以上答案中没有一个对我有效，所以我最终做了如下：

从“React”导入React，｛Component｝；

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

    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 (!event.path || !event.path.filter(item => item.className=='classOfAComponent').length) {
      alert('You clicked outside of me!');
    }
  }

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

OutsideAlerter.propTypes = {
  children: PropTypes.element.isRequired,
};

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。

如果您需要typescript版本：

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

interface Props {
  ref: React.MutableRefObject<any>;

}

export const useOutsideAlerter = ({ ref }: Props) => {
  useEffect(() => {
    const handleClickOutside = (event: MouseEvent) => {
      if (ref.current && !ref.current.contains(event.target as Node)) {
       //do what ever you want
      }
    };
    // Bind the event listener
    document.addEventListener("mousedown", handleClickOutside);
    return () => {
      // Unbind the event listener on clean up
      document.removeEventListener("mousedown", handleClickOutside);
    };
  }, [ref]);
};
export default useOutsideAlerter;

如果您想扩展它以关闭模态或隐藏某些内容，也可以执行以下操作：

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

interface Props {
  ref: React.MutableRefObject<any>;
  setter: React.Dispatch<React.SetStateAction<boolean>>;
}

export const useOutsideAlerter = ({ ref, setter }: Props) => {
  useEffect(() => {
    const handleClickOutside = (event: MouseEvent) => {
      if (ref.current && !ref.current.contains(event.target as Node)) {
        setter(false);
      }
    };
    // Bind the event listener
    document.addEventListener("mousedown", handleClickOutside);
    return () => {
      // Unbind the event listener on clean up
      document.removeEventListener("mousedown", handleClickOutside);
    };
  }, [ref, setter]);
};
export default useOutsideAlerter;

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;
    }
}

要使“焦点”解决方案适用于带有事件侦听器的下拉列表，您可以使用onMouseDown事件而不是onClick来添加它们。这样，事件将启动，之后弹出窗口将关闭，如下所示：

<TogglePopupButton
                    onClick = { this.toggleDropup }
                    tabIndex = '0'
                    onBlur = { this.closeDropup }
                />
                { this.state.isOpenedDropup &&
                <ul className = { dropupList }>
                    { this.props.listItems.map((item, i) => (
                        <li
                            key = { i }
                            onMouseDown = { item.eventHandler }
                        >
                            { item.itemName}
                        </li>
                    ))}
                </ul>
                }

@ford04提案的字体+简化版：

使用OuterClick API

const Client = () => {
  const ref = useOuterClick<HTMLDivElement>(e => { /* Custom-event-handler */ });
  return <div ref={ref}> Inside </div> 
};

实施

export default function useOuterClick<T extends HTMLElement>(callback: Function) {
  const callbackRef = useRef<Function>(); // initialize mutable ref, which stores callback
  const innerRef = useRef<T>(null); // 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", _onClick);
    return () => document.removeEventListener("click", _onClick);
    function _onClick(e: any): void {
      const clickedOutside = !(innerRef.current?.contains(e.target));
      if (clickedOutside)
        callbackRef.current?.(e);
    }
  }, []); // no dependencies -> stable click listener

  return innerRef; // convenience for client (doesn't need to init ref himself)
}