百度空间的弹出窗口和拖拽效果，看起来挺不错的。现在很多知名网站都是用的这样的技术。下面把我down的js代码发出来，我分析了一部分，但是还有很多东西不明白怎么回事，没有写注释的部分，还请高手能帮我解释一下。本人属于初学，有不对的地方还请多多指教。
在声明一条吧，此代码仅做学习用，技术版权属于百度。
主要是一个叫做：popup.js的文件，如下：
/**//*********************************************** popup.js**************************************************/
//为数组Array添加一个push方法
//为数组的末尾加入一个对象
if(!Array.prototype.push)
{
Array.prototype.push=function ()
{
var startLength=this.length;
for(var i=0;i<arguments.length;i++)
{
this[startLength+i]=arguments[i];
}
return this.length;
}
};
//对G函数的参数进行处理
function G()
{
//定义一个数组用来保存参数
var elements=new Array();
//循环分析G中参数的内容
for(var i=0;i<arguments.length;i++)
{
var element=arguments[i];
//如果参数的类型为string，则获得以这个参数为ID的对象
if(typeof element=='string')
{
element=document.getElementById(element);
}
//如果参数的长度为1
if(arguments.length==1)
{
return element;
}
//将对象加入到数组的末尾
elements.push(element);
};
return elements;
};
Function.prototype.bind=function (object)
{
var __method=this;
return function ()
{
__method.apply(object,arguments);
};
};
//绑定事件
Function.prototype.bindAsEventListener=function (object)
{
var __method=this;
return function (event){__method.call(object,event||window.event);};
};
Object.extend=function (destination,source)
{
for(property in source)
{
destination[property]=source[property];
};
return destination;
};
if(!window.Event)
{
var Event=new Object();
};
Object.extend(
Event,
{
observers:false,
element:function (event)
{
return event.target||event.srcElement;
},
isLeftClick:function (event)
{
return (((event.which)&&(event.which==1))||((event.button)&&(event.button==1)));
},
pointerX:function (event)
{
return event.pageX||(event.clientX+(document.documentElement.scrollLeft||document.body.scrollLeft));
},
pointerY:function (event)
{
return event.pageY||(event.clientY+(document.documentElement.scrollTop||document.body.scrollTop));
},
stop:function (event)
{
if(event.preventDefault)
{
event.preventDefault();
event.stopPropagation();
}
else
{
event.returnValue=false;
event.cancelBubble=true;
};
},
findElement:function (event,tagName)
{
var element=Event.element(event);
while(element.parentNode&&(!element.tagName||(element.tagName.toUpperCase()!=tagName.toUpperCase())))
element=element.parentNode;
return element;
},
_observeAndCache:function (element,name,observer,useCapture)
{
if(!this.observers)
this.observers=[];
if(element.addEventListener)
{
this.observers.push([element,name,observer,useCapture]);
element.addEventListener(name,observer,useCapture);
}
else if(element.attachEvent)
{
this.observers.push([element,name,observer,useCapture]);
element.attachEvent('on'+name,observer);
};
},
unloadCache:function ()
{
if(!Event.observers)
return;
for(var i=0;i<Event.observers.length;i++)
{
Event.stopObserving.apply(this,Event.observers[i]);
Event.observers[i][0]=null;
};
Event.observers=false;
},
observe:function (element,name,observer,useCapture)
{
var element=G(element);
useCapture=useCapture||false;
if(name=='keypress'&&(navigator.appVersion.match(/Konqueror|Safari|KHTML/)||element.attachEvent))
name='keydown';
this._observeAndCache(element,name,observer,useCapture);
},
stopObserving:function (element,name,observer,useCapture)
{
var element=G(element);
useCapture=useCapture||false;
