轉載:http://www.cnblogs.com/chenjt/p/4193464.html
主要用到dom.offsetWidth 這個表示實際的寬度。
dom.scrollLeft 這個表示這個容器dom的滾動條的水平偏移.
核心代碼:
<!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> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>向上下左右不間斷無縫滾動圖片的效果(兼容火狐和IE)</title> </head> <body> <div id="colee" style="overflow:hidden;height:253px;width:410px;"> <div id="colee1"> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> </div> <div id="colee2"></div> </div> <script> var speed=30; var colee2=document.getElementById("colee2"); var colee1=document.getElementById("colee1"); var colee=document.getElementById("colee"); colee2.innerHTML=colee1.innerHTML; //克隆colee1為colee2 function Marquee1(){ //當滾動至colee1與colee2交界時 if(colee2.offsetTop-colee.scrollTop<=0){ colee.scrollTop-=colee1.offsetHeight; //colee跳到最頂端 }else{ colee.scrollTop++ } } var MyMar1=setInterval(Marquee1,speed)//設置定時器 //鼠標移上時清除定時器達到滾動停止的目的 colee.onmouseover=function() {clearInterval(MyMar1)} //鼠標移開時重設定時器 colee.onmouseout=function(){MyMar1=setInterval(Marquee1,speed)} </script> <!--向上滾動代碼結束--> <br> <div style="height: 100px;background: pink;">這個上下之間的空白,</div> <!--下面是向下滾動代碼--> <div id="colee_bottom" style="overflow:hidden;height:253px;width:410px;"> <div id="colee_bottom1"> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> <p><img src="http://www.le.com/favicon.ico"></p> </div> <div id="colee_bottom2"></div> </div> <script> var speed=30; var colee_bottom2=document.getElementById("colee_bottom2"); var colee_bottom1=document.getElementById("colee_bottom1"); var colee_bottom=document.getElementById("colee_bottom"); colee_bottom2.innerHTML=colee_bottom1.innerHTML colee_bottom.scrollTop=colee_bottom.scrollHeight function Marquee2(){ if(colee_bottom1.offsetTop-colee_bottom.scrollTop>=0) colee_bottom.scrollTop+=colee_bottom2.offsetHeight else{ colee_bottom.scrollTop-- } } var MyMar2=setInterval(Marquee2,speed) colee_bottom.onmouseover=function() {clearInterval(MyMar2)} colee_bottom.onmouseout=function() {MyMar2=setInterval(Marquee2,speed)} </script> <!--向下滾動代碼結束--> <br> <!--下面是向左滾動代碼--> <div id="colee_left" style="overflow:hidden;width:252px;"> <table cellpadding="0" cellspacing="0" border="0"> <tr><td id="colee_left1" valign="top" align="center"> <table cellpadding="2" cellspacing="0" border="0"> <tr align="center"> <td><p><img src="http://www.le.com/favicon.ico"></p></td> <td><p><img src="http://www.le.com/favicon.ico"></p></td> <td><p><img src="http://www.le.com/favicon.ico"></p></td> <td><p><img src="http://www.le.com/favicon.ico"></p></td> <td><p><img src="http://www.le.com/favicon.ico"></p></td> <td><p><img src="http://www.le.com/favicon.ico"></p></td> <td><p><img src="http://www.le.com/favicon.ico"></p></td> </tr> </table> </td> <td id="colee_left2" valign="top"></td> </tr> </table> </div> <script> //使用div時,請保證colee_left2與colee_left1是在同一行上. var speed=100;//速度數值越大速度越慢 var colee_left2=document.getElementById("colee_left2"); var colee_left1=document.getElementById("colee_left1"); var colee_left=document.getElementById("colee_left"); colee_left2.innerHTML=colee_left1.innerHTML function Marquee3(){ if(colee_left2.offsetWidth-colee_left.scrollLeft<=0){//offsetWidth 是對象的可見寬度 colee_left.scrollLeft-=colee_left1.offsetWidth//scrollWidth 是對象的實際內容的寬,不包邊線寬度 } else{ colee_left.scrollLeft++; console.log("colee_left.scrollLeft"+colee_left.scrollLeft); } } var MyMar3=setInterval(Marquee3,speed) colee_left.onmouseover=function() {clearInterval(MyMar3)} colee_left.onmouseout=function() {MyMar3=setInterval(Marquee3,speed)} </script> <!--向左滾動代碼結束--> <br> <!--下面是向右滾動代碼--> <div id="colee_right" style="overflow:hidden;width:252px;"> <table cellpadding="0" cellspacing="0" border="0"> <tr><td id="colee_right1" valign="top" align="center"> <table cellpadding="2" cellspacing="0" border="0"> <tr align="center"> <td><p><img src="http://www.le.com/favicon.ico"></p></td> <td><p><img src="http://www.le.com/favicon.ico"></p></td> <td><p><img src="http://www.le.com/favicon.ico"></p></td> <td><p><img src="http://www.le.com/favicon.ico"></p></td> <td><p><img src="http://www.le.com/favicon.ico"></p></td> </tr> </table> </td> <td id="colee_right2" valign="top"></td> </tr> </table> </div> <script> var speed=30;//速度數值越大速度越慢 var colee_right2=document.getElementById("colee_right2"); var colee_right1=document.getElementById("colee_right1"); var colee_right=document.getElementById("colee_right"); colee_right2.innerHTML=colee_right1.innerHTML function Marquee4(){ if(colee_right.scrollLeft<=0) colee_right.scrollLeft+=colee_right2.offsetWidth else{ colee_right.scrollLeft-- } } var MyMar4=setInterval(Marquee4,speed) colee_right.onmouseover=function() {clearInterval(MyMar4)} colee_right.onmouseout=function() {MyMar4=setInterval(Marquee4,speed)} </script> <!--向右滾動代碼結束--> </body> </html>
