我之所以这样做，部分原因是遵循了这一点，并遵循了React官方文件关于处理需要React ^16.3的参考文献。这是我在尝试了其他一些建议之后唯一有效的方法。。。

class App extends Component {
  constructor(props) {
    super(props);
    this.inputRef = React.createRef();
  }
  componentWillMount() {
    document.addEventListener("mousedown", this.handleClick, false);
  }
  componentWillUnmount() {
    document.removeEventListener("mousedown", this.handleClick, false);
  }
  handleClick = e => {
    /*Validating click is made inside a component*/
    if ( this.inputRef.current === e.target ) {
      return;
    }
    this.handleclickOutside();
  };
  handleClickOutside(){
    /*code to handle what to do when clicked outside*/
  }
  render(){
    return(
      <div>
        <span ref={this.inputRef} />
      </div>
    )
  }
}

在我的DROPDOWN案例中，Ben Bud的解决方案工作得很好，但我有一个单独的切换按钮和一个onClick处理程序。因此，外部单击逻辑与单击切换按钮冲突。下面是我如何通过传递按钮的ref来解决这个问题：

import React, { useRef, useEffect, useState } from "react";

/**
 * Hook that triggers onClose when clicked outside of ref and buttonRef elements
 */
function useOutsideClicker(ref, buttonRef, onOutsideClick) {
  useEffect(() => {

    function handleClickOutside(event) {
      /* clicked on the element itself */
      if (ref.current && !ref.current.contains(event.target)) {
        return;
      }

      /* clicked on the toggle button */
      if (buttonRef.current && !buttonRef.current.contains(event.target)) {
        return;
      }

      /* If it's something else, trigger onClose */
      onOutsideClick();
    }

    // Bind the event listener
    document.addEventListener("mousedown", handleClickOutside);
    return () => {
      // Unbind the event listener on clean up
      document.removeEventListener("mousedown", handleClickOutside);
    };
  }, [ref]);
}

/**
 * Component that alerts if you click outside of it
 */
export default function DropdownMenu(props) {
  const wrapperRef = useRef(null);
  const buttonRef = useRef(null);
  const [dropdownVisible, setDropdownVisible] = useState(false);

  useOutsideClicker(wrapperRef, buttonRef, closeDropdown);

  const toggleDropdown = () => setDropdownVisible(visible => !visible);

  const closeDropdown = () => setDropdownVisible(false);

  return (
    <div>
      <button onClick={toggleDropdown} ref={buttonRef}>Dropdown Toggler</button>
      {dropdownVisible && <div ref={wrapperRef}>{props.children}</div>}
    </div>
  );
}

对于那些需要绝对定位的人，我选择的一个简单选项是添加一个包装器组件，该组件的样式是以透明背景覆盖整个页面。然后可以在这个元素上添加一个onClick来关闭内部组件。

<div style={{
        position: 'fixed',
        top: '0', right: '0', bottom: '0', left: '0',
        zIndex: '1000',
      }} onClick={() => handleOutsideClick()} >
    <Content style={{position: 'absolute'}}/>
</div>

现在，如果您在内容上添加一个单击处理程序，那么事件也将传播到上面的div，从而触发handlerOutsideClick。如果这不是您想要的行为，只需停止处理程序上的事件进程。

<Content style={{position: 'absolute'}} onClick={e => {
                                          e.stopPropagation();
                                          desiredFunctionCall();
                                        }}/>

`

基于Tanner Linsley在2020年夏威夷联合会议上的精彩演讲：

使用OuterClick API

const Client = () => {
  const innerRef = useOuterClick(ev => {/*event handler code on outer click*/});
  return <div ref={innerRef}> Inside </div> 
};

实施

function useOuterClick(callback) {
  const callbackRef = useRef(); // initialize mutable ref, which stores callback
  const innerRef = useRef(); // returned to client, who marks "border" element

  // update cb on each render, so second useEffect has access to current value 
  useEffect(() => { callbackRef.current = callback; });
  
  useEffect(() => {
    document.addEventListener("click", handleClick);
    return () => document.removeEventListener("click", handleClick);
    function handleClick(e) {
      if (innerRef.current && callbackRef.current && 
        !innerRef.current.contains(e.target)
      ) callbackRef.current(e);
    }
  }, []); // no dependencies -> stable click listener
      
