如何在createBottomTabNavigator中使用AsyncStorage和React Navigation？

Question

我使用react-navigation v3，我想在createBottomTabNavigator中使用AsyncStorage来检查用户是否已记录。

我在登录屏幕中将密钥保存到存储：

await AsyncStorage.setItem('@MyStorage:isLogged', isLogged);

我想在我的堆栈中使用AsyncStorage（TabStack）：

const TabStack = createBottomTabNavigator(
  {
    Home: { screen: HomeScreen, },
    // I need isLogged key from AsyncStorage here!
    ...(false ? {
      Account: { screen: AccountScreen, }
    } : {
      Login: { screen: LoginScreen, }
    }),
  },
  {
    initialRouteName: 'Home',
  }
);

我怎么能这样做？

我的环境：

• 反应原生：0.58.5
• 反应导航：3.3.2

Answer 1

您不需要这样做，只是想在登录屏幕中检查有效的会话。

您需要创建2个堆栈，一个用于auth屏幕，而您的TabStack用于logged用户：

const TabStack = createBottomTabNavigator({
    Home: { screen: HomeScreen, },
    Account: { screen: AccountScreen, }
},
{
  initialRouteName: 'Home',
  headerMode: 'none',
  navigationOptions: {
    headerVisible: false,
  }
});

const stack = createStackNavigator({
  Home: {screen: TabStack},
  Login: { screen: LoginScreen, }
});

然后在方法LoginScreen中检查componentDidMount中的有效会话。

class LoginScreen extends Component {
  componentDidMount(){
    const session = await AsyncStorage.getItem('session');

    if (session.isValid) {
      this.props.navigate('home')
    }
  }
}

Answer 2

解决方案是：创建一个新组件AppTabBar并在tabBarComponent属性中设置它

const TabStack = createBottomTabNavigator({
    Home: { screen: HomeScreen, },
    Account: { screen: AccountScreen, }
},
{
  initialRouteName: 'Home',
  tabBarComponent: AppTabBar, // Here
});

和AppTabBar组件：

export default class AppTabBar extends Component {
  constructor(props) {
    super(props);

    this.state = {
      isLogged: '0',
    };
  }

  componentDidMount() {
    this._retrieveData();
  }

  _retrieveData = async () => {
    try {
      const value = await AsyncStorage.getItem('isLogged');
      if (value !== null) {
        this.setState({
          isLogged: value,
        });
      }
    } catch (error) {
      // Error retrieving data
    }
  };

  render() {
    const { navigation, appState } = this.props;
    const routes = navigation.state.routes;
    const { isLogged } = this.state;

    return (
      <View style={styles.container}>
        {routes.map((route, index) => {
          if (isLogged === '1' && route.routeName === 'Login') {
            return null;
          }

          if (isLogged === '0' && route.routeName === 'Account') {
            return null;
          }

          return (
            <View /> // here your tabbar component
          );
        })}
      </View>
    );
  }

  navigationHandler = name => {
    const { navigation } = this.props;
    navigation.navigate(name);
  };
}

Answer 3

在“加载”屏幕中，从AsyncStorage读取登录状态，并将其存储在Redux存储中（或您选择的任何类型的全局数据共享机制） - 我在这里使用redux，然后在堆栈中读取这段数据组件如下：

import React from "react";
import { View, Text } from "react-native";
import { connect } from "react-redux";
import { createStackNavigator } from "react-navigation";

class Stack extends React.Component {
  render() {
    const { isLoggedIn } = this.props.auth;

    const RouteConfigs = {
      Home: () => (
        <View>
          <Text>Home</Text>
        </View>
      ),
      Login: () => (
        <View>
          <Text>Login</Text>
        </View>
      )
    };

    const RouteConfigs_LoggedIn = {
      Home: () => (
        <View>
          <Text>Home</Text>
        </View>
      ),
      Account: () => (
        <View>
          <Text>Account</Text>
        </View>
      )
    };

    const NavigatorConfig = { initialRouteName: "Login" };

    const MyStack = createStackNavigator(
      isLoggedIn ? RouteConfigs_LoggedIn : RouteConfigs,
      NavigatorConfig
    );

    return <MyStack />;
  }
}

const mapStateToProps = ({ auth }) => ({ auth });

export default connect(mapStateToProps)(Stack);