React Native 监听物理返回键的完美解决

//导入
import { createStackNavigator } from '@react-navigation/stack';
import {
  ...
    BackHandler,
} from 'react-native';
const Stack = createStackNavigator();

function App(props) {
    let lastBackPressed = Date.now();
    const onBackAndroid = () => {
        if (lastBackPressed && lastBackPressed + 2000 >= Date.now()) {
            BackHandler.exitApp();
            return false;
        }
        lastBackPressed = Date.now();
        Toast('再按一次退出应用');
        return true;
    }

      return (
        <Stack.Navigator initialRouteName="main" screenOptions={props => {
            /********************核心代码***********************/
            // 使用的时候只需要把'HomePage'换成你工程里的首页就可以了。
            const { navigation, route } = props;
            if (route.name === 'HomePage' && navigation.isFocused()) {
                BackHandler.addEventListener('hardwareBackPress', onBackAndroid);
            } else if (route.name !== 'HomePage' && navigation.isFocused()) {
                console.log("==-=-=-=other");
                BackHandler.removeEventListener('hardwareBackPress', () => { return true; });
            }
            /********************核心代码***********************/    
            return {
                headerBackImage: () => (...),
                ...
                headerStyle: {
                    elevation: 0,
                },
                ...
            };
        }}>
            <Stack.Screen
                name="HomePage"
                component={HomePage}
            />
            ....
        </Stack.Navigator>
}