forwardRef/createRef

查看 Hooks 部分 以了解 useRef。

createRef:

import { createRef, PureComponent } from "react";

class CssThemeProvider extends PureComponent<Props> {
  private rootRef = createRef<HTMLDivElement>(); // like this
  render() {
    return <div ref={this.rootRef}>{this.props.children}</div>;
  }
}

forwardRef:

import { forwardRef, ReactNode } from "react";

interface Props {
  children?: ReactNode;
  type: "submit" | "button";
}
export type Ref = HTMLButtonElement;

export const FancyButton = forwardRef<Ref, Props>((props, ref) => (
  <button ref={ref} className="MyClassName" type={props.type}>
    {props.children}
  </button>
));

旁注：从 forwardRef 获取的 ref 是可变的，因此如果需要，可以对其进行赋值。

这是 有意为之。如果必须，可以使其不可变 - 如果您希望确保没有人重新分配它，则分配 React.Ref

import { forwardRef, ReactNode, Ref } from "react";

interface Props {
  children?: ReactNode;
  type: "submit" | "button";
}

export const FancyButton = forwardRef(
  (
    props: Props,
    ref: Ref<HTMLButtonElement> // <-- here!
  ) => (
    <button ref={ref} className="MyClassName" type={props.type}>
      {props.children}
    </button>
  )
);

如果您要获取转发 ref 的组件的 props，请使用 ComponentPropsWithRef。

泛型 forwardRefs

在 https://fettblog.eu/typescript-react-generic-forward-refs/ 中阅读更多上下文。

选项 1 - 包装器组件

type ClickableListProps<T> = {
  items: T[];
  onSelect: (item: T) => void;
  mRef?: React.Ref<HTMLUListElement> | null;
};

export function ClickableList<T>(props: ClickableListProps<T>) {
  return (
    <ul ref={props.mRef}>
      {props.items.map((item, i) => (
        <li key={i}>
          <button onClick={(el) => props.onSelect(item)}>Select</button>
          {item}
        </li>
      ))}
    </ul>
  );
}

选项 2 - 重新声明 forwardRef

// Redeclare forwardRef
declare module "react" {
  function forwardRef<T, P = {}>(
    render: (props: P, ref: React.Ref<T>) => React.ReactElement | null
  ): (props: P & React.RefAttributes<T>) => React.ReactElement | null;
}

// Just write your components like you're used to!
import { forwardRef, ForwardedRef } from "react";

interface ClickableListProps<T> {
  items: T[];
  onSelect: (item: T) => void;
}

function ClickableListInner<T>(
  props: ClickableListProps<T>,
  ref: ForwardedRef<HTMLUListElement>
) {
  return (
    <ul ref={ref}>
      {props.items.map((item, i) => (
        <li key={i}>
          <button onClick={(el) => props.onSelect(item)}>Select</button>
          {item}
        </li>
      ))}
    </ul>
  );
}

export const ClickableList = forwardRef(ClickableListInner);

选项 3 - 调用签名

// Add to `index.d.ts`
interface ForwardRefWithGenerics extends React.FC<WithForwardRefProps<Option>> {
  <T extends Option>(props: WithForwardRefProps<T>): ReturnType<
    React.FC<WithForwardRefProps<T>>
  >;
}

export const ClickableListWithForwardRef: ForwardRefWithGenerics =
  forwardRef(ClickableList);

鸣谢： https://stackoverflow.com/a/73795494

更多信息

• https://medium.com/@martin_hotell/react-refs-with-typescript-a32d56c4d315

您可能还希望使用 forwardRef 进行条件渲染。

有需要补充的内容？提交问题.