JavaScript

超轻量级php框架startmvc

鼠标拖动改变DIV等网页元素的大小的实现方法

更新时间:2020-05-23 01:00:01 作者:startmvc
1.初次实现1.1html代码<htmlxmlns="http://www.w3.org/1999/xhtml"xml:lang="en"lang="en"><head><metahtt

1.初次实现

1.1 html代码


<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>div change width by drag</title>
 <script src="../jQuery/jquery-1.8.3.min.js" type="text/javascript"></script>
 </head>

 <body>
 <h1>div change width by drag</h1>
 <div id="pos" style="color:red"></div>
 
 <div id="myDiv" style="border:2px solid red;width:300px;height:50px;margin-left: 100px;margin-top: 20px"></div>
 </body>
</html>

1.2 js代码


var eleLeft = $('#myDiv').offset().left;
 var isMouseDown = false;
 var borderLen = 4; //左右边框
 
 $('#myDiv').bind({
 mousedown:function(e){
 var ele = $(this);
 var rightPos = eleLeft + ele.width() + borderLen;
 if(rightPos-5 <= e.pageX && e.pageX <= rightPos){
 isMouseDown = true;

 }
 },
 
 mousemove:function(e){
 var ele = $(this);
 var rightPos = eleLeft + ele.width() + borderLen;
 $('#pos').text("x:"+e.pageX + " eleLeft:"+eleLeft+" rightPos:"+rightPos);

 if(rightPos-5 <= e.pageX && e.pageX <= rightPos){
 ele.css('cursor','e-resize');
 }else{
 if(!isMouseDown){
 ele.css('cursor','auto');
 }
 }
 if(isMouseDown){
 ele.width((e.pageX-eleLeft-borderLen)+'px'); //新鼠标位置-div距左-borderLen
 }
 },
 mouseup:function(e){
 isMouseDown = false;
 }
 });

1.3 结果

只能往左拖动使div宽度变小,往右拖动没有用!原因往右拖动鼠标mousemove事件无法被div捕获了。拖动时也很难停下来!所以得改进。

2.再次改进


$('#myDiv').bind({
 mousedown:function(e){
 var ele = $(this);
 var rightPos = eleLeft + ele.width() + borderLen;
 if(rightPos-5 <= e.pageX && e.pageX <= rightPos){
 isMouseDown = true;
 }
 }
 });

 $('body').bind({
 mousemove:function(e){
 var ele = $('#myDiv');
 var rightPos = eleLeft + ele.width() + borderLen;
 $('#pos').text("x:"+e.pageX + " eleLeft:"+eleLeft+" rightPos:"+rightPos);

 if(rightPos-5 <= e.pageX && e.pageX <= rightPos){
 ele.css('cursor','e-resize');
 }else{
 if(!isMouseDown){
 ele.css('cursor','auto');
 }
 }
 if(isMouseDown){
 ele.width((e.pageX-eleLeft-borderLen)+'px'); 
 }
 },
 mouseup:function(e){
 isMouseDown = false;
 }
 });

这次解决了上述问题,可以往右拖,并且随时可以停下来了。到这里就完成了吗?NO!

当我引入一个其他div,并且阻止mouseup事件冒泡情况怎么样呢?答案是,拖动到这个其它div上放开鼠标后无法停止下来!


<div id="otherDiv" style="border: 2px solid blue;width: 200px;height: 200px;margin-left: 400px"></div>
 

         $('#otherDiv').mouseup(function(e){
 //e.preventDefault(); //阻止默认行为
 e.stopPropagation(); //阻止事件冒泡(导致body捕获不到mouseup事件)
 });
 

3.完美解决

拖动停止可能受到其它元素的干扰,怎么解决?想到一些弹出层点击其它其它地方隐藏的功能,让我想到了,加一个遮罩层,让mouseup事件总是可以响应,不就搞定了嘛!


