react中实现可拖动div
把拖动div功能用react封装成class，在页面直接引入该class即可使用。
title为可拖动区域。panel为要实现拖动的容器。
优化了拖动框超出页面范围的情况，也优化了拖动太快时鼠标超出可拖动区域的情况，优化了拖动会卡顿的情况。
页面中添加引入方法：
<Draggable panelId="要拖动容器的id" titleId="容器内标题的id" contentId="容器内除标题外的其他部分id" setPanelPosition={this.setPanelPosition.bind(this)}/>页面中添加拖拽回调函数
//推拽回调函数
setPanelPosition(left,top){
this.setState({pageX: left, pageY: top})
}要拖动的div如下：
<div id="要拖动的id" style={{left:this.state.pageX,top:this.state.pageY}}></div>
封装的class代码：
import React from 'react';
class Draggable extends React.Component {
constructor(props) {
super(props);
this.state = {
};
}
//拖拽
initDrag(){
let {panelId,titleId,contentId} = this.props;
this.paneldom = document.getElementById(panelId);
this.titleDom = document.getElementById(titleId);
this.contentDom = document.getElementById(contentId);
this.backgroundDom = document.body;
this.bindEvent();
}
//region event
componentDidMount() {
this.initDrag();
}
bindEvent(){
this.titleDom.onmousedown = this.onMouseDown.bind(this);
this.titleDom.onmouseup = this.onMouseUp.bind(this);
this.titleDom.onmousemove = this.onMouseMove.bind(this);
this.contentDom.onmouseup = this.onContentMouseUp.bind(this);
this.contentDom.onmousemove = this.onContentMouseMove.bind(this);
this.backgroundDom.onmouseup = this.onBackgroundMouseUp.bind(this);
this.backgroundDom.onmousemove = this.onBackgroundMouseMove.bind(this);
let step = ()=>{
this.activeAnimation = true;
window.requestAnimationFrame(step);
};
window.requestAnimationFrame(step);
}
/**
* 鼠标按下，设置modal状态为可移动，并注册鼠标移动事件
* 计算鼠标按下时，指针所在位置与modal位置以及两者的差值
**/
onMouseDown (e) {
const position = this.getPosition(e)
this.setState({moving: true, diffX: position.diffX, diffY: position.diffY})
}
// 松开鼠标，设置modal状态为不可移动
onMouseUp (e) {
const { moving } = this.state
moving && this.setState({moving: false});
}
// 鼠标移动重新设置modal的位置
onMouseMove (e) {
const {moving, diffX, diffY} = this.state
if (moving) {
if(this.activeAnimation){
// 获取鼠标位置数据
const position = this.getPosition(e)
// 计算modal应该随鼠标移动到的坐标
const x = position.mouseX - diffX
const y = position.mouseY - diffY
// 窗口大小，结构限制，需要做调整，减去侧边栏宽度
const { clientWidth, clientHeight } = document.documentElement
const modal = this.panelDom
if (modal) {
// 计算modal坐标的最大值
const maxHeight = clientHeight - modal.offsetHeight
const maxWidth = clientWidth - modal.offsetWidth
// 判断得出modal的最终位置，不得超出浏览器可见窗口
const left = x > 0 ? (x < maxWidth ? x : maxWidth) : 0
const top = y > 0 ? (y < maxHeight ? y : maxHeight) : 0
if(this.props.setPanelPosition){
this.props.setPanelPosition(left,top);
}
}
this.activeAnimation = false;
}
}
}
onContentMouseMove(e){
let obj = {};
obj.target = this.titleDom;
obj.pageX = e.pageX;
obj.screenY = e.screenY;
this.onMouseMove(obj);
}
onContentMouseUp(){
this.onMouseUp();
}
onBackgroundMouseMove(e){
let obj = {};
obj.target = this.titleDom;
obj.pageX = e.pageX;
obj.screenY = e.screenY;
this.onMouseMove(obj);
}
onBackgroundMouseUp(){
this.onMouseUp();
}
//endregion
//region request
// 获取鼠标点击title时的坐标、title的坐标以及两者的位移
getPosition (e) {
// 标题DOM元素titleDom
const titleDom = e.target
// titleDom的坐标(视窗)
const X = titleDom.getBoundingClientRect().left
// 由于Y轴出现滚动条，需要与鼠标保持一致，存储页面相对位置
const Y = this.panelDom.offsetTop
// 鼠标点击的坐标(页面)
let mouseX = e.pageX
let mouseY = e.screenY
// 鼠标点击位置与modal的位移
const diffX = mouseX - X
const diffY = mouseY - Y
return {X, Y, mouseX, mouseY, diffX, diffY}
}
//endregion
//region render
//endregion
//region clear
//endregion
render() {
return (
<>
</>
);
}
}
export default Draggable;本文内容仅供个人学习、研究或参考使用，不构成任何形式的决策建议、专业指导或法律依据。未经授权，禁止任何单位或个人以商业售卖、虚假宣传、侵权传播等非学习研究目的使用本文内容。如需分享或转载，请保留原文来源信息，不得篡改、删减内容或侵犯相关权益。感谢您的理解与支持！
