react native 父组件调用子组件方法(react通用)

父

class Home extends React.Component {

  componentDidMount(){
    //调用子组件方法
    this._child.testFun()
  }
  render(){
    return 
      <View>
        <Page ref={child => this._child = child}  />
      </View>
    }
}

子

class Page extends React.Component {

  testFun=()=>{
    alert(1)
  }
  render(){
    return 
      <View>
        <Text>我是子组件噢！<Text>
      </View>
  }
}