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我试图用 typescript 设置 ContextApi 和 useReducer。在 useReducer 中的“issuesInitialState”变量上,出现错误:
没有重载匹配这个调用。
Overload 1 of 5, '(reducer: ({ state, action }: IssueReducer) => {}, initializerArg: never, initializer?: undefined): [never, DispatchWithoutAction]',给出了以下错误。
“IssuesInitialState”类型的参数不可分配给“never”类型的参数。
Overload 2 of 5, '(reducer: ({ state, action }: IssueReducer) => {}, initialState: never, initializer?: undefined): [never, Dispatch]',给出了以下错误。
“IssuesInitialState”类型的参数不可分配给“never”类型的参数。ts(2769)
// Store.tsx
type Issue = {
closeDate: string | null;
description: string;
issueId: number;
lastEditDate: string | null;
priorityId: string;
projectId: number;
reportDate: string;
statusId: string;
title: string;
userId: number;
};
interface IssuesInitialState {
issues: Issue[];
issue: Issue;
issuesByProject: Issue[];
updateIssue: Issue;
}
const issuesInitialState: IssuesInitialState = {
issues: [],
issue: {
closeDate: "",
description: "",
issueId: 0,
lastEditDate: "",
priorityId: "",
projectId: 0,
reportDate: "",
statusId: "",
title: "",
userId: 0,
},
issuesByProject: [],
updateIssue: {
closeDate: "",
description: "",
issueId: 0,
lastEditDate: "",
priorityId: "",
projectId: 0,
reportDate: "",
statusId: "",
title: "",
userId: 0,
},
};
export const IssuesContext = createContext<{
issuesState: IssuesInitialState;
issuesDispatch: any;
}>({ issuesState: issuesInitialState, issuesDispatch: () => null });
export function StoreProvider({ children }: any): JSX.Element {
const [commentsState, commentsDispatch] = useReducer(
commentsReducer,
commentsInitialState
);
const [issuesState, issuesDispatch] = useReducer(
issuesReducer,
issuesInitialState // where the error is!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
);
// IssuesReducer.ts
interface IssueReducer {
state: IssuesInitialState;
action: {
type: string;
payload: Issue;
};
}
export const issuesReducer = ({ state, action }: IssueReducer): {} => {
switch (action.type) {
case FETCH_ISSUES:
最佳答案
除了 Martin Lockett 指出的返回类型是一个空对象之外,您的 reducer 是一个带有单个参数的函数,它是一个具有属性 state 和 action 的对象,而实际上它应该是一个带有 2 个参数的函数,第一个是状态,第二个是 Action 。它可能会帮助您像这样输入 reducer :
import { Reducer } from 'react'
type IssuesAction = {
type: string;
payload: Issue;
}
export const issuesReducer: Reducer<IssuesInitialState, IssuesAction> = (state, action) => {
switch (action.type) {
...
关于reactjs - 使用 Typescript 设置 Context Api 和 useReducer 时出现 "No overload matches this call"错误,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/61694543/
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