React hook UseContext没有返回正确的值（根据typescript）

Question

我有以下代码接收dispatch方法：

const mapDispatchToProps = (dispatch: React.Dispatch<AppAction>) => ({

});

我像这样使用useContext ;

    const appContext = useContext(AppContext);
    const [state, dispatch] = appContext;

运行mapDispatchToProps(dispatch); 但是我收到以下错误：

Error:(28, 24) TS2345: Argument of type '[AppState, Dispatch<AppAction>]' is not assignable to parameter of type 'Dispatch<AppAction>'. Type '[AppState, Dispatch<AppAction>]' provides no match for the signature '(value: AppAction): void'.

它认为dispatch仍然是阵列......发生了什么？

Answer 1

事实证明，您必须为您的上下文声明类型，如下所示：

export const AppContext = React.createContext<[AppState, Dispatch<AppAction>] | null>(null);

而不是export const AppContext = React.createContext<Array<[AppState, Dispatch<AppAction>]> | null>(null); export const AppContext = React.createContext<Array<[AppState, Dispatch<AppAction>]> | null>(null);