if(name=='keypress'&&(navigator.appVersion.match(/Konqueror|Safari|KHTML/)||element.detachEvent))
name='keydown';
if(element.removeEventListener)
{
element.removeEventListener(name,observer,useCapture);
}
else if(element.detachEvent)
{
element.detachEvent('on'+name,observer);
};
}
}
);
Event.observe(window,'unload',Event.unloadCache,false);
var Class=function ()
{
var _class=function ()
{
this.initialize.apply(this,arguments);
};
for(i=0;i<arguments.length;i++)
{
superClass=arguments[i];
for(member in superClass.prototype)
{
_class.prototype[member]=superClass.prototype[member];
};
};
_class.child=function ()
{
return new Class(this);
};
_class.extend=function (f)
{
for(property in f)
{
_class.prototype[property]=f[property];
};
};
return _class;
};
//改变百度空间的最顶端和最低端的div的id值
//如果flag为begin，则为弹出状态的id值
//如果flag为end，则为非弹出状态的id值，即原本的id值
function space(flag)
{
if(flag=="begin")
{
var ele=document.getElementById("ft");
if(typeof(ele)!="#ff0000"&&ele!=null)
ele.id="ft_popup";
ele=document.getElementById("usrbar");
if(typeof(ele)!="undefined"&&ele!=null)
ele.id="usrbar_popup";
}
else if(flag=="end")
{
var ele=document.getElementById("ft_popup");
if(typeof(ele)!="undefined"&&ele!=null)
ele.id="ft";
ele=document.getElementById("usrbar_popup");
if(typeof(ele)!="undefined"&&ele!=null)
ele.id="usrbar";
};
};
//**************************************************Popup类弹出窗口***************************************************************
var Popup=new Class();
Popup.prototype={
//弹出窗口中框架的name名称
iframeIdName:'ifr_popup',
initialize:function (config)
{
//---------------弹出对话框的配置信息------------------
//contentType:设置内容区域为什么类型：1为另外一个html文件 | 2为自定义html字符串 | 3为confirm对话框 | 4为alert警告对话框
//isHaveTitle:是否显示标题栏
//scrollType：设置或获取对话框中的框架是否可被滚动
//isBackgroundCanClick：弹出对话框后，是否允许蒙布后的所有元素被点击。也就是如果为false的话，就会有全屏蒙布，如果为true的话，就会去掉全屏蒙布
//isSupportDraging：是否支持拖拽
//isShowShadow：是否现实阴影
//isReloadOnClose：是否刷新页面，并关闭对话框
//width：宽度
//height：高度
this.config=Object.extend({contentType:1,isHaveTitle:true,scrollType:'yes',isBackgroundCanClick:false,isSupportDraging:true,isShowShadow:true,isReloadOnClose:true,width:400,height:300},config||{});
//----------------对话框的参数值信息------------------------
//shadowWidth ：阴影的宽度
//contentUrl ：html链接页面
//contentHtml ：html内容
//callBack ：回调的函数名
//parameter ：回调的函数名中传的参数
//confirmCon ：对话框内容
//alertCon ：警告框内容
//someHiddenTag：页面中需要隐藏的元素列表，以逗号分割
//someHiddenEle：需要隐藏的元素的ID列表(和someToHidden的区别是：someHiddenEle是通过getElementById，而someToHidden是通过getElementByTagName，里面放的是对象)
//overlay ：
//coverOpacity ：蒙布的透明值
this.info={shadowWidth:4,title:"",contentUrl:"",contentHtml:"",callBack:null,parameter:null,confirmCon:"",alertCon:"",someHiddenTag:"select,object,embed",someHiddenEle:"",overlay:0,coverOpacity:40};
//设置颜色cColor:蒙布的背景, bColor:内容区域的背景, tColor:标题栏和边框的颜色,wColor:字体的背景色
this.color={cColor:"#EEEEEE",bColor:"#FFFFFF",tColor:"#709CD2",wColor:"#FFFFFF"};
this.dropClass=null;
//用来放置隐藏了的对象列表，在hiddenTag方法中第一次调用
this.someToHidden=[];
//如果没有标题栏则不支持拖拽
if(!this.config.isHaveTitle)
{
this.config.isSupportDraging=false;
}
//初始化
this.iniBuild();
},
//设置配置信息和参数内容
setContent:function (arrt,val)
{
if(val!='')
{
switch(arrt)
{
case 'width':this.config.width=val;
break;
case 'height':this.config.height=val;
break;
case 'title':this.info.title=val;
break;
case 'contentUrl':this.info.contentUrl=val;
