<!--解读 M$ 源代码:JavaScript + CSS 实现层的平移及动态显示--> <!--Open.htm--> <!--本文主要由 JavaScript 和 CSS 实现的层的平移及动态显示--> <!--小弟的 JavaScript 水平实在有够差劲,故以下注解均为个人理解,有疏漏及不当之处还请各位大虾指正--> <!--以下源代码来源于 M$ Windows 2000 Professional 安装光盘的 DISCOVER 目录,更改之处见文档的最有注解-->
<SCRIPT language="javascript"> var StartV = 0.5; var EndV = 1; var MidV; var Inc = 0.12; var Power = 3; /* Inc 与 Power 共同控制每循环 alpha 的变化量及循环总个数*/ var mSec = 20; var SlStartV; var SlEndV; var SlInc; var mSec; var openSec = 20;//控制循环完成所需时间 var SlPower;
function fadeLogo() { if (EndV > .9999) { StartV = StartV + Inc; MidV = Math.sin(StartV) + 1; EndV = Math.pow(MidV,Power); /*个人认为采用形如“int i;i=1;i++”的方式定义 EndV,亦可达到 alpha 变化的效果,但是那样只是匀速变化,不及此处使用的具有动感罢了*/ document.all.brandLogo.filters.alpha.opacity = document.all.brandLogo.filters.alpha.opacity + EndV ; document.all.Discover.filters.alpha.opacity = document.all.Discover.filters.alpha.opacity + EndV ; document.all.Marketing.filters.alpha.opacity = document.all.Marketing.filters.alpha.opacity + EndV; /*为实现 alpha 与平移的连续性,亦可在 EndV 后加一个常量,这样控制会容易一些*/ //alert(document.all.Discover.filters.alpha.opacity); /*如我一般的菜鸟,可采用 alert 的方法跟踪某个变量,以达到所需的效果,只是小心不要出现死循环,到时候别骂我哦~~ 本例中跟踪了 alpha 的值,100只出现一次便是我要的效果,即 alpha 与平移的连续*/ timer = window.setTimeout("fadeLogo();", openSec, "JavaScript"); } else { SlStartV = 0.5; SlEndV = 1; SlInc = 0.055; SlPower = 4; mSec = 30; /*变量赋值,以适应下次调用的需求。 SlInc 与 SlPower 共同控制每循环位置的变化量及循环总个数*/ openSlide();//调用 openSlide(),平移开始。注1。 } }
function openSlide() { if (SlEndV > .9999) { SlStartV = SlStartV + SlInc; SlMidV = Math.sin(SlStartV) + 1; SlEndV = Math.pow(SlMidV,SlPower); /*跟上边一样,没什么好说的,除了我不懂 Math.pow 以外*/ Plane.style.posTop = Plane.style.posTop - SlEndV; if (Plane.style.posTop < 150) {Marketing.style.display = "none"}//隐蔽被遮蔽层,当上移层高度超过他的高度的时候。可通过改变条件得到最佳效果。 timer = window.setTimeout("openSlide();", mSec, "JavaScript"); } else { Blank.style.display = "none";//隐藏空白层(Blank),见下面关于空白层的说明 SlStartV = 0.5; SlEndV = 1; SlInc = 0.09; mSec = 30; SlPower = 3 /*变量重赋值,其余没什么好说的,跟上边一样*/ navSlide(); } }
function navSlide() { if (SlEndV > .9999) { SlStartV = SlStartV + SlInc; SlMidV = Math.sin(SlStartV) + 1; SlEndV = Math.pow(SlMidV,SlPower); TOC.style.posLeft = TOC.style.posLeft + SlEndV; timer = window.setTimeout("navSlide();", mSec, "JavaScript"); } else { SlStartV = 0.5; SlEndV = 1; SlInc = 0.05; mSec = 30; SlPower = 4; menu1Slide(); } } function menu1Slide() { if (SlEndV > .9999) { SlStartV = SlStartV + SlInc; SlMidV = Math.sin(SlStartV) + 1; SlEndV = Math.pow(SlMidV,SlPower); Menu1.style.posTop = Menu1.style.posTop + SlEndV; timer = window.setTimeout("menu1Slide();", mSec, "JavaScript"); } else {
SlStartV = 0.5; SlEndV = 1; SlInc = 0.05; mSec = 30; SlPower = 4; menu2Slide(); } }
function menu2Slide() { if (SlEndV > .9999) { SlStartV = SlStartV + SlInc; SlMidV = Math.sin(SlStartV) + 1; SlEndV = Math.pow(SlMidV,SlPower); Menu2.style.posTop = Menu2.style.posTop + SlEndV; timer = window.setTimeout("menu2Slide();", mSec, "JavaScript"); } else { SlStartV = 0.5; SlEndV = 1; SlInc = 0.05; mSec = 30; SlPower = 4; menu3Slide(); } }
