常用js特效之左上角菜单

最新推荐文章于 2021-06-10 01:41:12 发布
原创最新推荐文章于 2021-06-10 01:41:12 发布 · 置顶 · 881 阅读
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#javascript #特效 #左上角菜单
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代码

<!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" xml:lang="en">
<head>
    <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
    <title>Document</title>
</head>
<body>
     <style type="text/css">
#divMenu0 {position:absolute; top:0px; left:30px; visibility:hidden; font-family:arial,helvetica,sans-serif; font-size:18px; font-weight:bold;}
#divMenu1 {position:absolute; top:0px; left:150px; visibility:hidden; font-family:arial,helvetica,sans-serif; font-size:18px; font-weight:bold;}
#divMenu2 {position:absolute; top:0px; left:250px; visibility:hidden; font-family:arial,helvetica,sans-serif; font-size:18px; font-weight:bold;} 
</style>
<script language="JavaScript" type="text/javascript">
function lib_bwcheck(){ //Browsercheck (needed)
    this.ver=navigator.appVersion
    this.agent=navigator.userAgent
    this.dom=document.getElementById?1:0
    this.opera5=this.agent.indexOf("Opera 5")>-1
    this.ie5=(this.ver.indexOf("MSIE 5")>-1 && this.dom && !this.opera5)?1:0; 
    this.ie6=(this.ver.indexOf("MSIE 6")>-1 && this.dom && !this.opera5)?1:0;
    this.ie4=(document.all && !this.dom && !this.opera5)?1:0;
    this.ie=this.ie4||this.ie5||this.ie6
    this.mac=this.agent.indexOf("Mac")>-1
    this.ns6=(this.dom && parseInt(this.ver) >= 5) ?1:0; 
    this.ns4=(document.layers && !this.dom)?1:0;
    this.bw=(this.ie6 || this.ie5 || this.ie4 || this.ns4 || this.ns6 || this.opera5)
    return this
}
var bw=new lib_bwcheck()
//How many pixels should it move every step? 
var tMove=10;

//At what speed (in milliseconds, lower value is more speed)
var tSpeed=40

//Do you want it to move with the page if the user scroll the page?
var tMoveOnScroll=true

//How much of the menu should be visible in the in state?
var tShow=20

/********************************************************************
Contructs the menuobjects -Object functions
*********************************************************************/
function makeMenu(obj,nest,show,move,speed){
    nest=(!nest) ? "":'document.'+nest+'.'
    this.el=bw.dom?document.getElementById(obj):bw.ie4?document.all[obj]:bw.ns4?eval(nest+'document.'+obj):0;
    this.css=bw.dom?document.getElementById(obj).style:bw.ie4?document.all[obj].style:bw.ns4?eval(nest+'document.'+obj):0;      
    this.x=this.css.left||this.css.pixelLeft||this.el.offsetLeft||0
    this.y=this.css.top||this.css.pixelTop||this.el.offsetTop||0
    this.state=1; this.go=0; this.mup=b_mup; this.show=show; this.mdown=b_mdown; 
    this.height=bw.ns4?this.css.document.height:this.el.offsetHeight
    this.moveIt=b_moveIt; this.move=move; this.speed=speed
    this.obj = obj + "Object";  eval(this.obj + "=this")    
}

// A unit of measure that will be added when setting the position of a layer.
var px = bw.ns4||window.opera?"":"px";

function b_moveIt(x,y){this.x=x; this.y=y; this.css.left=this.x+px; this.css.top=this.y+px;}
//Menu in
function b_mup(){
    if(this.y>-this.height+this.show){
        this.go=1; this.moveIt(this.x,this.y-this.move)
        setTimeout(this.obj+".mup()",this.speed)
    }else{this.go=0; this.state=1}  
}
//Menu out
function b_mdown(){
    if(this.y<eval(scrolled)){
        this.go=1; this.moveIt(this.x,this.y+this.move)
        setTimeout(this.obj+".mdown()",this.speed)
    }else{this.go=0; this.state=0}  
}
/********************************************************************************
Deciding what way to move the menu (this is called onmouseover, onmouseout or onclick)
********************************************************************************/
function moveTopMenu(num){
    if(!oMenu[num].go){
        if(!oMenu[num].state)oMenu[num].mup()   
        else oMenu[num].mdown()
    }
    for(i=0;i<oMenu.length;i++){
        if(i!=num && !oMenu[i].state){ oMenu[i].mup()}
    }
}
/********************************************************************************
Checking if the page is scrolled, if it is move the menu after
********************************************************************************/
function checkScrolled(){
    for(i=0;i<oMenu.length;i++){
        if(!oMenu[i].go){
            y=!oMenu[i].state?eval(scrolled):eval(scrolled)-oMenu[i].height+oMenu[i].show
            oMenu[i].moveIt(oMenu[i].x,y)
        }
    }
    if(bw.ns4||bw.ns6) setTimeout('checkScrolled()',40)
}
/********************************************************************************
Inits the page, makes the menu object, moves it to the right place, 
show it
********************************************************************************/
function topMenuInit(){
    oMenu=new Array()
    oMenu[0]=new makeMenu('divMenu0',"",tShow,tMove,tSpeed) 
    oMenu[1]=new makeMenu('divMenu1',"",tShow,tMove,tSpeed) //*
    //Here's an example of how you can set the properties for each menu: //*
    oMenu[2]=new makeMenu('divMenu2',"",20,10,20) //*
    //You can add as many menus you want like the line above.
    //Just remember to add the actual divs in the style and body as well.

    scrolled=bw.ns4||bw.ns6?"window.pageYOffset":"document.body.scrollTop"
    //Placing and showing menus
    for(i=0;i<oMenu.length;i++){
        oMenu[i].moveIt(oMenu[i].x,-oMenu[i].height+oMenu[i].show)
        oMenu[i].css.visibility='visible'
    }
    if(tMoveOnScroll) bw.ns4||bw.ns6?checkScrolled():window.onscroll=checkScrolled;
}

//Initing menu on pageload
onload=topMenuInit;

</script>
<div id="divMenu0">
    <a href="javascript://">子菜单1-1</a><br><br>
    <a href="javascript://">子菜单1-2</a><br><br>
    <a href="javascript://">子菜单1-3</a><br><br>
    <a href="javascript://">子菜单1-4</a><br><br>
    <a href="#" onclick="moveTopMenu(0); return false">菜单1</a>
</div>
<div id="divMenu1">
    这是第2个菜单的内容<br><br>
    <a href="#" onmouseover="moveTopMenu(1)">菜单2</a>
</div>
<div id="divMenu2">
    这是第3个菜单的内容<br>
    <a href="#" onclick="moveTopMenu(2); return false">菜单3</a>
</div>


</body>
</html>
效果图：
这里写图片描述