我被困在同一个问题上。我参加这里的聚会有点晚了，但对我来说，这是一个非常好的解决方案。希望这对其他人有帮助。您需要从react dom导入findDOMNode

import ReactDOM from 'react-dom';
// ... ✂

componentDidMount() {
    document.addEventListener('click', this.handleClickOutside, true);
}

componentWillUnmount() {
    document.removeEventListener('click', this.handleClickOutside, true);
}

handleClickOutside = event => {
    const domNode = ReactDOM.findDOMNode(this);

    if (!domNode || !domNode.contains(event.target)) {
        this.setState({
            visible: false
        });
    }
}

反应挂钩法（16.8+）

您可以创建一个名为useComponentVisible的可重用钩子。

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

export default function useComponentVisible(initialIsVisible) {
    const [isComponentVisible, setIsComponentVisible] = useState(initialIsVisible);
    const ref = useRef(null);

    const handleClickOutside = (event) => {
        if (ref.current && !ref.current.contains(event.target)) {
            setIsComponentVisible(false);
        }
    };

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

    return { ref, isComponentVisible, setIsComponentVisible };
}

然后在组件中添加功能以执行以下操作：

const DropDown = () => {
    const { ref, isComponentVisible } = useComponentVisible(true);
    return (
       <div ref={ref}>
          {isComponentVisible && (<p>Dropdown Component</p>)}
       </div>
    );
 
}

在这里查找codesandbox示例。

或者：

const onClickOutsideListener = () => {
    alert("click outside")
    document.removeEventListener("click", onClickOutsideListener)
  }

...

return (
  <div
    onMouseLeave={() => {
          document.addEventListener("click", onClickOutsideListener)
        }}
  >
   ...
  </div>

在这里尝试了许多方法之后，我决定使用github.com/Pomax/react-onclickoutside，因为它非常完整。

我通过npm安装了模块并将其导入到组件中：

import onClickOutside from 'react-onclickoutside'

然后，在组件类中，我定义了handleClickOutside方法：

handleClickOutside = () => {
  console.log('onClickOutside() method called')
}

导出组件时，我将其包装在onClickOutside（）中：

export default onClickOutside(NameOfComponent)

就是这样。

我喜欢@Ben Bud的答案，但当有视觉上嵌套的元素时，contains（event.target）并不能像预期的那样工作。

因此，有时最好计算点击点是否位于元素内部。

这是我的React Hook代码。

import { useEffect } from 'react'

export function useOnClickRectOutside(ref, handler) {
  useEffect(() => {
    const listener = (event) => {
      const targetEl = ref.current
      if (targetEl) {
        const clickedX = event.clientX
        const clickedY = event.clientY
        const rect = targetEl.getBoundingClientRect()
        const targetElTop = rect.top
        const targetElBottom = rect.top + rect.height
        const targetElLeft = rect.left
        const targetElRight = rect.left + rect.width

        if (
          // check X Coordinate
          targetElLeft < clickedX &&
          clickedX < targetElRight &&
          // check Y Coordinate
          targetElTop < clickedY &&
          clickedY < targetElBottom
        ) {
          return
        }

        // trigger event when the clickedX,Y is outside of the targetEl
        handler(event)
      }
    }

    document.addEventListener('mousedown', listener)
    document.addEventListener('touchstart', listener)

    return () => {
      document.removeEventListener('mousedown', listener)
      document.removeEventListener('touchstart', listener)
    }
  }, [ref, handler])
}

componentWillMount(){

  document.addEventListener('mousedown', this.handleClickOutside)
}

handleClickOutside(event) {

  if(event.path[0].id !== 'your-button'){
     this.setState({showWhatever: false})
  }
}

事件路径[0]是最后单击的项目

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>;
  }
}