function menu3Slide() { if (SlEndV > .9999) { SlStartV = SlStartV + SlInc; SlMidV = Math.sin(SlStartV) + 1; SlEndV = Math.pow(SlMidV,SlPower); Menu3.style.posTop = Menu3.style.posTop + SlEndV; timer = window.setTimeout("menu3Slide();", mSec, "JavaScript"); } else { SlStartV = 0.5; SlEndV = 1; SlInc = 0.05; mSec = 30; SlPower = 4; menu4Slide(); } }
function menu4Slide() { if (SlEndV > .9999) { SlStartV = SlStartV + SlInc; SlMidV = Math.sin(SlStartV) + 1; SlEndV = Math.pow(SlMidV,SlPower); Menu4.style.posTop = Menu4.style.posTop + SlEndV; timer = window.setTimeout("menu4Slide();", mSec, "JavaScript"); } else { SlStartV = 0.5; SlEndV = 1; SlInc = 0.05; mSec = 30; SlPower = 4; return; } }
</SCRIPT> <Body bgcolor="White" onload="fadeLogo();this.focus(); " leftmargin="0" topmargin="0"> <!--注2--> <table> <tr> <td align="center"> <IMG ID="brandLogo" style="filter:alpha(opacity=0)" class="Brand" src=http://cfan.net.cn/info/"images/banner.gif" width="480" height="60" border="0" alt="" style="position:absolute; left: 143; top: 0;"> <!--style="filter:alpha(opacity=0)":定义初始 alpha 值为 0,下同。 --> <DIV ID="Plane" style="position:absolute; left: 0; top: 552;"> <IMG ID="Discover" src=http://cfan.net.cn/info/"images/fengexian.gif" width="762" height="20" border="0" alt="" style="filter:alpha(opacity=0);"> <IMG ID="Blank" src=http://cfan.net.cn/info/"images/blank.gif" width="562" style="position: relative; top: -4" height="300" border="0" alt=""> <!-- 当上移层(Discover)的下边线超过被遮蔽层(Marketing)的下边线时,为了不让被遮蔽层(Marketing)被看到,需要用一个空白层(Blank)来遮蔽。空白层到达指定位置后需要隐藏。 如果上移层(Discover)的高度大于被遮蔽层(Marketing),则不会出现这种情况,此时,不需要空白层(Blank)--> <br> </DIV> <IMG ID="Marketing" src=http://cfan.net.cn/info/"images/ad.gif" width="562" height="526" border="0" alt="" style="position:absolute; left: 200; top: 60; display:block; filter:alpha(opacity=0); z-index:-1"> <DIV ID="TOC" style="background-image: url(images/leftback.gif); width:200; height:524;position:absolute; top:62; left:-200; z-index:-2"> <IMG SRC=http://cfan.net.cn/info/"images/welcome.gif" ID="DisTxt" style="position:absolute; top:10; left:-20;" width="200" height="560" border="0" alt="" hspace="2" vspace="2"> </DIV> <A target="_self" href="jiaocheng/default.htm" onclick="top.TopMain.Main.location='jiaocheng/default.htm'" onmouseOver="javascript:document.all.Menu1.filters.alpha.opacity = 100;" onmouseOut="javascript:document.all.Menu1.filters.alpha.opacity = 50;"> <!--onmouseOver="javascript:document.all.Menu1.filters.alpha.opacity = 100;" onmouseOut="javascript:document.all.Menu1.filters.alpha.opacity = 50;":定义鼠标悬停与否使对象的 alpha 值改变,下同。注3--> <DIV ID="Menu1" style="position:absolute; top:-400; left:260; z-index:-2;filter:alpha(opacity=50);cursor:hand;"> <!--cursor:hand;:定义悬停时鼠标形状为手型,下同。注4--> <TABLE border="0" cellspacing="0" cellpadding="0" style="font-size: 12; font-family: Arial; font-weight: bold;"> <tr> <td> <IMG src=http://cfan.net.cn/info/"images/jiaocheng.gif" width="60" height="60" border="0" alt="" hspace="10" align="10"> </td> <td> <IMG ID="User" src=http://cfan.net.cn/info/"images/jiaocheng1.gif" width="200" height="50" border="0" alt="" vspace="1"> <br> <IMG src=http://cfan.net.cn/info/"images/xian.gif" width="249" height="2" border="0" alt=""> </td> </tr> </TABLE> </DIV> </A><A