网页中图片大小自动调整三种方法

1.鼠标滚动图片大小调整

<body>
<script LANGUAGE="JAVASCRIPT">
function bbimg(o){
   var zoom=parseInt(o.style.zoom, 10)||100;

zoom+=event.wheelDelta/12;

if (zoom>0)

 o.style.zoom=zoom+'%';


   return false;
}
</script> 
<img src="123.jpg" onload="javascript:if(this.width>screen.width-screen.width/2) this.style.width=screen.width-screen.width/2" onmousewheel="return bbimg(this)" > 
</body>

2.图片自动缩小到固定大小

<body onload="DrawImage(theimg)">
<script language="JavaScript">
<!--
//图片按比例缩放
var flag=false;
function DrawImage(ImgD){
  var image=new Image();
  var iwidth = 320;  //定义允许图片宽度
  var iheight = 180;  //定义允许图片高度
  image.src=ImgD.src;
  if(image.width>0 && image.height>0){
   flag=true;
   if(image.width/image.height>= iwidth/iheight){
    if(image.width>iwidth){  
    ImgD.width=iwidth;
    ImgD.height=(image.height*iwidth)/image.width;
    }else{
    ImgD.width=image.width;  
    ImgD.height=image.height;
    }
    ImgD.alt=image.width+"×"+image.height;
    }
   else{
    if(image.height>iheight){  
    ImgD.height=iheight;
    ImgD.width=(image.width*iheight)/image.height;     
    }else{
    ImgD.width=image.width;  
    ImgD.height=image.height;
    }
    ImgD.alt=image.width+"×"+image.height;
    }
   }
} 
//-->
</script>
<img src="123.jpg" width="1024" height="768" name="theimg">
</body> 

3.滚轮图片缩放的代码

<script language="javascript">
var count = 10;
function resizeimg(oImage)
{ 
count = Counting(count);
Resize(oImage,count);
return false;
}
function Counting(newzoom){ 
if (event.wheelDelta >= 120)
newzoom++;
else if (event.wheelDelta <= -120)
newzoom--;
if (newzoom<2) newzoom=2; ////只允许缩小到20%
if (newzoom>50) newzoom=50; ////只允许放大到500%
return newzoom; 
}
function Resize(oImage,newzoom){ 
oImage.style.zoom = newzoom + '0%'; 
count=newzoom;
}
</script>

然后在<img src="">中加入
onDblClick="return Resize(this,10);return false;" 
onmousewheel="return resizeimg(this)"
posted @ 2008-07-12 21:21  kingkoo  阅读(7643)  评论(0)  编辑  收藏  举报