React js从父组件更改子组件的状态

JavaScript

ItachiGreen

2020-03-13

我有两个组件: 父组件,我想从中更改子组件的状态:

class ParentComponent extends Component {
  toggleChildMenu() {
    ?????????
  }
  render() {
    return (
      <div>
        <button onClick={toggleChildMenu.bind(this)}>
          Toggle Menu from Parent
        </button>
        <ChildComponent />
      </div>
    );
  }
}

子组件

class ChildComponent extends Component {
  constructor(props) {
    super(props);
    this.state = {
      open: false;
    }
  }

  toggleMenu() {
    this.setState({
      open: !this.state.open
    });
  }

  render() {
    return (
      <Drawer open={this.state.open}/>
    );
  }
}

我需要从父组件更改子组件的打开状态,还是单击父组件中的按钮时从父组件调用子组件的toggleMenu()

第1387篇《React js从父组件更改子组件的状态》来自Winter(https://github.com/aiyld/aiyld.github.io)的站点

4个回答
飞羽 2020.03.13

您可以从父级发送道具并在子组件中使用它,以便将子状态的更改基于已发送的道具更改,并且可以通过在子组件中使用getDerivedStateFromProps来处理

Sam神奇 2020.03.13

父组件可以管理将道具传递给孩子的子状态,并且子组件使用componentWillReceiveProps将其转换为状态。

class ParentComponent extends Component {
  state = { drawerOpen: false }
  toggleChildMenu = () => {
    this.setState({ drawerOpen: !this.state.drawerOpen })
  }
  render() {
    return (
      <div>
        <button onClick={this.toggleChildMenu}>Toggle Menu from Parent</button>
        <ChildComponent drawerOpen={this.state.drawerOpen} />
      </div>
    )
  }
}

class ChildComponent extends Component {
  constructor(props) {
    super(props)
    this.state = {
      open: false
    }
  }

  componentWillReceiveProps(props) {
    this.setState({ open: props.drawerOpen })
  }

  toggleMenu() {
    this.setState({
      open: !this.state.open
    })
  }

  render() {
    return <Drawer open={this.state.open} />
  }
}
西里米亚 2020.03.13

上面的答案对我来说部分正确,但是在我的场景中,我想将值设置为状态,因为我已使用该值显示/切换模态。所以我已经使用了如下。希望它会帮助某人。

class Child extends React.Component {
  state = {
    visible:false
  };

  handleCancel = (e) => {
      e.preventDefault();
      this.setState({ visible: false });
  };

  componentDidMount() {
    this.props.onRef(this)
  }

  componentWillUnmount() {
    this.props.onRef(undefined)
  }

  method() {
    this.setState({ visible: true });
  }

  render() {
    return (<Modal title="My title?" visible={this.state.visible} onCancel={this.handleCancel}>
      {"Content"}
    </Modal>)
  }
}

class Parent extends React.Component {
  onClick = () => {
    this.child.method() // do stuff
  }
  render() {
    return (
      <div>
        <Child onRef={ref => (this.child = ref)} />
        <button onClick={this.onClick}>Child.method()</button>
      </div>
    );
  }
}

参考-https: //github.com/kriasoft/react-starter-kit/issues/909#issuecomment-252969542

达蒙Eva 2020.03.13

状态应在父组件中进行管理。您可以open通过添加属性传输到子组件。

class ParentComponent extends Component {
   constructor(props) {
      super(props);
      this.state = {
        open: false
      };

      this.toggleChildMenu = this.toggleChildMenu.bind(this);
   }

   toggleChildMenu() {
      this.setState(state => ({
        open: !state.open
      }));
   }

   render() {
      return (
         <div>
           <button onClick={this.toggleChildMenu}>
              Toggle Menu from Parent
           </button>
           <ChildComponent open={this.state.open} />
         </div>
       );
    }
}

class ChildComponent extends Component {
    render() {
      return (
         <Drawer open={this.props.open}/>
      );
    }
}

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