在React和jQuery中获取鼠标坐标 [英] getting mouse coordinates in React and jQuery
问题描述
我正在尝试使用jQuery获取鼠标在React元素中的相对坐标.
我的代码似乎无法正常运行，并且没有控制台错误.
代码:
index.html
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<link rel="stylesheet" type="text/css" href="stylesheets.css" >
<script src="https://code.jquery.com/jquery-3.1.0.js"></script>
<script src="ja.js" type="text/javascript"></script>
<title>Where's Waldo</title>
</head>
<div id="root"></div>
</body>
</html>
ja.js(jQuery函数)
jQuery(function($) {
var x,y;
$("#waldo1").mousemove(function(event) {
var offset = $(this).offset();
x = event.pageX- offset.left;
y = event.pageY- offset.top;
$("#coords").html("(X: "+x+", Y: "+y+")");
});
});
组件
import React, { Component } from 'react'
import Timer from './timer'
class Level1 extends Component {
render () {
return (
<div>
<div id="gameBoard">
<img id="waldo1" src={require('../images/waldo1(1).jpg')} alt="waldo"/>
</div>
<h2 id="coords"></h2>
<Timer start={Date.now()}/>
</div>
) // return
} // render
} //component
export default Level1
我听说jQuery在反应方面表现不佳.我的语法正确还是完全有更好的方法?
谢谢.
就像其他人提到的那样，问题是当jQuery尝试附加事件侦听器时，react尚未将您的组件呈现到DOM.
您根本不需要jQuery来执行此操作，更好的方法是使用React事件:
class Application extends React.Component {
constructor(props) {
super(props);
this.state = { x: 0, y: 0 };
}
_onMouseMove(e) {
this.setState({ x: e.screenX, y: e.screenY });
}
render() {
const { x, y } = this.state;
return <div onMouseMove={this._onMouseMove.bind(this)}>
<h1>Mouse coordinates: { x } { y }</h1>
</div>;
}
}
示例笔: https://codepen.io/CarlosEME/pen/XWWpVMp
I am trying to get the relative coordinates of the mouse in an element in React using jQuery.
My code doesn't seem to be working and there are no console errors.
code:
index.html
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<link rel="stylesheet" type="text/css" href="stylesheets.css" >
<script src="https://code.jquery.com/jquery-3.1.0.js"></script>
<script src="ja.js" type="text/javascript"></script>
<title>Where's Waldo</title>
</head>
<div id="root"></div>
</body>
</html>
ja.js (jQuery function)
jQuery(function($) {
var x,y;
$("#waldo1").mousemove(function(event) {
var offset = $(this).offset();
x = event.pageX- offset.left;
y = event.pageY- offset.top;
$("#coords").html("(X: "+x+", Y: "+y+")");
});
});
component
import React, { Component } from 'react'
import Timer from './timer'
class Level1 extends Component {
render () {
return (
<div>
<div id="gameBoard">
<img id="waldo1" src={require('../images/waldo1(1).jpg')} alt="waldo"/>
</div>
<h2 id="coords"></h2>
<Timer start={Date.now()}/>
</div>
) // return
} // render
} //component
export default Level1
I hear jQuery doen't play nice with react. Is my syntax correct or is there a better way entirely?
Thank you.
As others have mentioned, the issue is that react has not rendered your component to the DOM when jQuery tries to attach the event listener.
You don't need jQuery to do this at all, a better approach is to use the React events:
class Application extends React.Component {
constructor(props) {
super(props);
this.state = { x: 0, y: 0 };
}
_onMouseMove(e) {
this.setState({ x: e.screenX, y: e.screenY });
}
render() {
const { x, y } = this.state;
return <div onMouseMove={this._onMouseMove.bind(this)}>
<h1>Mouse coordinates: { x } { y }</h1>
</div>;
}
}
Example pen: https://codepen.io/CarlosEME/pen/XWWpVMp
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