React Native Context 在包裹在內部時呈現空白屏幕<provider></provider>

Question

我正在嘗試使用上下文構建一個簡單的博客本機應用程序，但偶然發現了一個我找不到根源的問題。

這是它的結構：

/context/createDataContext.js 文件：

import React, { useReducer } from "react"; 
export default (reducer, actions, initialState) => {
const Context = React.createContext();
const Provider = ({ childern }) => {
const [state, dispatch] = useReducer(reducer, initialState);
const boundActions = {};
for (let key in boundActions) {
  boundActions[key] = actions[key](dispatch);
}
return (
  <Context.Provider value={{ state, ...boundActions }}>
    {childern}
  </Context.Provider>
);
};
return { Context, Provider };
};

/上下文/BlogContext.js：

import createDataContext from "./createDataContext";

const blogReducer = (state, action) => {
switch (action.type) {
case "add_blogpost":
  return [...state, { title: `Blog Post Number ${state.length + 1}` }];
default:
  return state;
}
};
const addBlogPost = (dispatch) => {
return () => {
dispatch({ type: "add_blogpost" });
};
};
export const { Context, Provider } = createDataContext(
blogReducer,
{ addBlogPost },
[]
);

/屏幕/IndexScreen.js：

 import React, { useContext } from "react"; import { View, Text, StyleSheet, FlatList, Button } from "react-native"; import { Context } from "../context/BolgContext"; const IndexScreen = () => { const { state, addBlogPost } = useContext(Context); return ( <View> <Button title="Add a blod post" onPress={addBlogPost} /> <FlatList data={state} keyExtractor={(blogPost) => blogPost.title} renderItem={({ item }) => { return <Text>{item.title}</Text>; }} /> </View> ); }; const styles = StyleSheet.create({}); export default IndexScreen;

最后是 App.js：

 import { NavigationContainer } from "@react-navigation/native"; import { createStackNavigator } from "@react-navigation/stack"; import IndexScreen from "./src/screens/IndexScreen"; import { Provider } from "./src/context/BolgContext"; import React from "react"; const Stack = createStackNavigator(); export default function App() { return ( <NavigationContainer> { <Provider> <Stack.Navigator initialRouteName="Home"> <Stack.Screen name="Home" component={IndexScreen} options={{ title: "My app" }} /> </Stack.Navigator> </Provider> } </NavigationContainer> ); }

現在我做了一些調試，即使代碼沒有返回任何錯誤，但問題似乎出在我的提供程序上，因為如果我刪除它，我可以在屏幕上看到內容。 有誰知道為什么會這樣。

非常感謝！

Answer 1

您需要像下面這樣更改 Provider 方法

形式

const Provider = ({ childern }) => {

到

const Provider = (props) => {

然后你可以在傳遞給 content.provider 的同時進行解構，如下所示

    <Context.Provider value={{ state, ...boundActions }}>
    {props.childern}
  </Context.Provider>