javascript - 无法在 react 导航中使用 setParams 将函数设置为参数

Question

我正在尝试在单击已获得焦点的选项卡时在包含 ListView 的屏幕中设置滚动到顶部功能。

我正在使用 react-navigation 2.0.0 和 react-native 0.59.8这是我的导航器的样子:

FeedScreen.js returns
   render() {
    return <Nodes {...this.props} />;
  }

Nodes.js
   callScrollToTop = () => {
     this.listView.scrollToOffset({ offset: 0, animated: true });
   }
   componentDidMount(){
     this.props.navigation.setParams({
        scrollToTop: this.callScrollToTop
     })
   }
   // Here, I am able to set a string param like name: "Alice" and that can be seen in navigation state on TabBarOnPress 

const Feed = createStackNavigator({
  Feed: {
    screen: FeedScreen
  }
});

const Profile = createStackNavigator({
  Profile: {
    screen: ProfileScreen
  }
});

 const TabsScreens = createBottomTabNavigator(
  {
    Feed,
    Profile
  },
  {
    navigationOptions: ({ navigation }) => ({
    tabBarOnPress: ({ navigation }) => {
        if (
          navigation.isFocused() &&
          navigation.state.params &&
          navigation.state.params.scrollToTop
        ) {
          navigation.state.params.scrollToTop();
        }
   })
  })

我不想要像将 ListView 滚动到顶部这样的精确解决方案。能够在 componentDidMount 上将函数设置为参数并在 tabBarOnPress 上访问它就足够了。请帮我找到解决方案。

谢谢!!

Answer 1

在你各自的标签组件中使用这些，

import { NavigationEvents } from 'react-navigation';

render() {
   return (
    <View>
    <NavigationEvents
       onWillFocus={(route) => {
         if (route.action.routeName === /* check the screen name mentioned in the routes */) {
           //call the function u need
         }
       }}
     />
    // add other components as usual
    </View>
   );
}