我自己寫的發現向上沒有使用offsetTop也行,反正原理都是等scrollTop和第一個的位移一樣的時候,把scrollTop=0就行。

<!DOCTYPE html> <html> <head> <title></title> <style type="text/css"> *{margin:0;padding: 0} #yan>div>div{ display: inline-block; } #yan ul li { display: inline-block; } </style> </head> <body> <div id="yan" style="width:320px; overflow: hidden;"> <div style="width:644px; "> <div id="yan1"> <ul> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> </ul> </div> <div id="yan2"> </div> </div> </div> <hr/> <div id="shang" style="height:306px; overflow-y: hidden;"> <div style="height:612px; "> <div id="shang1"> <ul> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> <li><img src="http://www.le.com/favicon.ico"></li> </ul> </div> <div id="shang2"> </div> </div> </div> <script type="text/javascript"> var box1 = document.querySelector("#yan1"); var box2 = document.querySelector("#yan2"); var box = document.querySelector("#yan"); box2.innerHTML = box1.innerHTML; //向左 function left(){ if(box2.offsetWidth - box.scrollLeft <=0){ box.scrollLeft -= box1.offsetWidth; }else{ box.scrollLeft++; } } //向右 function right(){ if(box.scrollLeft <=0){ box.scrollLeft += box1.offsetWidth; }else{ box.scrollLeft--; } } //向上 /*function top(){ if(box.scrollLeft <=0){ box.scrollLeft += box1.offsetWidth; }else{ box.scrollLeft--; } }*/ var shang1 = document.querySelector("#shang1"); var shang2 = document.querySelector("#shang2"); var shang = document.querySelector("#shang"); shang2.innerHTML = shang1.innerHTML; shang.scrollTop = shang1.offsetHeight; //向下 function down(){ if(shang.scrollTop <=0){ shang.scrollTop+= shang1.offsetHeight; }else{ shang.scrollTop--; } } //向上 function up(){ if(shang1.offsetHeight - shang.scrollTop <=0){ shang.scrollTop -= shang1.offsetHeight; }else{ shang.scrollTop++; } } setInterval(up,20); </script> </body> </html>
這里我們需要知道offsetTop offsetHeight scrollTop的區別
1、scrollTop:https://developer.mozilla.org/en-US/docs/DOM/element.scrollTop
比較容易理解,一個可讀寫的屬性
1)element.scrollTop 返回該元素當前垂直滾動的距離,比如100(無單位)
2)element.scrollTop = 100 將該元素垂直滾動的距離設置為100,注意100為絕對值,而不是相對值。比如當前元素垂直滾動距離 element.scrollTop = 200,則設置完后,該元素垂直滾動的距離為100,而不是100+200
2、offsetTop:https://developer.mozilla.org/en-US/docs/DOM/element.offsetTop
返回該元素相對於其offsetParent頂部的距離,至於offsetParent,指的是距離該元素最近的定位元素,如下所示
<div id="p"><a> <span id="c"></span> </a></div>, P為C的offsetParent,offsetTop則為C距離P頂部的距離
這里有一個寫的比較簡單的例子:
<<!DOCTYPE html> <html> <head> <title></title> <style type="text/css"> #marquee { position: relative; height: 300px; width: 200px; overflow: hidden; border: 10px solid #369; padding:0; margin:0; } #marquee img { display: block; } #marquee dd { margin: 0px; padding: 0px; } </style> </head> <body> <dl id="marquee"> <dt> <img src="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/o_s017.jpg" alt="無縫滾動" /> <img src="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/o_s018.jpg" alt="無縫滾動" /> <img src="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/o_s019.jpg" alt="無縫滾動" /> <img src="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/o_s020.jpg" alt="無縫滾動" /> <img src="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/o_s021.jpg" alt="無縫滾動" /> <img src="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/o_s022.jpg" alt="無縫滾動" /> <img src="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/o_s023.jpg" alt="無縫滾動" /> </dt> <dd> </dd> </dl> <script type="text/javascript"> var Marquee = function (id) { var container = document.getElementById(id), original = container.getElementsByTagName("dt")[0], clone = container.getElementsByTagName("dd")[0], speed = arguments[1] || 10; clone.innerHTML = original.innerHTML; alert(container.scrollTop); var rolling = function () { if (container.scrollTop == clone.offsetTop) { //我現在糾結的就是container.scrollTop和clone.offsetTop的區別 // 為什么clone.offsetTop是1050,而外面的container.scrollTop卻是0 container.scrollTop = 0; } else { container.scrollTop++; } } var timer = setInterval(rolling, speed) container.onmouseover = function () { clearInterval(timer) } container.onmouseout = function () { timer = setInterval(rolling, speed) } } window.onload = function () { Marquee("marquee"); } </script> </body> </html>