reactjs - 打字稿和钩子
问题描述
谁能告诉我使用 Typescript 将此钩子转换为类型安全版本的最佳方法。它是一个简单的切换,可以在切换状态下显示不同的“事物”。
使用切换.js
const useToggleButton = ({on,off}) => {
const [toggle, setToggle] = React.useState(false)
const ToggleButton = () => (
<div
role="button"
onClick={() => setToggle(!toggle)}
data-testid="portal-toggle-btn"
>
{toggle? on : off}
</div>
)
return [ToggleButton, toggle, setToggle]
}
问题是它返回一个包含组件、状态和 setState 函数的数组。我的尝试在下面,但我得到了错误
TS2605: JSX element type 'IReturnType' is not a constructor function for JSX elements. Type 'IReturnType' is missing the
following properties from type 'Element': type, props, key
TS2739: Type '(boolean | Dispatch<SetStateAction<boolean>>)[]' is
missing the following properties from type 'IReturnType': component,
state, func
使用切换.tsx
import * as React from 'react'
interface IToggleBntProps {
on: any
off: any
}
interface IState {
bol: boolean
}
interface IReturnType {
component: React.FunctionComponent
state: boolean
func: (bol: boolean) => IState
}
const useToggleButton = ({ on, off }: IToggleBntProps): IReturnType => {
const [toggle, setToggle] = React.useState(false)
const ToggleButton = () => (
<div
role="button"
onClick={() => setToggle(!toggle)}
data-testid="portal-toggle-btn"
>
{toggle ? on : off}
</div>
)
return [ToggleButton, toggle, setToggle]
}
export default useToggleButton
解决方案
TypeScript 实际上可以自动找出大多数这些类型!
在下面的代码中,在 return 语句末尾说as const
( a const assertion[() => JSX.Element, boolean, React.Dispatch<React.SetStateAction<boolean>>]
) 可以让 TypeScript 正确推断出你想要的返回类型:
如果你想明确一点,你可以这样做type IReturnType = [() => JSX.Element, boolean, React.Dispatch<React.SetStateAction<boolean>>]
,但那是冗长且不必要的。
interface IToggleBntProps {
on: any
off: any
}
const useToggleButton = ({ on, off }: IToggleBntProps) => {
const [toggle, setToggle] = React.useState(false)
const ToggleButton = () => (
<div
role="button"
onClick={() => setToggle(!toggle)}
data-testid="portal-toggle-btn"
>
{toggle ? on : off}
</div>
)
// saying 'as const' here means that TypeScript automatically
// knows that this should be a tuple type of three elements.
// Not you need TypeScript 3.4 or newer
return [ToggleButton, toggle, setToggle] as const;
}
export default useToggleButton
推荐阅读
- reactjs - 如何从库而不是 React 组件中调度 slice reducer
- java - ListView 内的 ImageButton onclick 列表器不起作用。应用点击后崩溃
- python - Matplotlib 绘制不存在的数据
- java - Java Mapstruct在调用时返回空指针
- sharepoint - 分享点唯一值
- node.js - Heroku 不允许将 Github 分支作为依赖项
- python - 如何在 Plotly Dash 中将 uirevision 直接添加到图形以进行自动更新
- gitlab-ci - Gitlab CI/CD 如何将标签设置为变量(由用户定义)
- html - thymeleaf :在 3 列中显示 n 个项目
- javascript - 注册链接到数据库并将数据放入管理表中的页面,并将我发送到主页