<div id="div1"></div> <div id="div2"></div> <div id="div3"></div>
CSS
#div1{ width: 100px; height: 100px; background: red; position: absolute; } #div2{ width: 100px; height: 100px; background: yellow; position: absolute; left: 100px; } #div3{ width: 100px; height: 100px; background: blue; position: absolute; left: 200px; }
JS
/* 组件开发:多组对象,像兄弟之间的关系(代码复用的一种形式) * */ //拖拽 function Drag(){ this.obj=null; this.disX=0; this.disY=0; this.settings={ //默认参数 toDown:function(){}, toUp:function(){} }; } Drag.prototype.init=function(opt){ var This=this; this.obj=document.getElementById(opt.id); extend(this.settings,opt); this.obj.onmousedown=function(ev){ var ev=ev||window.event; This.fnDown(ev); This.settings.toDown(); document.onmousemove=function(ev){ var ev=ev||window.event; This.fnMove(ev); }; document.onmouseup=function(ev){ var ev=ev||window.event; This.fnUp(ev); This.settings.toUp(); }; //清除默认事件 return false; } } Drag.prototype.fnDown=function(ev){ var This=this; this.disX=ev.clientX-this.obj.offsetLeft; this.disY=ev.clientY-this.obj.offsetTop; //设置全局捕获 //所有的onmousemove或者onmouseup都被oImg截获,然后作用在oImg身上 if(this.obj.setCapture){ this.obj.setCapture(); } document.onmousemove=function(ev){ var ev=ev||window.event; This.fnMove(ev); }; document.onmouseup=function(ev){ var ev=ev||window.event; This.fnUp(ev); }; } Drag.prototype.fnMove=function(ev){ var L=ev.clientX-this.disX; var T=ev.clientY-this.disY; this.obj.style.left=L+‘px‘; this.obj.style.top=T+‘px‘; } Drag.prototype.fnUp=function(){ document.onmousemove=null; //释放全局捕获 if(this.obj.releaseCapture){ this.obj.releaseCapture(); } } var dl=new Drag(); dl.init({ //配置参数 id:‘div1‘ }); var d2=new Drag(); d2.init({ //配置参数 id:‘div2‘, toDown:function(){ document.title=‘hello‘; } }); var d3=new Drag(); d3.init({ //配置参数 id:‘div3‘, toDown:function(){ document.title=‘你好‘; }, toUp:function(){ document.title=‘BeyBey‘; } }); function extend(obj1,obj2){ for (var attr in obj2) { obj1[attr]=obj2[attr]; } }