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JavaScript 拖放效果_html/css_WEB-ITnose

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Jun 24, 2016 am 11:53 AM

拖放效果，也叫拖拽、拖动。一个简单的拖放效果

拖动div

【程序说明】

首先初始化函数，对拖放对象添加mousedown监听事件

 initialize:function(drag){        this.Drag = $$(drag);//拖放对象        this._x = this._y = 0;//记录鼠标相对于拖放对象的位置        this._fM = BindAsEventListener(this, this.Move); //绑定拖动时执行的函数        this._fS = Bind(this, this.Stop); //绑定拖动结束执行的函数        this.Drag.style.position = "absolute";        EventUtil.addEventHandler(this.Drag, "mousedown", BindAsEventListener(this, this.Start));           //监听拖动对象mousedown事件 }

之后在Start方法添加mousemove和mouseup事件，分别监听拖放对象的位置和取消监听事件

             Start:function(oEvent){                 //记录mousedown触发时鼠标相对于拖放对象的位置                 this._x = oEvent.clientX - this.Drag.offsetLeft;                 this._y = oEvent.clientY - this.Drag.offsetTop;                 //监听mousemove 和 mouseup事件                 EventUtil.addEventHandler(document, "mousemove", this._fM);                 EventUtil.addEventHandler(document, "mouseup", this._fS);             }

完整拖放程序：

         /**          *拖放程序          */         var simpleDrag = Class.create();         simpleDrag.prototype = {             //初始化对象             initialize:function(drag){                 this.Drag = $$(drag);//拖放对象                 this._x = this._y = 0;//记录鼠标相对于拖放对象的位置                 this._fM = BindAsEventListener(this, this.Move); //绑定拖动时执行的函数                this._fS = Bind(this, this.Stop); //绑定拖动结束执行的函数                this.Drag.style.position = "absolute";                EventUtil.addEventHandler(this.Drag, "mousedown", BindAsEventListener(this, this.Start));                 //监听拖动对象mousedown事件             },             //准备拖动                 Start:function(oEvent){                 //记录mousedown触发时鼠标相对于拖放对象的位置                 this._x = oEvent.clientX - this.Drag.offsetLeft;                this._y = oEvent.clientY - this.Drag.offsetTop;                //监听mousemove 和 mouseup事件                EventUtil.addEventHandler(document, "mousemove", this._fM);                EventUtil.addEventHandler(document, "mouseup", this._fS);             },                 //拖动             Move:function(oEvent){                 this.Drag.style.left = oEvent.clientX - this._x + "px";                this.Drag.style.top = oEvent.clientY - this._y + "px";             },             //停止拖动             Stop:function(){                EventUtil.removeEventHandler(document, "mousemove", this._fM);                EventUtil.removeEventHandler(document, "mouseup", this._fS);             },         };        //初始化拖动         new simpleDrag('drag');

完整DEMO：

<!DOCTYPE html><html lang="en"><head>    <meta charset="UTF-8">    <title>JavaScript拖放效果</title>    <style type="text/css">    *{margin:0;padding:0;}    .drag-wrap{height: 300px;margin:10px;border:5px solid #FF8000;background:#8080C0;position: relative;}    .draggable{width: 100px;height: 100px;position: absolute;top: 100px;left:100px;background:#eee;border:1px solid #aceaac;cursor: move;}    </style></head><body>    <div class="drag-wrap">         <div class="draggable" id="drag">拖动div</div>    </div>    <div class="drag-status" id="drag-status" style="height:30px;padding:0 10px;"></div>    <script type="text/javascript">        /**          *工具函数          */         var isIE = (document.all) ? true : false ;         var $$ = function(id){             return "string" == typeof id ? document.getElementById(id) : id;          };         var Class = {            create: function() {                return function() { this.initialize.apply(this, arguments); }            }        };        var Extend = function(destination,source){            for(var property in source){                destination[property] = source[property];            }        };        var BindAsEventListener = function(object,func){            return function(event){                return func.call(object,event || window.event);            }        };        var Bind = function(object,func){            return function(){                return func.apply(object,arguments);            }        };         /**          *跨浏览器事件对象          */        var EventUtil = {            //事件注册处理程序            addEventHandler:function(oTarget,sEventType,fnHandler){                 if(oTarget.addEventListener){                     oTarget.addEventListener(sEventType,fnHandler,false);                 }else if(oTarget.attachEvent){                     oTarget.attachEvent("on"+sEventType,fnHandler);                 }else{                     oTarget["on"+sEventType] = fnHandler;                 }             },             //事件移除处理程序             removeEventHandler:function(oTarget,sEventType,fnHandler){                 if(oTarget.removeEventListener){                     oTarget.removeEventListener(sEventType,fnHandler,false);                 }else if(oTarget.detachEvent){                     oTarget.detachEvent("on"+sEventType,fnHandler);                 }else{                     oTarget["on"+sEventType] = null;                 }             },             getEvent:function(event){                 return event ? event : window.event ;             },             getTarget:function(event){                 return event.target || event.srcElement;             }        };            /**          *拖放程序         */         var simpleDrag = Class.create();         simpleDrag.prototype = {             //初始化对象             initialize:function(drag){                 this.Drag = $$(drag);//拖放对象                 this._x = this._y = 0;//记录鼠标相对于拖放对象的位置                 this._fM = BindAsEventListener(this, this.Move); //绑定拖动时执行的函数                this._fS = Bind(this, this.Stop); //绑定拖动结束执行的函数                this.Drag.style.position = "absolute";                EventUtil.addEventHandler(this.Drag, "mousedown", BindAsEventListener(this, this.Start));                 //监听拖动对象mousedown事件             },             //准备拖动                 Start:function(oEvent){                 //记录mousedown触发时鼠标相对于拖放对象的位置                 this._x = oEvent.clientX - this.Drag.offsetLeft;                this._y = oEvent.clientY - this.Drag.offsetTop;                //监听mousemove 和 mouseup事件                EventUtil.addEventHandler(document, "mousemove", this._fM);                EventUtil.addEventHandler(document, "mouseup", this._fS);             },                 //拖动             Move:function(oEvent){                 this.Drag.style.left = oEvent.clientX - this._x + "px";                this.Drag.style.top = oEvent.clientY - this._y + "px";             },             //停止拖动             Stop:function(){                EventUtil.removeEventHandler(document, "mousemove", this._fM);                EventUtil.removeEventHandler(document, "mouseup", this._fS);             },         };        //初始化拖动         new simpleDrag('drag');    </script></body></html>

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