javascript - 如何引用组件并监听外部点击？

Question

所以我正在尝试制作下拉选项组件。我想通过单击按钮来显示它，如果在此组件之外检测到单击，则将其隐藏。

这是一个代码。我做了 ref，但我不明白如何检查点击是否在组件上:

import React, { Component } from 'react'
import './OptionsMenu.sass'

import DropdownBox from '../DropdownBox/DropdownBox'
import Icon from '../Icon/Icon'

class OptionsMenu extends Component {
    constructor(){
        super()
        this.dropdownBoxRef = React.createRef()
    }

  handleClickOutside = event => {
    if (this.dropdownBoxRef && !this.dropdownBoxRef.contains(event.target)) {
      this.props.close()
    }
  }

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

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

  render() {
    const options = this.props.options.map(option => (
      <li className='OptionsList-Element'>
        <div className='OptionsList-ElementIcon'>
          <Icon name={option.icon} />
        </div>
        <span>{option.label}</span>
      </li>
    ))
    return (
      <DropdownBox ref={this.dropdownBoxRef} styles={this.props.styles}>
        <ul className='OptionsList'>{options}</ul>
      </DropdownBox>
    )
  }
}

export default OptionsMenu

使用这段代码我有错误:OptionsMenu.js:14 Uncaught TypeError: _this.dropdownBoxRef.contains 不是函数

我知道错误，因为它没有 .contains()。那么我必须尝试使用​​什么？

Answer 1

请找到有助于解决您的问题的更新代码:

import ReactDOM from "react-dom";

import "./styles.css";
import React, { Component } from "react";

class OptionsMenu extends Component {
  constructor() {
    super();
    this.dropdownBoxRef = React.createRef();
  }

  handleClickOutside = event => {
    if (this.dropdownBoxRef && !this.dropdownBoxRef.current.contains(event.target)) {
      this.props.close();
    }
  };

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

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

  render() {
    const options = ["a", "b", "c"].map(option => (
      <li className="OptionsList-Element">
        <div className="OptionsList-ElementIcon">Icon</div>
        <span>{option.label}</span>
      </li>
    ));
    return (
      <div ref={this.dropdownBoxRef} styles={this.props.styles}>
        <ul className="OptionsList">{options}</ul>
      </div>
    );
  }
}

export default OptionsMenu;

const rootElement = document.getElementById("root");
ReactDOM.render(<OptionsMenu />, rootElement);

注意:this.dropdownBoxRef.current.contains(event.target) 行是游戏规则的改变者。