break;
case 'contentHtml':this.info.contentHtml=val;
break;
case 'callBack':this.info.callBack=val;
break;
case 'parameter':this.info.parameter=val;
break;
case 'confirmCon':this.info.confirmCon=val;
break;
case 'alertCon':this.info.alertCon=val;
break;
case 'someHiddenTag':this.info.someHiddenTag=val;
break;
case 'someHiddenEle':this.info.someHiddenEle=val;
break;
case 'overlay':this.info.overlay=val;
};
};
},
iniBuild:function ()
{
G('dialogCase')?G('dialogCase').parentNode.removeChild(G('dialogCase')):function (){};
var oDiv=document.createElement('span');
oDiv.id='dialogCase';
document.body.appendChild(oDiv);
},
build:function ()
{
//设置全屏蒙布的z-index
var baseZIndex=10001+this.info.overlay*10;
//设置蒙布上的弹出窗口的z-index(比蒙布的z-index高2个值)
var showZIndex=baseZIndex+2;
//定义框架名称
this.iframeIdName='ifr_popup'+this.info.overlay;
//设置图片的主路径
var path="http://img.baidu.com/hi/img/";
//关闭按钮
var close='<input type="image" id="dialogBoxClose" src="'+path+'dialogclose.gif" border="0" width="16" height="16" align="absmiddle" title="关闭"/>';
//使用滤镜设置对象的透明度
var cB='filter: alpha(opacity='+this.info.coverOpacity+');opacity:'+this.info.coverOpacity/100+';';
//设置全屏的蒙布
var cover='<div id="dialogBoxBG" style="position:absolute;top:0px;left:0px;width:100%;height:100%;z-index:'+baseZIndex+';'+cB+'background-color:'+this.color.cColor+';display:none;"></div>';
//设置弹出的主窗口设置
var mainBox='<div id="dialogBox" style="border:1px solid '+this.color.tColor+';display:none;z-index:'+showZIndex+';position:relative;width:'+this.config.width+'px;"><table width="100%" border="0" cellpadding="0" cellspacing="0" bgcolor="'+this.color.bColor+'">';
//设置窗口标题栏
if(this.config.isHaveTitle)
{
mainBox+='<tr height="24" bgcolor="'+this.color.tColor+'"><td><table style="-moz-user-select:none;height:24px;" width="100%" border="0" cellpadding="0" cellspacing="0" ><tr>'+'<td width="6" height="24"></td><td id="dialogBoxTitle" style="color:'+this.color.wColor+';font-size:14px;font-weight:bold;">'+this.info.title+' </td>'+'<td id="dialogClose" width="20" align="right" valign="middle">'+close+'</td><td width="6"></td></tr></table></td></tr>';
}
else
{
mainBox+='<tr height="10"><td align="right">'+close+'</td></tr>';
};
//设置窗口主内容区域
mainBox+='<tr style="height:'+this.config.height+'px" valign="top"><td id="dialogBody" style="position:relative;"></td></tr></table></div>'+'<div id="dialogBoxShadow" style="display:none;z-index:'+baseZIndex+';"></div>';
//如果有蒙布
if(!this.config.isBackgroundCanClick)
{
G('dialogCase').innerHTML=cover+mainBox;
G('dialogBoxBG').style.height=document.body.scrollHeight;
}
else
{
G('dialogCase').innerHTML=mainBox;
}
Event.observe(G('dialogBoxClose'),"click",this.reset.bindAsEventListener(this),false);
//如果支持拖动,则设置拖动处理
if(this.config.isSupportDraging)
{
dropClass=new Dragdrop(this.config.width,this.config.height,this.info.shadowWidth,this.config.isSupportDraging,this.config.contentType);
G("dialogBoxTitle").style.cursor="move";
};
this.lastBuild();
},
lastBuild:function ()
{
//设置confim对话框的具体内容
var confirm='<div style="width:100%;height:100%;text-align:center;"><div style="margin:20px 20px 0 20px;font-size:14px;line-height:16px;color:#000000;">'+this.info.confirmCon+'</div><div style="margin:20px;"><input id="dialogOk" type="button" value=" 确定 "/> <input id="dialogCancel" type="button" value=" 取消 "/></div></div>';
