我正在寻找一种方法来检测单击事件是否发生在组件之外,如本文所述。jQueryclosest()用于查看单击事件的目标是否将dom元素作为其父元素之一。如果存在匹配项,则单击事件属于其中一个子项,因此不被视为在组件之外。
因此,在我的组件中,我想将一个单击处理程序附加到窗口。当处理程序启动时,我需要将目标与组件的dom子级进行比较。
click事件包含类似“path”的财产,它似乎保存了事件经过的dom路径。我不知道该比较什么,或者如何最好地遍历它,我想肯定有人已经把它放在了一个聪明的效用函数中。。。不
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])
}
基于Tanner Linsley在2020年夏威夷联合会议上的精彩演讲:
使用OuterClick API
const Client = () => {
const innerRef = useOuterClick(ev => {/*event handler code on outer click*/});
return <div ref={innerRef}> Inside </div>
};
实施
function useOuterClick(callback) {
const callbackRef = useRef(); // initialize mutable ref, which stores callback
const innerRef = useRef(); // 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", handleClick);
return () => document.removeEventListener("click", handleClick);
function handleClick(e) {
if (innerRef.current && callbackRef.current &&
!innerRef.current.contains(e.target)
) callbackRef.current(e);
}
}, []); // no dependencies -> stable click listener
return innerRef; // convenience for client (doesn't need to init ref himself)
}
下面是一个工作示例:
/*自定义挂钩*/函数useOuterClick(回调){const innerRef=useRef();const callbackRef=useRef();//在ref中设置当前回调,然后第二个useEffect使用它useEffect(()=>{//useEffect包装器对于并发模式是安全的callbackRef.current=回调;});使用效果(()=>{document.addEventListener(“单击”,handleClick);return()=>document.removeEventListener(“单击”,handleClick);//从ref中读取最近的回调和innerRefdom节点函数句柄Click(e){如果(内部参考当前&&回调参考当前&&!innerRef.current.contains(e.target)) {callbackRef.current(e);}}}, []); // 无需回调+innerRef-depreturn innerRef;//返回参考;客户端可以省略`useRef`}/*用法*/常量客户端=()=>{const[counter,setCounter]=useState(0);const innerRef=useOuterClick(e=>{//调用处理程序时,计数器状态是最新的alert(`Clicked outside!Increment counter to${counter+1}`);设置计数器(c=>c+1);});返回(<div><p>点击外面</p><div id=“container”ref={innerRef}>内部,计数器:{counter}</div></div>);};ReactDOM.render(<Client/>,document.getElementById(“root”));#容器{边框:1px纯红色;填充:20px;}<script src=“https://cdnjs.cloudflare.com/ajax/libs/react/16.12.0/umd/react.production.min.js“integrity=”sha256-Ef0vObdWpkMAnxp39TYSLVS/vVUokDE8CDFnx7tjY6U=“crossrorigin=”匿名“></script><script src=“https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.12.0/umd/react-dom.production.min.js“integrity=”sha256-p2yuFdE8hNZsQ31Qk+s8N+Me2fL5cc6NKXOC0U9uGw=“crossrorigin=”匿名“></script><script>var{useRef,useEffect,useCallback,useState}=反应</script><div id=“root”></div>
要点
useOuterClick利用可变引用提供瘦客户端API包含组件([]deps)的生命周期的稳定单击侦听器客户端可以设置回调,而无需使用callback将其记忆回调主体可以访问最新的属性和状态-没有过时的闭包值
(iOS的侧注)
iOS通常只将某些元素视为可点击的。要使外部单击有效,请选择一个不同于文档的单击侦听器-不向上包括正文。例如,在React根div上添加一个监听器,并扩展其高度,如height:100vh,以捕捉所有外部点击。来源:quicksmod.org
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>;
}
}
这是我解决问题的方法
我从我的自定义钩子返回一个布尔值,当这个值发生变化时(如果单击在我作为参数传递的ref之外,则为true),这样我就可以用useEffect钩子捕捉到这个变化,我希望你能清楚。
下面是一个活生生的例子:codesandbox上的实时示例
import { useEffect, useRef, useState } from "react";
const useOutsideClick = (ref) => {
const [outsieClick, setOutsideClick] = useState(null);
useEffect(() => {
const handleClickOutside = (e) => {
if (!ref.current.contains(e.target)) {
setOutsideClick(true);
} else {
setOutsideClick(false);
}
setOutsideClick(null);
};
document.addEventListener("mousedown", handleClickOutside);
return () => {
document.removeEventListener("mousedown", handleClickOutside);
};
}, [ref]);
return outsieClick;
};
export const App = () => {
const buttonRef = useRef(null);
const buttonClickedOutside = useOutsideClick(buttonRef);
useEffect(() => {
// if the the click was outside of the button
// do whatever you want
if (buttonClickedOutside) {
alert("hey you clicked outside of the button");
}
}, [buttonClickedOutside]);
return (
<div className="App">
<button ref={buttonRef}>click outside me</button>
</div>
);
}