Javascript 使用提供程序时，React上下文不起作用

我正在简化尝试使用React更新

我希望当我单击标题Hello CodeSandbox时，加载栏会显示上下文api数据

代码示例：

使用上下文加载 消费者 加载组件应位于应用程序上下文提供程序内部

工作应用程序：

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谢谢你的回答。这令人失望。因为我希望在全局路由上加载，然后编辑来自任何组件的值。我想我真的得用Mobx了

export const LoadingState = {
  loading: false
};
const LoadingContext = React.createContext(LoadingState);

export const LoadingProvider = LoadingContext.Provider;
export const LoadingConsumer = LoadingContext.Consumer;

const LinearIndeterminate = function() {
  const { loading } = useContext(LoadingContext);
  return (
    <div>
      {loading && <LinearProgress color="secondary" />}
    </div>
  );
};

class App extends PureComponent {
  state = {
    loading: false
  };

  add = () => {
    const currentState = this.state.loading;
    this.setState({ loading: !currentState });
  };

  render() {
    console.info(this.state);
    return (
      <div className="App">
        <h1 onClick={this.add}>Hello CodeSandbox</h1>
        <Loading />
        <LoadingProvider value={this.state}>
          {this.state.loading}
        </LoadingProvider>
        <h2>Start editing to see some magic happen!</h2>
      </div>
    );
  }
}

 class App extends PureComponent {
  state = {
    loading: false
  };

  add = () => {
    const currentState = this.state.loading;
    this.setState({ loading: !currentState });
  };

  render() {
    console.info(this.state);
    return (
      <div className="App">
        <h1 onClick={this.add}>Hello CodeSandbox</h1>
        <LoadingProvider value={this.state}>
           <Loading /> /* This line is moved. */
        </LoadingProvider>
        <h2>Start editing to see some magic happen!</h2>
      </div>
    );
  }
}