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>

[更新]使用挂钩的React ^16.8解决方案

代码沙盒

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

const SampleComponent = () => {
    const [clickedOutside, setClickedOutside] = useState(false);
    const myRef = useRef();

    const handleClickOutside = e => {
        if (!myRef.current.contains(e.target)) {
            setClickedOutside(true);
        }
    };

    const handleClickInside = () => setClickedOutside(false);

    useEffect(() => {
        document.addEventListener('mousedown', handleClickOutside);
        return () => document.removeEventListener('mousedown', handleClickOutside);
    });

    return (
        <button ref={myRef} onClick={handleClickInside}>
            {clickedOutside ? 'Bye!' : 'Hello!'}
        </button>
    );
};

export default SampleComponent;

反应溶液^16.3：

代码沙盒

import React, { Component } from "react";

class SampleComponent extends Component {
  state = {
    clickedOutside: false
  };

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

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

  myRef = React.createRef();

  handleClickOutside = e => {
    if (!this.myRef.current.contains(e.target)) {
      this.setState({ clickedOutside: true });
    }
  };

  handleClickInside = () => this.setState({ clickedOutside: false });

  render() {
    return (
      <button ref={this.myRef} onClick={this.handleClickInside}>
        {this.state.clickedOutside ? "Bye!" : "Hello!"}
      </button>
    );
  }
}

export default SampleComponent;

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>
  );
}

我对所有其他答案最担心的是必须从根/父级向下过滤单击事件。我发现最简单的方法是简单地设置一个具有位置的同级元素：fixed，下拉列表后面的z索引1，并处理同一组件内固定元素上的单击事件。将所有内容集中到给定组件。

示例代码

#HTML
<div className="parent">
  <div className={`dropdown ${this.state.open ? open : ''}`}>
    ...content
  </div>
  <div className="outer-handler" onClick={() => this.setState({open: false})}>
  </div>
</div>

#SASS
.dropdown {
  display: none;
  position: absolute;
  top: 0px;
  left: 0px;
  z-index: 100;
  &.open {
    display: block;
  }
}
.outer-handler {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0;
    z-index: 99;
    display: none;
    &.open {
      display: block;
    }
}

除了.concurs之外，还可以使用最接近的方法。当您想检查单击是否在id=“apple”的元素之外时，我可以使用：

const isOutside = !e.target.closest("#apple");

这将检查单击的树上方的树中是否有任何元素的id为“apple”。我们必须否定结果！

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>
    )
  }
}