//设置alert对话框的具体内容
var alert='<div style="width:100%;height:100%;text-align:center;"><div style="margin:20px 20px 0 20px;font-size:14px;line-height:16px;color:#000000;">'+this.info.alertCon+'</div><div style="margin:20px;"><input id="dialogYES" type="button" value=" 确定 "/></div></div>';
var baseZIndex=10001+this.info.overlay*10;
var coverIfZIndex=baseZIndex+4;
//判断内容类型决定窗口的主内容区域应该显示什么
if(this.config.contentType==1)
{
var openIframe="<iframe width='100%' style='height:"+this.config.height+"px' name='"+this.iframeIdName+"' id='"+this.iframeIdName+"' src='"+this.info.contentUrl+"' frameborder='0' scrolling='"+this.config.scrollType+"'></iframe>";
var coverIframe="<div id='iframeBG' style='position:absolute;top:0px;left:0px;width:1px;height:1px;z-index:"+coverIfZIndex+";filter: alpha(opacity=00);opacity:0.00;background-color:#ffffff;'><div>";
G("dialogBody").innerHTML=openIframe+coverIframe;
}
else if(this.config.contentType==2)
{
G("dialogBody").innerHTML=this.info.contentHtml;
}
else if(this.config.contentType==3)
{
G("dialogBody").innerHTML=confirm;Event.observe(G('dialogOk'),"click",this.forCallback.bindAsEventListener(this),false);
Event.observe(G('dialogCancel'),"click",this.close.bindAsEventListener(this),false);
}
else if(this.config.contentType==4)
{
G("dialogBody").innerHTML=alert;
Event.observe(G('dialogYES'),"click",this.close.bindAsEventListener(this),false);
};
},
//重新加载弹出窗口的高度和内容
reBuild:function ()
{
G('dialogBody').height=G('dialogBody').clientHeight;
this.lastBuild();
},
show:function ()
{
//隐藏一些在info中制定的元素
this.hiddenSome();
//弹出窗口居中
this.middle();
//设置阴影
if(this.config.isShowShadow)
this.shadow();
},
//设置回调函数
forCallback:function ()
{
return this.info.callBack(this.info.parameter);
},
//为弹出窗口设置阴影
shadow:function ()
{
var oShadow=G('dialogBoxShadow');
var oDialog=G('dialogBox');oShadow['style']['position']="absolute";
oShadow['style']['background']="#000";
oShadow['style']['display']="";
oShadow['style']['opacity']="0.2";
oShadow['style']['filter']="alpha(opacity=20)";
oShadow['style']['top']=oDialog.offsetTop+this.info.shadowWidth;
oShadow['style']['left']=oDialog.offsetLeft+this.info.shadowWidth;
oShadow['style']['width']=oDialog.offsetWidth;oShadow['style']['height']=oDialog.offsetHeight;
},
//让弹出窗口居中显示
middle:function ()
{
if(!this.config.isBackgroundCanClick)
G('dialogBoxBG').style.display='';
var oDialog=G('dialogBox');
oDialog['style']['position']="absolute";
oDialog['style']['display']='';
var sClientWidth=document.body.clientWidth;
var sClientHeight=document.body.clientHeight;
var sScrollTop=document.body.scrollTop;
//alert("document.body.clientWidth = " + sClientWidth + "\ndocument.body.clientHeight" +sClientHeight);
var sleft=(document.body.clientWidth/2)-(oDialog.offsetWidth/2);
var iTop=-80+(sClientHeight/2+sScrollTop)-(oDialog.offsetHeight/2);
var sTop=iTop>0?iTop:(sClientHeight/2+sScrollTop)-(oDialog.offsetHeight/2);
//alert("var iTop=-80+(sClientHeight/2+sScrollTop)-(oDialog.offsetHeight/2);\n" + "sClientHeight is " + sClientHeight + "\nsScrollTop is " + sScrollTop);
//alert("iTop is " + iTop);
if(sTop<1)
sTop="20";
if(sleft<1)
sleft="20";
oDialog['style']['left']=sleft;
