ReactJs如何从父级访问子组件引用

Question

如何访问父项中的子项的引用以在父函数中对它们执行某些操作？

class Parent extends Component {

  someFunction(){
  // how to access h1 element of child in here ??
  }

  render() {
    return (
      <Child />
    );
  }
}



class Child extends Component {
  render() {
    return (
      <h1 ref="hello">Hello</h1>
    );
  }
}

Answer 1

要添加Shubham的答案,必须在父级内的componentDidMount()内访问子引用.就像是:

class Parent extends React.Component {
    componentDidMount(){
        var elem1 = this.refs.child1.refs.childRefName;
    }

    return (
    <View>
      <Child1 ref='child1'/>
      <Child2 />
      <Child3 />
    </View>
    );
}