target="_self" href="wuxia/default.htm" onclick="top.TopMain.Main.location='wuxia/default.htm'" onmouseOver="javascript:document.all.Menu2.filters.alpha.opacity = 100;" onmouseOut="javascript:document.all.Menu2.filters.alpha.opacity = 50;"> <DIV ID="Menu2" style="position:absolute; top:-310; left:260; z-index:-2;filter:alpha(opacity=50);cursor:hand;"> <TABLE border="0" cellspacing="0" cellpadding="0" style="font-size: 12; font-family: Arial; font-weight: bold;"> <tr> <td> <IMG src=http://cfan.net.cn/info/"images/wuxia.gif" width="60" height="60" border="0" alt="" hspace="10" vspace="10"> </td> <td> <IMG ID="Manage" src=http://cfan.net.cn/info/"images/wuxia1.gif" width="200" height="50" border="0" alt="" vspace="1"> <br> <IMG src=http://cfan.net.cn/info/"images/xian.gif" width="249" height="2" border="0" alt=""> </td> </tr> </TABLE> </DIV> </A><A target="_self" href="wangluo/default.htm" onclick="top.TopMain.Main.location='wangluo/default.htm'" onmouseOver="javascript:document.all.Menu3.filters.alpha.opacity = 100;" onmouseOut="javascript:document.all.Menu3.filters.alpha.opacity = 50;"> <DIV ID="Menu3" style="position:absolute; top:-210; left:260; z-index:-2;filter:alpha(opacity=50);cursor:hand;"> <TABLE border="0" cellspacing="0" cellpadding="0" style="font-size: 12; font-family: Arial; font-weight: bold;"> <tr> <td> <IMG src=http://cfan.net.cn/info/"images/wangluo.gif" width="60" height="60" border="0" alt="" hspace="10" vspace="10"> </td> <td> <IMG ID="Manage" src=http://cfan.net.cn/info/"images/wangluo1.gif" width="200" height="50" border="0" alt="" vspace="1"> <br> <IMG src=http://cfan.net.cn/info/"images/xian.gif" width="249" height="2" border="0" alt=""> </td> </tr> </TABLE> </DIV> </A><A target="_self" href="kaixin/default.htm" onclick="top.TopMain.Main.location='kaixin/default.htm'" onmouseOver="javascript:document.all.Menu4.filters.alpha.opacity = 100;" onmouseOut="javascript:document.all.Menu4.filters.alpha.opacity = 50;"> <DIV ID="Menu4" style="position:absolute; top:-100; left:260; z-index:-2;filter:alpha(opacity=50);cursor:hand;"> <TABLE border="0" cellspacing="0" cellpadding="0" style="font-size: 12; font-family: Arial; font-weight: bold;"> <tr> <td> <IMG src=http://cfan.net.cn/info/"images/kaixin.gif" width="60" height="60" border="0" alt="" hspace="10" vspace="10"> </td> <td> <IMG ID="Manage" src=http://cfan.net.cn/info/"images/kaixin1.gif" width="200" height="50" border="0" alt="" vspace="1"> <br> <IMG src=http://cfan.net.cn/info/"images/xian.gif" width="249" height="2" border="0" alt=""> </td> </tr> </TABLE> </DIV> </A> </td> </tr>
</Body> <!-- 注1:原(M$)代码中使用"timer = window.setTimeout("openSlide();", mSec, "JavaScript");"来调用下一个过程的,个人认为没有什么意义,所以改为直接调用"openSlide()",以下均是如此。 注2:原(M$)代码中包含有调用声音的函数,本文已全部略去。 注3:原(M$)代码中鼠标悬停时调用的是另一幅图像,本文中改为更改对象的 alpha 值而得到理想的效果,下同。 注4:原(M$)代码是在 IMG 对象中说明 cursor:hand ,本文改为在 DIV 对象中说明,下同。 以上代码中可以看出,JavaScript 动态生成变量,用以随时间改变层的绝对定位坐标,以实现层的位移;而使用 CSS 的滤镜 alpha ,随时间改变对象的 alpha 值,即可实现层的动态显示。 相同的效果由 Flash 亦可实现,至于哪种方式更快些,,更加适合网页的应用,因为没有测试,所以我就不知道了~~ --> <!--CopyRight By Cheery_Ke,04-07-2002,All Reserved-->
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