这个功能实现的步骤如下所示：

最终实现全选和反选，代码如下所示：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <script src="./js/react.js"></script>
    <script src="./js/react-dom.js"></script>
    <script src="./js/browser.min.js"></script>
</head>
<body>
    <div id="dome"></div>
    <script type="text/babel">
        //搜索区域
        var Ck = React.createClass({
            //处理搜索事件的函数
            handleKey:function(e){
                //alert('test');
                //判断回车enter键才处理,keyCode13==回车键
                if(e.keyCode == 13){
                    //alert('test');
                    //如果搜索内容是空的让他不走了
                    if(!e.target.value) return;
                    //否则添加任务了
                    var ckcon = {
                        text : e.target.value,
                        isDown: false
                    }
                    //利用属性完成
                    this.props.addCkcon(ckcon);
                    //清空搜索框的内容
                    e.target.value = '';
                }

            },
            render:function(){
                return(
                    <div>
                        <input type="text" placeholder="你要干嘛？" onKeyUp={this.handleKey} />
                    </div>
                );
            }
        });
        //列表项区域
        var Lists = React.createClass({
            handleClick:function(){
                //alert('test');
                this.props.deleteCkcon(this.props.index);
            },
            //处理单选框的变化事件
            handleChange:function(e){
                //修改那个任务，修改的值是什么
                this.props.changeStatus(this.props.index,e.target.checked);
            },
            render:function(){
                return(
                    <li>
                        <label>
                            <input type="checkbox" checked={this.props.todo.isDown} onChange={this.handleChange} />
                            {this.props.todo.text}
                        </label>
                        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                        <button onClick={this.handleClick}>删除</button>
                    </li>
                );
            }
        });
        //列表框区域
        var Ul = React.createClass({
            render:function(){
                //保存this指针
                var _this = this;
                return(
                    <ul>
                        {
                            this.props.todos.map(function(item,index){
                                return <Lists todo={item} key={index} index={index} deleteCkcon={_this.props.deleteCkcon} changeStatus={_this.props.changeStatus} />
                            })
                        }
                    </ul>
                );
            }
        });
        //状态组建
        var Status = React.createClass({
            handleClick:function(){
                //alert('test');
                //删除已完成的
                this.props.deleteDown();
            },
            handleChange:function(e){
                this.props.changeAllStatus(e.target.checked);
            },
            render:function(){
                return(
                    <div>
                        <input type="checkbox" checked={this.props.isAllChecked} onChange={this.handleChange} />
                        {this.props.countDown} 已完成  /  {this.props.total} 总数
                        &nbsp;&nbsp;&nbsp;
                        <button onClick={this.handleClick}>清除已完成</button>
                    </div>
                );
            }
        });
        //总组建
        var Zong = React.createClass({
            getInitialState:function(){
                return {
                    todos :[
                        {text:'6点起床',isDown:true},
                        {text:'7点出门',isDown:true},
                        {text:'8点吃早饭',isDown:false},
                        {text:'9点上班',isDown:true},
                        {text:'12点下班',isDown:false}
                    ],
                    isAllChecked: false
                }
            },
            addCkcon:function(todo){
                //接收到用户的添加的内容然后铺push过去即可
                this.state.todos.push(todo);
                //然后更新state
                this.setState({
                    todos : this.state.todos
                });
            },
            //处理删除任务
            deleteCkcon:function(index){
                //用函数splice来删除掉指定的数组元素
                this.state.todos.splice(index,1);
                //删除完成后来更新下页面的内容
                this.setState({
                    todos : this.state.todos
                });
            },
            //任务单选框的属性
            changeStatus:function(index,isDown){
                this.state.todos[index].isDown = isDown
                this.setState({
                    todos : this.state.todos
                })
                this.checkAll();
            },
            //如果所有任务都完成了，就设置isAllChecked都为true
            checkAll:function(){
                if(this.state.todos.every(function(todo){ return todo.isDown})){
                    this.setState({
                        isAllChecked:true
                    });
                }else{
                    this.setState({
                        isAllChecked:false
                    });
                }
            },
            //统计总的任务个数
            total:function(){
                return this.state.todos.length || 0
            },
            //统计已完成的
            countDown:function(){
                var arr = this.state.todos.filter(function(todo){
                    return todo.isDown
                });
                return arr.length || 0;
            },
            //删除已完成的任务
            deleteDown:function(){
                var arr = this.state.todos.filter(function(todo){
                    return !todo.isDown
                });
                this.setState({
                    todos:arr
                });
                this.checkAll();
            },
            changeAllStatus:function(isDown){
                //修改todos里面每个任务的状态
                this.state.todos.forEach(function(todo){
                    todo.isDown = isDown;
                });
                //修改isAllChecked里面的值
                this.setState({
                    todos:this.state.todos,
                    isAllChecked:isDown
                });

            },
            render:function(){
                return(
                    <div>
                        <Ck addCkcon={this.addCkcon} />
                        <Ul todos={this.state.todos} deleteCkcon={this.deleteCkcon} changeStatus={this.changeStatus} />
                        <Status total={this.total()} countDown={this.countDown()} deleteDown={this.deleteDown} isAllChecked={this.state.isAllChecked} changeAllStatus={this.changeAllStatus} />
                    </div>
                );
            }
        });
        ReactDOM.render(
            <Zong />,
            document.getElementById('dome')
        );
    </script>
</body>
</html>