用JavaScript實現上下文字滾動特效

　文字左右滾動的走馬燈效果是一種非常容易實現的特效，同樣的，文字上下滾動迴圈顯示也是一種非常常見而且非常容易實現的文字特效。

　具體實現方法如下：

<script language=JavaScript>
var messages=new Array()
messages[0]="<font color=#8000FF>歡迎光臨Looky's Blog!</font></a>"
messages[1]="<font color=#FB2500>這是一個用JavaScript實現上下文字滾動特效的例子</font></a>"
messages[2]="<font color=#FF0066F>希望這個例子能協助到你</font></a>"
messages[3]="<font color=#FF9900>這裡的代碼你可以隨便轉載</font></a>"
messages[4]="<font color=#00CC33>這裡的所有一切都是免費的</font></a>"
messages[5]="<font color=#000000>這裡有…………有精彩的內容等著你</font></a>"

var scrollerwidth=320
var scrollerheight=100
var scrollerbgcolor='#FFFFFF'
//下面的代碼不要改動
if (messages.length>1)
i=2
else
i=0
function move1(whichlayer){
tlayer=eval(whichlayer)
if (tlayer.top>0&&tlayer.top<=5){
tlayer.top=0
setTimeout("move1(tlayer)",3000)
setTimeout("move2(document.main.document.second)",3000)
return}
if (tlayer.top>=tlayer.document.height*-1){
tlayer.top-=5
setTimeout("move1(tlayer)",100)}
else{
tlayer.top=scrollerheight
tlayer.document.write(messages[i])
tlayer.document.close()
if (i==messages.length-1)
i=0
else
i++}}
function move2(whichlayer){
tlayer2=eval(whichlayer)
if (tlayer2.top>0&&tlayer2.top<=5){
tlayer2.top=0
setTimeout("move2(tlayer2)",3000)
setTimeout("move1(document.main.document.first)",3000)
return}
if (tlayer2.top>=tlayer2.document.height*-1){
tlayer2.top-=5
setTimeout("move2(tlayer2)",100)}
else{
tlayer2.top=scrollerheight
tlayer2.document.write(messages[i])
tlayer2.document.close()
if (i==messages.length-1)
i=0
else
i++}}
function move3(whichdiv){
tdiv=eval(whichdiv)
if (tdiv.style.pixelTop>0&&tdiv.style.pixelTop<=5){
tdiv.style.pixelTop=0
setTimeout("move3(tdiv)",3000)
setTimeout("move4(second2)",3000)
return}
if (tdiv.style.pixelTop>=tdiv.offsetHeight*-1){
tdiv.style.pixelTop-=5
setTimeout("move3(tdiv)",100)}
else{
tdiv.style.pixelTop=scrollerheight
tdiv.innerHTML=messages[i]
if (i==messages.length-1)
i=0
else
i++}}
function move4(whichdiv){
tdiv2=eval(whichdiv)
if (tdiv2.style.pixelTop>0&&tdiv2.style.pixelTop<=5){
tdiv2.style.pixelTop=0
setTimeout("move4(tdiv2)",3000)
setTimeout("move3(first2)",3000)
return}
if (tdiv2.style.pixelTop>=tdiv2.offsetHeight*-1){
tdiv2.style.pixelTop-=5
setTimeout("move4(second2)",100)}
else{
tdiv2.style.pixelTop=scrollerheight
tdiv2.innerHTML=messages[i]
if (i==messages.length-1)
i=0
else
i++}}
function startscroll(){
if (document.all){
move3(first2)
second2.style.top=scrollerheight}
else if (document.layers){
move1(document.main.document.first)
document.main.document.second.top=scrollerheight+5
document.main.document.second.visibility='show'}}
window.onload=startscroll
</script>
<ilayer id="main" width=&{scrollerwidth}; height=&{scrollerheight};
bgcolor=&{scrollerbgcolor};>
<layer id="first" left=0 top=1 width=&{scrollerwidth};>
<script language="JavaScript1.2">
if (document.layers)
document.write(messages[0])
</script>
</layer>
<layer id="second" left=0 top=0 width=&{scrollerwidth}; visibility=hide>
<script language="JavaScript1.2">
if (document.layers)
document.write(messages[1])
</script>
</layer>
</ilayer>
<script language="JavaScript1.2">
if (document.all){
document.writeln('<span id="main2" style="position:relative;width:'+scrollerwidth+';height:'
+scrollerheight+';overflow:hiden;background-color:'+scrollerbgcolor+'">')
document.writeln('<div style="position:absolute;width:'+scrollerwidth+';height:'
+scrollerheight+';clip:rect(0 '+scrollerwidth+' '
+scrollerheight+' 0);left:0;top:0">')
document.writeln('<div id="first2" style="position:absolute;width:'+scrollerwidth+';left:0;top:1;">')
document.write(messages[0])
document.writeln('</div>')
document.writeln('<div id="second2" style="position:absolute;width:'+scrollerwidth+';left:0;top:0">')
document.write(messages[1])
document.writeln('</div>')
document.writeln('</div>')
document.writeln('</span>')
}
</script>

(在需要添加該特效的網頁具體位置中粘貼如下代碼即可)

　　注意：代碼中的“var scrollerwidth=320”表示迴圈框寬度，"var scrollerheigh=100"表示迴圈框高度，"font color=# "代表文字顏色，可以根據需要進行修改。