我正在寻找一种使用react-navigation在我的react-native应用程序中管理全局状态的方法。我尝试实现基本的React Context,我想将它包装在react-navigation的\0
方法周围,但是它没有用。
我最终使用Context的HOC从createAppContainer()
文件包装了一个应用程序容器,但是当Context的状态更改时,似乎反应导航在嵌套组件的重新渲染方面存在问题。我可以从嵌套的组件访问我的上下文,但是当上下文状态更改时,它们不会被重新渲染。
我的index.js
文件如下:
index.js
我的上下文类如下:
import { AppRegistry } from "react-native";
import App from "./src/App";
import { withAppContextProvider } from "./src/AppContext";
import { name as appName } from "./app.json";
AppRegistry.registerComponent(appName, () => withAppContextProvider(App));
我的// for new react static context API
export const AppContext = createContext({});
// create the consumer as higher order component
export const withAppContext = ChildComponent => props => (
<AppContext.Consumer>
{context => <ChildComponent {...props} global={context} />}
</AppContext.Consumer>
);
// create the Provider as higher order component (only for root Component of the application)
export const withAppContextProvider = ChildComponent => props => (
<AppContextProvider>
<ChildComponent {...props} />
</AppContextProvider>
);
export class AppContextProvider extends Component {
state = {
isOnline: true
};
handleConnectivityChange = isOnline => {
this.setState({ isOnline });
};
componentDidMount = async () => {
NetInfo.isConnected.addEventListener(
"connectionChange",
this.handleConnectivityChange
);
};
componentWillUnmount() {
NetInfo.isConnected.removeEventListener(
"connectionChange",
this.handleConnectivityChange
);
}
render() {
return (
<AppContext.Provider
value={{
...this.state
}}
>
{this.props.children}
</AppContext.Provider>
);
}
}
文件看起来像:
App.js
const HomeStack = createStackNavigator(
{
Home: HomeScreen,
Cities: CitiesScreen
},
getStackConfig({ initialRouteName: "Home" })
);
const SettingsStack = createStackNavigator(
{
Settings: SettingsScreen
},
getStackConfig({ initialRouteName: "Settings" })
);
export default createAppContainer(
createBottomTabNavigator(
{
Home: HomeStack,
Settings: SettingsStack
}
)
);
组件示例:
CitiesScreen
现在,当我从import { AppContext } from "../AppContext";
class CitiesScreen extends Component {
static contextType = AppContext;
render() {
return (
<View style={styles.container}>
<Text>This value should change on isOnline update: {this.context.isOnline}</Text>
</View>
);
}
}
组件访问Context时,我目前能够获取CitiesScreen
上下文状态的值,但是每当我切换互联网连接时(在android上模拟器)打开/关闭,上下文状态已更改,但未重新呈现组件,并且未触发我的isOnline
方法。有什么帮助吗?
答案 0 :(得分:0)
就我而言,我将React从16.8降级为16.5.0,React导航版本为3。 我仍在调查,但这只是暂时的解决方案。