如何从父导航器的标题图标调用子导航器屏幕中的函数

// 父导航器组件
import { createAppContainer } from 'react-navigation';
import { createStackNavigator } from 'react-navigation-stack';

// 子导航器屏幕组件
import ChildScreen from './ChildScreen';

// 父导航器配置
const ParentNavigator = createStackNavigator({
  Home: {
    screen: HomeScreen,
    navigationOptions: ({ navigation }) => ({
      headerTitle: '父导航器',
      headerTitleStyle: { alignSelf: 'center' },
      headerLeft: (
        <TouchableOpacity onPress={() => navigation.getParam('callChildFunction')()}>
          <Image source={require('icon.png')} style={{ width: 24, height: 24 }} />
        </TouchableOpacity>
      ),
    }),
  },
});

// 创建父导航器容器
const AppContainer = createAppContainer(ParentNavigator);

// 导出父导航器容器
export default AppContainer;

// 子导航器屏幕组件
import React from 'react';
import { View, Text } from 'react-native';

class ChildScreen extends React.Component {
  componentDidMount() {
    this.props.navigation.setParams({ callChildFunction: this.callChildFunction });
  }

  callChildFunction = () => {
    // 在这里执行子导航器屏幕中的函数
    console.log('子导航器屏幕中的函数被调用了！');
  };

  render() {
    return (
      <View>
        <Text>子导航器屏幕</Text>
      </View>
    );
  }
}

export default ChildScreen;