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鼠标拖动改变DIV等网页元素的大小的最佳实践

时间:2017-07-05 23:03:06      阅读:340      评论:0      收藏:0      [点我收藏+]

标签:没有   sem   tde   情况   鼠标   down   stop   边框   引入   

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>

 技术分享

鼠标拖动改变DIV等网页元素的大小的最佳实践

标签:没有   sem   tde   情况   鼠标   down   stop   边框   引入   

原文地址:http://www.cnblogs.com/hdwang/p/7123784.html

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