oDialog['style']['top']=sTop;
//alert("sleft is " + sleft);
//alert("sTop is " + sTop);
},
//刷新页面，并关闭当前弹出窗口
reset:function ()
{
if(this.config.isReloadOnClose)
{
top.location.reload();
};
this.close();
},
//关闭当前弹出窗口
close:function ()
{
G('dialogBox').style.display='none';
if(!this.config.isBackgroundCanClick)
G('dialogBoxBG').style.display='none';
if(this.config.isShowShadow)
G('dialogBoxShadow').style.display='none';
G('dialogBody').innerHTML='';
this.showSome();
},
//隐藏someHiddenTag和someHiddenEle中的所有元素
hiddenSome:function ()
{
//隐藏someHiddenTag中的所有元素
var tag=this.info.someHiddenTag.split(",");
if(tag.length==1&&tag[0]=="")
{
tag.length=0;
}
for(var i=0;i<tag.length;i++)
{
this.hiddenTag(tag[i]);
};
//隐藏someHiddenEle中的所有逗号分割的ID的元素
var ids=this.info.someHiddenEle.split(",");
if(ids.length==1&&ids[0]=="")
ids.length=0;
for(var i=0;i<ids.length;i++)
{
this.hiddenEle(ids[i]);
};
//改变顶部和底部的div的id值为弹出状态的id值,祥见space的实现
space("begin");
},
//隐藏一组元素
hiddenTag:function (tagName)
{
var ele=document.getElementsByTagName(tagName);
if(ele!=null)
{
for(var i=0;i<ele.length;i++)
{
if(ele[i].style.display!="none"&&ele[i].style.visibility!='hidden')
{
ele[i].style.visibility='hidden';
this.someToHidden.push(ele[i]);
};
};
};
},
//隐藏单个元素
hiddenEle:function (id)
{
var ele=document.getElementById(id);
if(typeof(ele)!="undefined"&&ele!=null)
{
ele.style.visibility='hidden';
this.someToHidden.push(ele);
}
},
//将someToHidden中保存的隐藏元素全部显示
//并恢复顶部和底部的div为原来的id值
showSome:function ()
{
for(var i=0;i<this.someToHidden.length;i++)
{
this.someToHidden[i].style.visibility='visible';
};
space("end");
}
};
//********************************************************Dragdrop类(拖拽动作)************************************************************
var Dragdrop=new Class();
Dragdrop.prototype={
initialize:function (width,height,shadowWidth,showShadow,contentType)
{
this.dragData=null;
this.dragDataIn=null;
this.backData=null;
this.width=width;
this.height=height;
this.shadowWidth=shadowWidth;
this.showShadow=showShadow;
this.contentType=contentType;
this.IsDraging=false;
this.oObj=G('dialogBox');
Event.observe(G('dialogBoxTitle'),"mousedown",this.moveStart.bindAsEventListener(this),false);
},
moveStart:function (event)
{
this.IsDraging=true;
if(this.contentType==1)
{
G("iframeBG").style.display="";
G("iframeBG").style.width=this.width;
G("iframeBG").style.height=this.height;
};
Event.observe(document,"mousemove",this.mousemove.bindAsEventListener(this),false);
Event.observe(document,"mouseup",this.mouseup.bindAsEventListener(this),false);
Event.observe(document,"selectstart",this.returnFalse,false);
this.dragData={x:Event.pointerX(event),y:Event.pointerY(event)};
this.backData={x:parseInt(this.oObj.style.left),y:parseInt(this.oObj.style.top)};
},
mousemove:function (event)
{
if(!this.IsDraging)
return ;
var iLeft=Event.pointerX(event)-this.dragData["x"]+parseInt(this.oObj.style.left);
var iTop=Event.pointerY(event)-this.dragData["y"]+parseInt(this.oObj.style.top);
if(this.dragData["y"]<parseInt(this.oObj.style.top))
iTop=iTop-12;
else if(this.dragData["y"]>parseInt(this.oObj.style.top)+25)
iTop=iTop+12;
this.oObj.style.left=iLeft;
this.oObj.style.top=iTop;
if(this.showShadow)
{
G('dialogBoxShadow').style.left=iLeft+this.shadowWidth;
