Javascript 使用上下文提供程序包装React本机应用程序
我一直在遵循一些()来了解如何在我的React原生应用程序中使用React的上下文并处理身份验证 此示例使用有状态组件进行查看,并在组件本身内处理应用程序路由,例如: 和我的Javascript 使用上下文提供程序包装React本机应用程序,javascript,reactjs,react-native,react-context,Javascript,Reactjs,React Native,React Context,我一直在遵循一些()来了解如何在我的React原生应用程序中使用React的上下文并处理身份验证 此示例使用有状态组件进行查看,并在组件本身内处理应用程序路由,例如: 和我的AppNavigator.js: /* AppNavigator.js */ import React from 'react'; import { createAppContainer, createSwitchNavigator } from 'react-navigation'; import AuthLoadin
AppNavigator.js
:
/* AppNavigator.js */
import React from 'react';
import { createAppContainer, createSwitchNavigator } from 'react-navigation';
import AuthLoadingScreen from '../screens/AuthLoadingScreen';
import Auth from './AuthNavigator';
import App from './AppTabNavigator';
export default createAppContainer(createSwitchNavigator(
{
AuthLoading: AuthLoadingScreen,
Auth,
App,
},
{
initialRouteName: 'AuthLoading',
}
));
(AuthNavigator
和AppTabNavigator
仅包含createStackNavigator()
,其中定义了我的屏幕。)
我的问题是:我如何用我的上下文包装这个应用程序,以便上下文提供商始终知道导航道具,这样我就可以处理从上下文提供商本身登录、注销和路由用户的问题?我通过使用非常有用的内置模块来解决这个问题。我通过使用,为此目的设计的非常有用的内置模块
/* SignInScreen.js - MODIFIED */
import React from 'react';
import { Button, View } from 'react-native';
import { MyContext } from '../Provider';
export default const LoginScreen = () => {
return (
<View>
<MyContext.Consumer>
{context => {
return (
<Button
onPress={() => context.signIn()}
title="Sign In"
/>
)
}
}
</MyContext.Consumer>
</View>
)
};
/* Provider.js */
import React from 'react';
import { AsyncStorage } from 'react-native';
export const MyContext = React.createContext();
export default class MyProvider extends React.Component {
constructor(props) {
super(props);
this.getToken = () => AsyncStorage.getItem('userToken');
this.saveToken = () => AsyncStorage.setItem('userToken', 'abc');
this.removeToken = () => AsyncStorage.removeItem('userToken');
this.signIn = () => {
this.saveToken()
.then((data) => {
// this.props.navigation DOES NOT EXIST!!! :(
this.props.navigation.navigate('App');
})
.catch((error) => this.setState({ error }));
};
this.state = {
token: '',
signIn: this.signIn,
};
}
componentWillMount() {
AsyncStorage.getItem('userToken')
.then((token) => {
this.setState({ token })
})
.catch(error => {
this.setState({ error })
})
}
render() {
return (
<MyContext.Provider value={this.state}>
{this.props.children}
</MyContext.Provider>
);
}
}
/* App.js */
import React from 'react';
import { View } from 'react-native';
import MyContext from './Provider';
import AppNavigator from './navigation/AppNavigator';
export default class App extends React.Component {
render() {
return (
<MyContext>
<View>
<AppNavigator />
</View>
</MyContext>
);
}
}
/* AppNavigator.js */
import React from 'react';
import { createAppContainer, createSwitchNavigator } from 'react-navigation';
import AuthLoadingScreen from '../screens/AuthLoadingScreen';
import Auth from './AuthNavigator';
import App from './AppTabNavigator';
export default createAppContainer(createSwitchNavigator(
{
AuthLoading: AuthLoadingScreen,
Auth,
App,
},
{
initialRouteName: 'AuthLoading',
}
));