  return innerRef; // convenience for client (doesn't need to init ref himself) 
}

下面是一个工作示例：

/*自定义挂钩*/函数useOuterClick（回调）{const innerRef=useRef（）；const callbackRef=useRef（）；//在ref中设置当前回调，然后第二个useEffect使用它useEffect（（）=>{//useEffect包装器对于并发模式是安全的callbackRef.current=回调；});使用效果（（）=>{document.addEventListener（“单击”，handleClick）；return（）=>document.removeEventListener（“单击”，handleClick）；//从ref中读取最近的回调和innerRefdom节点函数句柄Click（e）{如果(内部参考当前&&回调参考当前&&!innerRef.current.contains（e.target）) {callbackRef.current（e）；}}}, []); // 无需回调+innerRef-depreturn innerRef；//返回参考；客户端可以省略`useRef`}/*用法*/常量客户端=（）=>{const[counter，setCounter]=useState（0）；const innerRef=useOuterClick（e=>{//调用处理程序时，计数器状态是最新的alert（`Clicked outside！Increment counter to${counter+1｝`）；设置计数器（c=>c+1）；});返回(＜div＞<p>点击外面</p＞<div id=“container”ref={innerRef}>内部，计数器：｛counter｝</div></div>);};ReactDOM.render（<Client/>，document.getElementById（“root”））；#容器｛边框：1px纯红色；填充：20px；｝<script src=“https://cdnjs.cloudflare.com/ajax/libs/react/16.12.0/umd/react.production.min.js“integrity=”sha256-Ef0vObdWpkMAnxp39TYSLVS/vVUokDE8CDFnx7tjY6U=“crossrorigin=”匿名“></script><script src=“https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.12.0/umd/react-dom.production.min.js“integrity=”sha256-p2yuFdE8hNZsQ31Qk+s8N+Me2fL5cc6NKXOC0U9uGw=“crossrorigin=”匿名“></script><script>var｛useRef，useEffect，useCallback，useState｝=反应</script><div id=“root”></div>

要点

useOuterClick利用可变引用提供瘦客户端API包含组件（[]deps）的生命周期的稳定单击侦听器客户端可以设置回调，而无需使用callback将其记忆回调主体可以访问最新的属性和状态-没有过时的闭包值

（iOS的侧注）

iOS通常只将某些元素视为可点击的。要使外部单击有效，请选择一个不同于文档的单击侦听器-不向上包括正文。例如，在React根div上添加一个监听器，并扩展其高度，如height:100vh，以捕捉所有外部点击。来源：quicksmod.org

带钩的字体

注意：我使用的是React 16.3版，带有React.createRef。对于其他版本，使用ref回调。

下拉组件：

interface DropdownProps {
 ...
};

export const Dropdown: React.FC<DropdownProps> () {
  const ref: React.RefObject<HTMLDivElement> = React.createRef();
  
  const handleClickOutside = (event: MouseEvent) => {
    if (ref && ref !== null) {
      const cur = ref.current;
      if (cur && !cur.contains(event.target as Node)) {
        // close all dropdowns
      }
    }
  }

  useEffect(() => {
    // Bind the event listener
    document.addEventListener("mousedown", handleClickOutside);
    return () => {
      // Unbind the event listener on clean up
      document.removeEventListener("mousedown", handleClickOutside);
    };
  });

  return (
    <div ref={ref}>
        ...
    </div>
  );
}

以下解决方案使用ES6并遵循绑定以及通过方法设置ref的最佳实践。

要将其付诸行动：

挂钩实施反应16.3后的类实现反应16.3之前的类实现

挂钩实施：

import React, { useRef, useEffect } from "react";

/**
 * Hook that alerts clicks outside of the passed ref
 */
function useOutsideAlerter(ref) {
  useEffect(() => {
    /**
     * Alert if clicked on outside of element
     */
    function handleClickOutside(event) {
      if (ref.current && !ref.current.contains(event.target)) {
        alert("You clicked outside of me!");
      }
    }
    // Bind the event listener
    document.addEventListener("mousedown", handleClickOutside);
    return () => {
      // Unbind the event listener on clean up
      document.removeEventListener("mousedown", handleClickOutside);
    };
  }, [ref]);
}

/**
 * Component that alerts if you click outside of it
 */
export default function OutsideAlerter(props) {
  const wrapperRef = useRef(null);
  useOutsideAlerter(wrapperRef);

  return <div ref={wrapperRef}>{props.children}</div>;
}

类实现：

16.3之后

import React, { Component } from "react";

/**
 * Component that alerts if you click outside of it
 */
export default class OutsideAlerter extends Component {
  constructor(props) {
    super(props);

    this.wrapperRef = React.createRef();
    this.handleClickOutside = this.handleClickOutside.bind(this);
  }

  componentDidMount() {
    document.addEventListener("mousedown", this.handleClickOutside);
  }

  componentWillUnmount() {
    document.removeEventListener("mousedown", this.handleClickOutside);
  }

  /**
   * Alert if clicked on outside of element
   */
  handleClickOutside(event) {
    if (this.wrapperRef && !this.wrapperRef.current.contains(event.target)) {
      alert("You clicked outside of me!");
    }
  }

  render() {
    return <div ref={this.wrapperRef}>{this.props.children}</div>;
  }
}

16.3之前

import React, { Component } from "react";

/**
 * Component that alerts if you click outside of it
 */
export default class OutsideAlerter extends Component {
  constructor(props) {
    super(props);

    this.setWrapperRef = this.setWrapperRef.bind(this);
    this.handleClickOutside = this.handleClickOutside.bind(this);
  }

  componentDidMount() {
    document.addEventListener("mousedown", this.handleClickOutside);
  }

  componentWillUnmount() {
    document.removeEventListener("mousedown", this.handleClickOutside);
  }

  /**
   * Set the wrapper ref
   */
  setWrapperRef(node) {
    this.wrapperRef = node;
  }

  /**
   * Alert if clicked on outside of element
   */
  handleClickOutside(event) {
    if (this.wrapperRef && !this.wrapperRef.contains(event.target)) {
      alert("You clicked outside of me!");
    }
  }

  render() {
    return <div ref={this.setWrapperRef}>{this.props.children}</div>;
  }
}