管理员处于休息状态，包括在另一个反应应用程序中"MuiThemeProvider.render()"错误

Question

>我尝试按照有关它的文档在另一个应用程序中使用 admin on rest，但是当我尝试使用 AppBar 时出现错误

MuiThemeProvider.render(): A valid React element (or null) must be returned. You may have returned undefined, an array or some other invalid object.
const App = () => (
<Provider store={store}>
<TranslationProvider /*messages={messages}*/>
<ConnectedRouter history={history}>
<MuiThemeProvider >
<AppBar title="My Admin" />
<Switch>
<Route exact path="/" component={Dashboard} render={(routeProps) => <EventList resource="event" {...routeProps} />}/>
<Route exact path="/event" hasCreate render={(routeProps) => <EventList resource="event" {...routeProps} />} />
<Route exact path="/event/create" render={(routeProps) => <EventCreate resource="event" {...routeProps} />} />
<Route exact path="/event/:id" hasDelete render={(routeProps) => <EventEdit resource="event" {...routeProps} />} />
</Switch>
</MuiThemeProvider>
</ConnectedRouter>
</TranslationProvider>
</Provider>);
export default App;

有人知道吗？ 谢谢

Answer 1

><MuiThemeProvider>需要有一个孩子，所以你里面的任何东西都需要被包裹起来。

例如

<MuiThemeProvider>
<div>
<AppBar title="My Admin" />
<Switch>
<Route exact path="/" component={Dashboard} render={(routeProps) => <EventList resource="event" {...routeProps} />}/>
<Route exact path="/event" hasCreate render={(routeProps) => <EventList resource="event" {...routeProps} />} />
<Route exact path="/event/create" render={(routeProps) => <EventCreate resource="event" {...routeProps} />} />
<Route exact path="/event/:id" hasDelete render={(routeProps) => <EventEdit resource="event" {...routeProps} />} />
</Switch>
</div>
</MuiThemeProvider>