鼠標(biāo)拖動(dòng)改變DIV等網(wǎng)頁元素的大小的實(shí)現(xiàn)方法

更新時(shí)間：2017年07月06日 07:52:38 投稿：jingxian

下面小編就為大家?guī)硪黄髽?biāo)拖動(dòng)改變DIV等網(wǎng)頁元素的大小的實(shí)現(xiàn)方法。小編覺得挺不錯(cuò)的，現(xiàn)在就分享給大家，也給大家做個(gè)參考。一起跟隨小編過來看看吧

1.初次實(shí)現(xiàn)

1.1 html代碼

<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代碼

var eleLeft = $('#myDiv').offset().left;
        var isMouseDown = false;
        var borderLen = 4; //左右邊框
        
        $('#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'); //新鼠標(biāo)位置-div距左-borderLen
            }
          },
          mouseup:function(e){
            isMouseDown = false;
          }
        });

1.3 結(jié)果

只能往左拖動(dòng)使div寬度變小，往右拖動(dòng)沒有用！原因往右拖動(dòng)鼠標(biāo)mousemove事件無法被div捕獲了。拖動(dòng)時(shí)也很難停下來！所以得改進(jìn)。

2.再次改進(jìn)

$('#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;
          }
        });

這次解決了上述問題，可以往右拖，并且隨時(shí)可以停下來了。到這里就完成了嗎？NO!

當(dāng)我引入一個(gè)其他div，并且阻止mouseup事件冒泡情況怎么樣呢？答案是，拖動(dòng)到這個(gè)其它div上放開鼠標(biāo)后無法停止下來！

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

　　　　　　　　　$('#otherDiv').mouseup(function(e){
          //e.preventDefault(); //阻止默認(rèn)行為
          e.stopPropagation(); //阻止事件冒泡(導(dǎo)致body捕獲不到mouseup事件)
        });

3.完美解決

拖動(dòng)停止可能受到其它元素的干擾，怎么解決？想到一些彈出層點(diǎn)擊其它其它地方隱藏的功能，讓我想到了，加一個(gè)遮罩層，讓mouseup事件總是可以響應(yīng)，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;

              //創(chuàng)建遮罩層，防止mouseup事件被其它元素阻止冒泡，導(dǎo)致mouseup事件無法被body捕獲，導(dǎo)致拖動(dòng)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(); //阻止默認(rèn)行為
          e.stopPropagation(); //阻止事件冒泡(導(dǎo)致body捕獲不到mouseup事件)
        });

4.完整代碼和最終效果

<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; //左右邊框

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

              //創(chuàng)建遮罩層，防止mouseup事件被其它元素阻止冒泡，導(dǎo)致mouseup事件無法被body捕獲，導(dǎo)致拖動(dòng)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(); //阻止默認(rèn)行為
          e.stopPropagation(); //阻止事件冒泡(導(dǎo)致body捕獲不到mouseup事件)
        });
      });
    </script>
</html>