（参数）状态：未知对象的类型为“未知”。还原TS

Question

const submitted = useSelector((state) => state.post.submitted)

对于上述 at 状态。我收到错误：

（参数）状态：未知对象的类型为“未知”。

这是如何固定的？

我有简单的切片+存储：

const submitted = useSelector((state) => state.post.submitted)

import { createSlice } from '@reduxjs/toolkit'

export const postSlice = createSlice({
  name: 'post',
  initialState: {
    shared: false,
    submitted: false,
  },
  reducers: {
    setShared: (state, action) => {
      state.shared = action.payload
    },
    setSubmitted: (state, action) => {
      state.submitted = action.payload
    },
  },
})

export const { setShared, setSubmitted } = postSlice.actions
export default postSlice.reducer

我在 Javascript 上没有遇到这种类型的错误，但在 TS 中会弹出？如果需要的话，需要声明什么类型的类型？

Answer 1

您应该遵循TypeScript 快速入门指南并设置正确类型的挂钩：

// store.ts

// Infer the `RootState` and `AppDispatch` types from the store itself
export type RootState = ReturnType<typeof store.getState>
// Inferred type: {posts: PostsState, comments: CommentsState, users: UsersState}
export type AppDispatch = typeof store.dispatch

//hooks.ts

import { TypedUseSelectorHook, useDispatch, useSelector } from 'react-redux'
import type { RootState, AppDispatch } from './store'

// Use throughout your app instead of plain `useDispatch` and `useSelector`
export const useAppDispatch = () => useDispatch<AppDispatch>()
export const useAppSelector: TypedUseSelectorHook<RootState> = useSelector

Answer 2

useSelector是泛型，无法确定state是什么类型，因此默认为unknown. 您需要为 state 提供一个与 的形状相匹配的类型注释initialState，因此您需要将其从切片定义中删除。

1. 定义接口（如果您愿意，也可以使用类型/类型别名）

interface MyState {
  shared: boolean
  submitted: boolean
}

2. 类型转换initialState，或使用中间类型变量（我认为这是可选的，但查看文档示例表明这是可能的）：

  // ...
  initialState: {
    shared: false,
    submitted: false,
  } as MyState,
  // ...

3. 向回调添加类型注释

const submitted = useSelector((state: MyState) => state.post.submitted)