React ref不能写在render之外的地方，那有这种需求的时候怎么办？

Question

例如点击按钮就新增一个子组件，同时需要使用ref引用子组件，我像下面这样把ref写在handleClick里面时，因为不在render里面，会报错:addComponentAsRefTo(...): Only a ReactOwner can have refs.

var Father = React.createClass({
    getInitalState:function(){
        return {children:[]}
    },
    handleClick:function(){
       var childrenTemp = this.state.children
       this.setState{children:childrenTemp.push(<Child ref="childRef">)}
    },
    
    render:function(){
        return (
            <div>{this.state.children}</div>
        )
    }
})

Answer 1

组件不要直接保存在state里就可以啦

var Father = React.createClass({
    getInitalState:function(){
        return {
            children:[]
        }
    },

    handleClick:function(){
        var childrenTemp = this.state.children;

        this.setState({
            children : childrenTemp.push({id : 'id'})
        })
    },

    render:function(){
        var childrenTemp = this.state.children;

        return (
            <div>
                {
                    childrenTemp.map(function(item, index){
                        return <Child key={index} ref={item.id}>
                    })
                }
            </div>
        )
    }
});