G('dialogBoxShadow').style.top=iTop+this.shadowWidth;
};
this.dragData={x:Event.pointerX(event),y:Event.pointerY(event)};
document.body.style.cursor="move";
},
mouseup:function (event)
{
if(!this.IsDraging)
return ;
if(this.contentType==1)
G("iframeBG").style.display="none";
document.onmousemove=null;
document.onmouseup=null;
var mousX=Event.pointerX(event)-(document.documentElement.scrollLeft||document.body.scrollLeft);
var mousY=Event.pointerY(event)-(document.documentElement.scrollTop||document.body.scrollTop);
if(mousX<1||mousY<1||mousX>document.body.clientWidth||mousY>document.body.clientHeight)
{
this.oObj.style.left=this.backData["x"];
this.oObj.style.top=this.backData["y"];
if(this.showShadow)
{
G('dialogBoxShadow').style.left=this.backData.x+this.shadowWidth;
G('dialogBoxShadow').style.top=this.backData.y+this.shadowWidth;
};
};
this.IsDraging=false;
document.body.style.cursor="";
Event.stopObserving(document,"selectstart",this.returnFalse,false);
},
returnFalse:function ()
{
return false;
}
};
将上面对popup.js文件做个引用，下面是对这个js文件进行测试的html页面的代码。你可以回去很方便的测试。
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="PopUpTest.aspx.cs" Inherits="PopUpTest" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>无标题页</title>
<script type="text/javascript" src="Scripts/popup.js"></script>
<script type="text/javascript">
function ShowIframe()
{
var pop=new Popup({ contentType:1,isReloadOnClose:false,width:400,height:500});
pop.setContent("contentUrl","Default.aspx");
pop.setContent("title","iframe框架示例");
pop.build();
pop.show();
}
function ShowHtmlString()
{
var strHtml = "<table border=1 style='width:90%; text-align:center;'><tr style='height:40px'><td>ds</td><td>dads</td></tr><tr style='height:40px'><td>dadas</td><td>dasd</td></tr><tr style='height:40px'><td>dadasd</td><td>dsadads</td></tr></table>";
var pop=new Popup({ contentType:2,isReloadOnClose:false,width:340,height:300});
pop.setContent("contentHtml",strHtml);
pop.setContent("title","html字符串示例");
pop.build();
pop.show();
}
function ShowConfirm()
{
var pop=new Popup({ contentType:3,isReloadOnClose:false,width:340,height:80});
pop.setContent("title","confirm对话框示例");
pop.setContent("confirmCon","confirm对话框的内容");
pop.setContent("callBack",ShowCallBack);
pop.setContent("parameter",{id:"divCall",str:"点击确定后显示的字符串",obj:pop});
pop.build();
pop.show();
}
function ShowAlert()
{
var pop=new Popup({ contentType:4,isReloadOnClose:false,width:340,height:80});
pop.setContent("title","alert警告框示例");
pop.setContent("alertCon","alert对话框的内容");
pop.build();
pop.show();
}
function ShowCallBack(para)
{
var o_pop = para["obj"]
var obj = document.getElementById(para["id"]);
o_pop.close();
obj.innerText = para["str"];
}
</script>
</head>
<body style="text-align:center;">
<form id="form1" runat="server">
<div>
<a href="javascript:ShowIframe()">iframe框架示例</a>
<br />
<a href="javascript:ShowHtmlString()">html字符串示例</a>
<br />
<a href="javascript:ShowConfirm()">confirm对话框示例</a>
<br />
<a href="javascript:ShowAlert()">alert警告框示例</a>
</div>
<div id="divCall" style="width:300px; height:200px; background-color:#cccccc; color:Red; float:right;">
</div>
</form>
</body>
</html>
代码一堆一堆的啊！那个拖拽的不是很清楚怎么回事？上面的那个class函数也不清楚到底是怎么弄的。凡是没有写注释的地方，基本上就不是很明白。我找时间再分析分析吧！找时间把其它的注释也给写上。如果大家明白的，还请多多指教，越详细越好。