Question

仅当我在主页（屏幕）上并单击“后退”按钮时，我才需要退出react-native应用程序，虽然我已经编写了代码，但它从每个屏幕退出了该应用程序。我正在使用Router-Flux进行路由，请有人帮助我解决问题，到目前为止，我已经尝试过：

componentDidMount = async () => {
BackHandler.addEventListener("hardwareBackPress", this.handleBackPress);
}
componentWillUnmount() {       
BackHandler.removeEventListener("hardwareBackPress", 
this.handleBackPress);
}

handleBackPress = () => {

Alert.alert(
'Exit App',
'Do you want to exit?',
[
{text: 'No', onPress: () => console.log('Cancel Pressed'), style: 
'cancel'},
{text: 'Yes', onPress: () => BackHandler.exitApp()},
],
{ cancelable: false });
return true;
};

Code in my component Homepage.js

import { BackHandler, Alert} from 'react-native';
componentDidMount = async () => {
BackHandler.addEventListener("hardwareBackPress", this.handleBackPress);
}

componentWillUnmount() {      
BackHandler.removeEventListener("hardwareBackPress", 
this.handleBackPress);
}

handleBackPress = () => {

Alert.alert(
'Exit App',
'Do you want to exit?',

 [
{text: 'No', onPress: () => console.log('Cancel Pressed'), style: 
'cancel'},
{text: 'Yes', onPress: () => BackHandler.exitApp()},
],
{ cancelable: false });
return true;
};

Code in my Routes.js

import { Router, Stack, Scene } from 'react-native-router-flux';
<Router>
<Stack key="root" hideNavBar={true}>
<Scene key="login" component={Login} title="Login" initial={true} />
<Scene key="homepage" component={Homepage} title="Home"  />
<Scene key="history" component={HistoryAll} title="HistoryAll" />
</Stack>
</Router>

I was expecting that when I am on Homepage.Js and click on back button it 
will exit the app, its happening but it exits the App from every screen 
of the app.

Answer 1

您可以使用Actions.state.index作为支票。如果等于1，则退出应用程序，否则，您可以根据需要pop()或使用任何其他功能。

onBackPress() {

        if (Actions.state.index === 1) {

            BackHandler.exitApp();
            return false;
        }

        Actions.pop();
        return true;

    }

希望有帮助！

单击“后退”按钮时需要退出react-native应用程序，但仅从主页即可

1 个答案: