鼠标拖动改变DIV等网页元素的大小的实现方法

时间：2021-05-25

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。

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