@lynx-js/react / PureComponent

#类: PureComponent<P, S, SS>

#继承

• Component<P, S, SS>

#类型参数

#构造函数

#new PureComponent()

new PureComponent<P, S, SS>(props: P): PureComponent<P, S, SS>

#参数

#返回

PureComponent<P, S, SS>

#继承自

Component.constructor

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1017

#new PureComponent()

new PureComponent<P, S, SS>(props: P, context: any): PureComponent<P, S, SS>

#参数

#返回

PureComponent<P, S, SS>

#已被弃用

#参阅

React Docs

#继承自

Component.constructor

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1022

#属性

#context

context: unknown;

If using the new style context, re-declare this in your class to be the React.ContextType of your static contextType. Should be used with type annotation or static contextType.

#示例

static contextType = MyContext
// For TS pre-3.7:
context!: React.ContextType<typeof MyContext>
// For TS 3.7 and above:
declare context: React.ContextType<typeof MyContext>

#参阅

React Docs

#继承自

Component.context

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1015

#props

readonly props: Readonly<P>;

#继承自

Component.props

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1035

#refs

refs: object;

#索引签名

[key: string]: ReactInstance

#已被弃用

#参阅

Legacy React Docs

#继承自

Component.refs

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1042

#state

state: Readonly<S>;

#继承自

Component.state

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1036

#contextType?

static optional contextType: Context<any>;

If set, this.context will be set at runtime to the current value of the given Context.

#示例

type MyContext = number
const Ctx = React.createContext<MyContext>(0)

class Foo extends React.Component {
  static contextType = Ctx
  context!: React.ContextType<typeof Ctx>
  render () {
    return <>My context's value: {this.context}</>;
  }
}

#参阅

https://react.dev/reference/react/Component#static-contexttype

#继承自

Component.contextType

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:997

#方法

#componentDidCatch()?

optional componentDidCatch(error: Error, errorInfo: ErrorInfo): void

Catches exceptions generated in descendant components. Unhandled exceptions will cause the entire component tree to unmount.

#参数

#返回

void

#继承自

Component.componentDidCatch

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1399

#componentDidMount()?

optional componentDidMount(): void

Called immediately after a component is mounted. Setting state here will trigger re-rendering.

#返回

void

#继承自

Component.componentDidMount

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1378

#componentDidUpdate()?

optional componentDidUpdate(
   prevProps: Readonly<P>, 
   prevState: Readonly<S>, 
   snapshot?: SS): void

Called immediately after updating occurs. Not called for the initial render.

The snapshot is only present if getSnapshotBeforeUpdate is present and returns non-null.

#参数

#返回

void

#继承自

Component.componentDidUpdate

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1441

#componentWillMount()?

optional componentWillMount(): void

Called immediately before mounting occurs, and before Component.render. Avoid introducing any side-effects or subscriptions in this method.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

#返回

void

#已被弃用

16.3, use ComponentLifecycle.componentDidMount componentDidMount or the constructor instead; will stop working in React 17

#参阅

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#initializing-state
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

#继承自

Component.componentWillMount

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1457

#componentWillReceiveProps()?

optional componentWillReceiveProps(nextProps: Readonly<P>, nextContext: any): void

Called when the component may be receiving new props. React may call this even if props have not changed, so be sure to compare new and existing props if you only want to handle changes.

Calling Component.setState generally does not trigger this method.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

#参数

#返回

void

#已被弃用

16.3, use static StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps instead; will stop working in React 17

#参阅

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#updating-state-based-on-props
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

#继承自

Component.componentWillReceiveProps

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1488

#componentWillUnmount()?

optional componentWillUnmount(): void

Called immediately before a component is destroyed. Perform any necessary cleanup in this method, such as cancelled network requests, or cleaning up any DOM elements created in componentDidMount.

#返回

void

#继承自

Component.componentWillUnmount

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1394

#componentWillUpdate()?

optional componentWillUpdate(
   nextProps: Readonly<P>, 
   nextState: Readonly<S>, 
   nextContext: any): void

Called immediately before rendering when new props or state is received. Not called for the initial render.

Note: You cannot call Component.setState here.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

#参数

#返回

void

#已被弃用

16.3, use getSnapshotBeforeUpdate instead; will stop working in React 17

#参阅

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#reading-dom-properties-before-an-update
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

#继承自

Component.componentWillUpdate

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1520

#forceUpdate()

forceUpdate(callback?: () => void): void

#参数

#返回

void

#继承自

Component.forceUpdate

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1032

#getSnapshotBeforeUpdate()?

optional getSnapshotBeforeUpdate(prevProps: Readonly<P>, prevState: Readonly<S>): null | SS

Runs before React applies the result of render to the document, and returns an object to be given to componentDidUpdate. Useful for saving things such as scroll position before render causes changes to it.

Note: the presence of this method prevents any of the deprecated lifecycle events from running.

#参数

#返回

null | SS

#继承自

Component.getSnapshotBeforeUpdate

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1435

#render()

render(): ReactNode

#返回

ReactNode

#继承自

Component.render

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1033

#setState()

setState<K>(state: null | S | (prevState: Readonly<S>, props: Readonly<P>) => null | S | Pick<S, K> | Pick<S, K>, callback?: () => void): void

#类型参数

#参数

#返回

void

#继承自

Component.setState

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1027

#shouldComponentUpdate()?

optional shouldComponentUpdate(
   nextProps: Readonly<P>, 
   nextState: Readonly<S>, 
   nextContext: any): boolean

Called to determine whether the change in props and state should trigger a re-render.

Component always returns true. PureComponent implements a shallow comparison on props and state and returns true if any props or states have changed.

If false is returned, Component.render, componentWillUpdate and componentDidUpdate will not be called.

#参数

#返回

boolean

#继承自

Component.shouldComponentUpdate

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1389

#UNSAFE_componentWillMount()?

optional UNSAFE_componentWillMount(): void

Called immediately before mounting occurs, and before Component.render. Avoid introducing any side-effects or subscriptions in this method.

This method will not stop working in React 17.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

#返回

void

#已被弃用

16.3, use ComponentLifecycle.componentDidMount componentDidMount or the constructor instead

#参阅

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#initializing-state
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

#继承自

Component.UNSAFE_componentWillMount

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1472

#UNSAFE_componentWillReceiveProps()?

optional UNSAFE_componentWillReceiveProps(nextProps: Readonly<P>, nextContext: any): void

Called when the component may be receiving new props. React may call this even if props have not changed, so be sure to compare new and existing props if you only want to handle changes.

Calling Component.setState generally does not trigger this method.

This method will not stop working in React 17.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

#参数

#返回

void

#已被弃用

16.3, use static StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps instead

#参阅

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#updating-state-based-on-props
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

#继承自

Component.UNSAFE_componentWillReceiveProps

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1506

#UNSAFE_componentWillUpdate()?

optional UNSAFE_componentWillUpdate(
   nextProps: Readonly<P>, 
   nextState: Readonly<S>, 
   nextContext: any): void

Called immediately before rendering when new props or state is received. Not called for the initial render.

Note: You cannot call Component.setState here.

This method will not stop working in React 17.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

#参数

#返回

void

#已被弃用

16.3, use getSnapshotBeforeUpdate instead

#参阅

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#reading-dom-properties-before-an-update
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

#继承自

Component.UNSAFE_componentWillUpdate

#定义于

.pnpm/@types+react@18.3.28/node_modules/@types/react/ts5.0/index.d.ts:1536