1 <script language="JavaScript"> 2 <!-- 3 var srcX = 1024; //原图长宽 4 var srcY = 768; 5 var bigX = 500; //原比例预览大小,可以设置成任意大小 6 var bigY = 300; 7 var smallX = 256; //缩略图大小,要与原大小成比例 8 var smallY = 192; 9 var viewX = bigX / srcX * smallX; //预览范围 10 var viewY = bigY / srcY * smallY; 11 var bl = srcX / smallX;//缩小比例 12 var border = 8; //边框 13 window.onload=function (){ 14 bigbox.style.borderWidth=border; 15 bigbox.style.width=bigX+border*2; 16 bigbox.style.height=bigY+border*2; 17 smallpic.width=smallX; 18 smallpic.height=smallY; 19 view.style.width=viewX; 20 view.style.height=viewY; 21 smallbox.style.borderWidth=border; 22 if (window.event){ 23 smallbox.style.width=smallpic.offsetWidth+border*2; 24 smallbox.style.height=smallpic.offsetHeight+border*2; 25 }else{ 26 smallbox.style.width=smallpic.offsetWidth; 27 smallbox.style.height=smallpic.offsetHeight; 28 } 29 move(event); 30 } 31 function move(e){ 32 var e = window.event?window.event:e; 33 var iebug = 0; 34 if (window.event){ 35 var vX = e.offsetX - viewX/2; 36 var vY = e.offsetY - viewY/2; 37 }else{ 38 var vX = e.pageX - viewX/2 - smallbox.offsetLeft - border; 39 var vY = e.pageY - viewY/2 - smallbox.offsetTop - border; 40 iebug = 2; 41 } 42 if (vX < 0) vX = 0; 43 if (vY < 0) vY = 0; 44 if (vX > smallX - viewX - iebug) vX = smallX - viewX - iebug; 45 if (vY > smallY - viewY - iebug) vY = smallY - viewY - iebug; 46 view.style.left = vX + smallbox.offsetLeft + border; 47 view.style.top = vY + smallbox.offsetTop + border; 48 bigbox.style.backgroundPosition= - vX * bl + " " + -vY * bl; 49 } 50 //--> 51 </script> 52 53 <style type="text/css"> 54 <!-- 55 *{padding:0;margin:0} 56 img{display:block;} 57 #smallbox{border:1px #c33 solid;float:left;width:0;height:0;overflow:hidden} 58 #bigbox{border:1px #c33 solid;width:0px;height:0px;float:left;background:url('/upload/20071130224657571.jpg') no-repeat;} 59 #view{border:1px #ddd solid;width:0px;height:0px;position:absolute} 60 .head{text-align:center;line-height:40px;font:bold 16px/40px;color:red} 61 //--> 62 </style> 63 <div class="head">图片放大效果</div> 64 <div id="smallbox"><img id="smallpic" src="/upload/20071130224657571.jpg" border="0" onmousemove="move(event)"></div> 65 <div id="bigbox"></div> 66 <div id="view"></div>
代码最终的效果如下图：
