注册，上传图片，显示

上传后显示，以后显示是src直接读取数据库
post请求防止乱码

<script src="${pageContext.request.contextPath}/resourses/uploadify/jquery.uploadify.min.js" type="text/javascript"></script>
<form action="saveinfo.do" method="post"  enctype="multipart/form-data">


<tr><th width="20%">证件照</th>
            <p class="sfz"><td width="45%"><div id="preview"><img id="imghead" src="" alt=""  style="cursor: pointer;width: 100%;" /></div><br><span><input type="file" style="width: 240px;border: none;" accept=".jpg,.gif,.png,.bmp" name="identityCard1sc" onchange="previewImage(this,'preview','imghead')" />(正面)</span></td></p>
<th></th>
            <p class="sfz"><td width="45%"><div id="preview2"><img id="imghead2" src="" alt="" style="cursor: pointer;width: 100%;"/></div><br><span><input type="file" style="width: 240px;border: none;" accept=".jpg,.gif,.png,.bmp" name="identityCard2sc" onchange="previewImage(this,'preview2','imghead2')"/>(反面)</span></td></p>
</tr>

//图片上传预览    IE是用了滤镜。
function previewImage(file,preview,imghead)
{
  var MAXWIDTH  = 260;
  var MAXHEIGHT = 180;
  var div = document.getElementById(preview);
  if (file.files && file.files[0])
  {
      div.innerHTML ="<img id='"+imghead+"'>";
      var img = document.getElementById(imghead);
      img.onload = function(){
        var rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight);
        img.width  =  rect.width;
        img.height =  rect.height;
//         img.style.marginLeft = rect.left+'px';
        img.style.marginTop = rect.top+'px';
      }
      var reader = new FileReader();
      reader.onload = function(evt){img.src = evt.target.result;}
      reader.readAsDataURL(file.files[0]);
  }
  else //兼容IE
  {
    var sFilter='filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="';
    file.select();
    var src = document.selection.createRange().text;
    div.innerHTML = "<img id='"+imghead+"'>";
    var img = document.getElementById(imghead);
    img.filters.item('DXImageTransform.Microsoft.AlphaImageLoader').src = src;
    var rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight);
    status =('rect:'+rect.top+','+rect.left+','+rect.width+','+rect.height);
    div.innerHTML = "<div id=divhead style='width:"+rect.width+"px;height:"+rect.height+"px;margin-top:"+rect.top+"px;"+sFilter+src+"\'></div>";
  }
}
function clacImgZoomParam( maxWidth, maxHeight, width, height ){
    var param = {top:0, left:0, width:width, height:height};
    if( width>maxWidth || height>maxHeight )
    {
        rateWidth = width / maxWidth;
        rateHeight = height / maxHeight;
        
        if( rateWidth > rateHeight )
        {
            param.width =  maxWidth;
            param.height = Math.round(height / rateWidth);
        }else
        {
            param.width = Math.round(width / rateHeight);
            param.height = maxHeight;
        }
    }
    
    param.left = Math.round((maxWidth - param.width) / 2);
    param.top = Math.round((maxHeight - param.height) / 2);
    return param;
}