我为所有场合制定了解决方案。

你应该使用一个高阶组件来包装你想要监听的组件。

这个组件示例只有一个属性：“onClickedOutside”，它接收函数。

ClickedOutside.js

import React, { Component } from "react";

export default class ClickedOutside extends Component {
  componentDidMount() {
    document.addEventListener("mousedown", this.handleClickOutside);
  }

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

  handleClickOutside = event => {
    // IF exists the Ref of the wrapped component AND his dom children doesnt have the clicked component 
    if (this.wrapperRef && !this.wrapperRef.contains(event.target)) {
      // A props callback for the ClikedClickedOutside
      this.props.onClickedOutside();
    }
  };

  render() {
    // In this piece of code I'm trying to get to the first not functional component
    // Because it wouldn't work if use a functional component (like <Fade/> from react-reveal)
    let firstNotFunctionalComponent = this.props.children;
    while (typeof firstNotFunctionalComponent.type === "function") {
      firstNotFunctionalComponent = firstNotFunctionalComponent.props.children;
    }

    // Here I'm cloning the element because I have to pass a new prop, the "reference" 
    const children = React.cloneElement(firstNotFunctionalComponent, {
      ref: node => {
        this.wrapperRef = node;
      },
      // Keeping all the old props with the new element
      ...firstNotFunctionalComponent.props
    });

    return <React.Fragment>{children}</React.Fragment>;
  }
}

将onClick处理程序添加到顶级容器中，并在用户单击时增加状态值。将该值传递给相关组件，每当该值发生变化时，您就可以执行操作。

在本例中，每当clickCount值更改时，我们都会调用this.closeDropdown（）。

incrementClickCount方法在.app容器中激发，而不是在下拉列表中激发，因为我们使用event.stopPropagation（）来防止事件冒泡。

您的代码可能最终看起来像这样：

class App extends Component {
    constructor(props) {
        super(props);
        this.state = {
            clickCount: 0
        };
    }
    incrementClickCount = () => {
        this.setState({
            clickCount: this.state.clickCount + 1
        });
    }
    render() {
        return (
            <div className="app" onClick={this.incrementClickCount}>
                <Dropdown clickCount={this.state.clickCount}/>
            </div>
        );
    }
}
class Dropdown extends Component {
    constructor(props) {
        super(props);
        this.state = {
            open: false
        };
    }
    componentDidUpdate(prevProps) {
        if (this.props.clickCount !== prevProps.clickCount) {
            this.closeDropdown();
        }
    }
    toggleDropdown = event => {
        event.stopPropagation();
        return (this.state.open) ? this.closeDropdown() : this.openDropdown();
    }
    render() {
        return (
            <div className="dropdown" onClick={this.toggleDropdown}>
                ...
            </div>
        );
    }
}

我知道这是一个老问题，但我不断遇到这个问题，我很难用简单的格式来解决这个问题。所以，如果这能让任何人的生活变得轻松一点，请使用airbnb的OutsideClickHandler。这是一个最简单的插件，无需编写自己的代码即可完成此任务。

例子：

hideresults(){
   this.setState({show:false})
}
render(){
 return(
 <div><div onClick={() => this.setState({show:true})}>SHOW</div> {(this.state.show)? <OutsideClickHandler onOutsideClick={() => 
  {this.hideresults()}} > <div className="insideclick"></div> </OutsideClickHandler> :null}</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();
                                        }}/>

`

非侵入性方式无需添加另一个DIV EL。

注意：React可能会说findDomNode已弃用，但到目前为止，我还没有遇到任何问题

@异常：单击要忽略的类

@idException:单击时忽略的id

import React from "react"
import ReactDOM from "react-dom"
type Func1<T1, R> = (a1: T1) => R


export function closest(
    el: Element,
    fn: (el: Element) => boolean
  ): Element | undefined {
    let el_: Element | null = el;
  
    while (el_) {
      if (fn(el_)) {
        return el_;
      }
  
      el_ = el_.parentElement;
    }
  }
let instances: ClickOutside[] = []

type Props = {
  idException?: string,
  exceptions?: (string | Func1<MouseEvent, boolean>)[]
  handleClickOutside: Func1<MouseEvent, void>

}


export default class ClickOutside extends React.Component<Props> {
  static defaultProps = {
    exceptions: []
  };

  componentDidMount() {
    if (instances.length === 0) {
      document.addEventListener("mousedown", this.handleAll, true)
      window.parent.document.addEventListener(
        "mousedown",
        this.handleAll,
        true
      )
    }
    instances.push(this)
  }

  componentWillUnmount() {
    instances.splice(instances.indexOf(this), 1)
    if (instances.length === 0) {
      document.removeEventListener("mousedown", this.handleAll, true)
      window.parent.document.removeEventListener(
        "mousedown",
        this.handleAll,
        true
      )
    }
  }

  handleAll = (e: MouseEvent) => {

    const target: HTMLElement = e.target as HTMLElement
    if (!target) return

    instances.forEach(instance => {
      const { exceptions, handleClickOutside: onClickOutside, idException } = instance.props as Required<Props>
      let exceptionsCount = 0

      if (exceptions.length > 0) {
        const { functionExceptions, stringExceptions } = exceptions.reduce(
          (acc, exception) => {
            switch (typeof exception) {
              case "function":
                acc.functionExceptions.push(exception)
                break
              case "string":
                acc.stringExceptions.push(exception)
                break
            }

            return acc
          },
          { functionExceptions: [] as Func1<MouseEvent, boolean>[], stringExceptions: [] as string[] }
        )
        if (functionExceptions.length > 0) {
          exceptionsCount += functionExceptions.filter(
            exception => exception(e) === true
          ).length
        }

        if (exceptionsCount === 0 && stringExceptions.length > 0) {

          const el = closest(target, (e) => stringExceptions.some(ex => e.classList.contains(ex)))
          if (el) {
            exceptionsCount++
          }
        }
      }

      if (idException) {
        const target = e.target as HTMLDivElement
        if (document.getElementById(idException)!.contains(target)) {
          exceptionsCount++
        }
      }

      if (exceptionsCount === 0) {
        // eslint-disable-next-line react/no-find-dom-node
        const node = ReactDOM.findDOMNode(instance)

        if (node && !node.contains(target)) {
          onClickOutside(e)
        }
      }
    })
  };

  render() {
    return React.Children.only(this.props.children)
  }
}

用法

<ClickOutside {...{ handleClickOutside: () => { alert('Clicked Outside') } }}>
    <div >
        <div>Breathe</div>
    </div>
</ClickOutside>

因为对我来说！ref.current.contains（e.target）无法工作，因为ref中包含的DOM元素正在更改，我提出了一个稍微不同的解决方案：

function useClickOutside<T extends HTMLElement>(
  element: T | null,
  onClickOutside: () => void,
) {
  useEffect(() => {
    function handleClickOutside(event: MouseEvent) {
      const xCoord = event.clientX;
      const yCoord = event.clientY;

      if (element) {
        const { right, x, bottom, y } = element.getBoundingClientRect();
        if (xCoord < right && xCoord > x && yCoord < bottom && yCoord > y) {
          return;
        }

        onClickOutside();
      }
    }

    document.addEventListener('click', handleClickOutside);
    return () => {
      document.removeEventListener('click', handleClickOutside);
    };
  }, [element, onClickOutside]);