javascript - React native - 防止用户返回登录屏幕

Question

我使用 Facebook SDK 创建了一个登录按钮。用户登录后，应用程序将导航到第二个屏幕 (NavigatorIOS)。从第二个屏幕，用户可以使用导航(后退按钮)返回登录屏幕。

如果用户已经登录，我如何防止他返回登录屏幕？

index.ios.js

import React, { Component } from 'react'

import {
  AppRegistry,
  StyleSheet,
  NavigatorIOS
} from 'react-native'

import LoginView from './src/login-view'

class MyApp extends Component {
  render() {
    return (
      <Provider store={store}>
        <NavigatorIOS
          initialRoute={{
            component: LoginView,
            title: 'MyApp',
            index: 0
          }}
        />
      </Provider>
    );
  }
}
AppRegistry.registerComponent('MyApp', () => MyApp);

登录 View

import React, {Component} from 'react'
import {
    View,
    Text,
    StyleSheet,
    TouchableHighlight,
} from 'react-native'

import CategoryView from './category-view'

import {LoginButton, AccessToken, GraphRequest, GraphRequestManager} from 'react-native-fbsdk'

class LoginView extends Component {
    goToCategoryView = () =>
        this.props.navigator.push({
            title: 'Categories',
            component: CategoryView,
        })

    render(){
        return(
            <View style={styles.container}>
                <LoginButton
                    readPermissions={['public_profile','email']}
                    onLoginFinished={
                        (error, result) => {
                            if (error) {
                                console.log('login has error: ', result.error)
                            } else if (result.isCancelled) {
                                console.log('login is cancelled.')
                            } else {
                                AccessToken.getCurrentAccessToken().then((data) => {    
                                    this.goToCategoryView()
                                })
                            }
                        }
                    }
                    onLogoutFinished={() => {console.log('logged out')}} />
            </View>
        )
    }
}

export default LoginView

Answer 1

使用 Navigator，您可以使用 resetTo(startingRoute) 方法来重置堆栈，并从您过去的路线作为参数开始一个新的堆栈。这样做会阻止在堆栈中返回导航。

如果我没有误解你的组件，你应该使用这样的东西:

goToCategoryView = () => {
    //Replace here push with resetTo
    this.props.navigator.resetTo({
        title: 'Categories',
        component: CategoryView,
    })
}

Facebook Docs