我可以使用 useRef 将对元素的引用传递给孩子吗？

Posted 2023-02-25

【中文标题】我可以使用 useRef 将对元素的引用传递给孩子吗？

【英文标题】：Can I use useRef to pass a reference to an element to a child?

【发布时间】：2020-06-30 09:20:59

【问题描述】：

我称我为查看器对象，它将某些东西安装到 ID 为 tgmlviewer 的元素中。当我只有一个这样的组件时，这很好用。

import React,  useEffect  from "react";
import  Viewer  from "../../tgmlViewer/Viewer";
import  disableTgmlPointerEvents  from "../../../constants";
import  XmlType  from "./XmlView";

type Props = 
  serialized: string;
  xmlType: XmlType;
;

const tgmlViewerId = "tgmlviewer";

export default function TgmlImageViewer(props: Props) 
  const  serialized, xmlType  = props;

  useEffect(() => 
    let viewer: Viewer;
    const viewerElement = document.getElementById(tgmlViewerId);
    if (viewerElement instanceof htmlDivElement) 
      viewer = new Viewer(viewerElement);
      viewer.load(serialized);
    
    return () => 
      if (viewer) 
        viewer.reset();
      
    ;
  );

  return (
    <div
      id=tgmlViewerId
    />
  );

现在我想创建多个组件。每个组件都需要将唯一的 id 传递给它的查看器对象。是否可以为此使用useRef？

这是我最好的尝试：

import React,  useEffect, useRef, Ref  from "react";
import  Viewer  from "../../tgmlViewer/Viewer";
import  disableTgmlPointerEvents  from "../../../constants";
import  XmlType  from "./XmlView";

type Props = 
  serialized: string;
  xmlType: XmlType;
;

export default function TgmlImageViewer(props: Props) 
  const  serialized, xmlType  = props;

  const tgmlViewerMountingTarget = useRef(null);

  useEffect(() => 
    if (!tgmlViewerMountingTarget) 
      return;
    
    let viewer: Viewer;
    const viewerElement = tgmlViewerMountingTarget.current;
    if (viewerElement instanceof HTMLDivElement) 
      viewer = new Viewer(viewerElement);
      viewer.load(serialized);
    
    return () => 
      if (viewer) 
        viewer.reset();
      
    ;
  );

  return (
    <div
      ref=tgmlViewerMountingTarget
    />
  );

TypeScript 错误

ts: const viewerElement: null // 'instanceof' 表达式的左侧必须是 'any' 类型、对象类型或类型参数。

【问题讨论】：

ref forwarding 不是您要找的东西吗？

我能够通过将类型传递给 useRef 函数来解决问题。 ref 转发会比 useRef 更好吗？

【参考方案1】：

改变

const tgmlViewerMountingTarget = useRef(null);

到

const tgmlViewerMountingTarget = useRef<HTMLDivElement>(null);