$('#myDiv').bind({
 mousedown:function(e){
 var ele = $(this);
 var rightPos = eleLeft + ele.width() + borderLen;
 if(rightPos-5 <= e.pageX && e.pageX <= rightPos){
 isMouseDown = true;

 //创建遮罩层,防止mouseup事件被其它元素阻止冒泡,导致mouseup事件无法被body捕获,导致拖动不能停止
 var bodyWidth = $('body').width();
 var bodyHeight = $('body').height();
 $('body').append('<div id="mask" style="opacity:0.2;top:0px;left:0px;background-color:green;position:absolute;z-index:9999;width:'+bodyWidth+'px;height:'+bodyHeight+'px;"></div>');
 }
 }
 });

 $('body').bind({
 mousemove:function(e){
 var ele = $('#myDiv');
 var rightPos = eleLeft + ele.width() + borderLen;
 $('#pos').text("x:"+e.pageX + " eleLeft:"+eleLeft+" rightPos:"+rightPos);

 if(rightPos-5 <= e.pageX && e.pageX <= rightPos){
 ele.css('cursor','e-resize');
 }else{
 if(!isMouseDown){
 ele.css('cursor','auto');
 }
 }
 if(isMouseDown){
 ele.width((e.pageX-eleLeft-borderLen)+'px'); 
 }
 },
 mouseup:function(e){
 isMouseDown = false;
 $('#mask').remove();
 }
 });

 $('#otherDiv').mouseup(function(e){
 //e.preventDefault(); //阻止默认行为
 e.stopPropagation(); //阻止事件冒泡(导致body捕获不到mouseup事件)
 });

4.完整代码和最终效果


<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

 <title>div change width by drag</title>

 <script src="../jQuery/jquery-1.8.3.min.js" type="text/javascript"></script>
 
 
 </head>

 <body>
 <h1>div change width by drag</h1>
 
 <div id="pos" style="color:red"></div>
 
 
 <div id="myDiv" style="border:2px solid red;width:300px;height:50px;margin-left: 100px;margin-top: 20px"></div>

 <div id="otherDiv" style="border: 2px solid blue;width: 200px;height: 200px;margin-left: 400px"></div>
 </body>
 

 <script type="text/javascript">
 $(document).ready(function(){
 var eleLeft = $('#myDiv').offset().left;
 var isMouseDown = false;
 var borderLen = 4; //左右边框

 $('#myDiv').bind({
 mousedown:function(e){
 var ele = $(this);
 var rightPos = eleLeft + ele.width() + borderLen;
 if(rightPos-5 <= e.pageX && e.pageX <= rightPos){
 isMouseDown = true;

 //创建遮罩层,防止mouseup事件被其它元素阻止冒泡,导致mouseup事件无法被body捕获,导致拖动不能停止
 var bodyWidth = $('body').width();
 var bodyHeight = $('body').height();
 $('body').append('<div id="mask" style="opacity:0.2;top:0px;left:0px;background-color:green;position:absolute;z-index:9999;width:'+bodyWidth+'px;height:'+bodyHeight+'px;"></div>');
 }
 }
 });

 $('body').bind({
 mousemove:function(e){
 var ele = $('#myDiv');
 var rightPos = eleLeft + ele.width() + borderLen;
 $('#pos').text("x:"+e.pageX + " eleLeft:"+eleLeft+" rightPos:"+rightPos);

 if(rightPos-5 <= e.pageX && e.pageX <= rightPos){
 ele.css('cursor','e-resize');
 }else{
 if(!isMouseDown){
 ele.css('cursor','auto');
 }
 }
 if(isMouseDown){
 ele.width((e.pageX-eleLeft-borderLen)+'px'); 
 }
 },
 mouseup:function(e){
 isMouseDown = false;
 $('#mask').remove();
 }
 });

 $('#otherDiv').mouseup(function(e){
 //e.preventDefault(); //阻止默认行为
 e.stopPropagation(); //阻止事件冒泡(导致body捕获不到mouseup事件)
 });
 });
 </script>
</html>

以上这篇鼠标拖动改变DIV等网页元素的大小的实现方法就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持脚本之家。

鼠标拖动元素