React 通过 props 传递函数的问题 - V2EX
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Oathbinder
V2EX    React

React 通过 props 传递函数的问题

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  •   Oathbinder 2018-02-02 15:27:56 +08:00 5830 次点击
    这是一个创建于 2809 天前的主题,其中的信息可能已经有所发展或是发生改变。
    class Parent extends Component { constructor(props) { super(props); this.state = { "id": "1" }; } setIdFromChildA = (id) => this.setState({ "id": id }); setIdFromChildB = (id) => this.setState({ "id": id }); render() { return ( <ChildA id={this.state.id} setId={this.setIdFromChildA} /> <ChildB id={this.state.id} setId={this.setIdFromChildB} /> ); } } class ChildA extends Component { constructor(props) { super(props); this.state = {...}; } componentDidMount() { this.foo() } foo() { this.props.setId("2"); } } class ChildB extends Component { constructor(props) { super(props); this.state = {...}; } handleClick = (e) => {this.props.setId("2")}; render() { return ( <button type="button" OnClick={this.handleClick} /> ); } 

    现在的问题是 ChildA 调用 setId 没有问题但是 ChildB 在调用时会报错TypeError: _this.props.setId is not a function。A 和 B 的区别在于一个是在componentDidMount()中执行另一个是 onClick 事件触发,是因为这个原因吗?

    7 条回复    2018-02-02 21:28:03 +08:00
    swirling
        1
    swirling  
       2018-02-02 16:00:02 +08:00 via iPhone
    我觉得应该是 a 报错 b 不报错才对吧
    50480350
        2
    50480350  
       2018-02-02 16:06:59 +08:00
    this.handleClick = this.handleClick.bind(this);
    brickyang
        3
    brickyang  
       2018-02-02 17:17:37 +08:00 via iPhone
    你在 childA 的 constructor() 里加上 this.foo = this.foo.bind(this) 试试
    brickyang
        4
    brickyang  
       2018-02-02 17:19:15 +08:00 via iPhone
    噢噢,眼花了,在 childB 的 constructor 里给 handleClick bind this 试试
    Oathbinder
        5
    Oathbinder  
    OP
       2018-02-02 17:47:56 +08:00
    @50480350 @brickyang
    绑定之后还是一样的错误,而且根据 React 的文档,如果使用箭头函数就不需要绑定了
    Mullvinn
        6
    Mullvinn  
       2018-02-02 17:54:58 +08:00
    跑了一下贴出来的代码,没发现报错,看看是不是其他哪里有问题
    yacolinqi
        7
    yacolinqi  
       2018-02-02 21:28:03 +08:00 via Android
    断点调试一下呗,或者在 handleClick 打印一下看看呗
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