asp.net 庶罩层上传图片(二进制),并显示二进制图片

1.上传功能
JS检查
function hideUpImg()//关闭层，并上传图片
{
var v=document.getElementById("upImg").value;
var after=v.substring(v.lastIndexOf('.')).toLowerCase();
alert(after);
if(v.length<=0)
{
alert("请选择图片");
return false;
}
if(after==".jpg"||after==".gif"||after==".png")
{
return true;
}
alert("图片只能是.jpg .gif .png格式");
document.getElementById("upImg").outerHTML=document.getElementById("upImg").outerHTML;
return false;
}
页面代码：
<div id="myDiv" style="display: none;" mce_style="display: none;" class="divshowbottom"> </div>
<div id="upLoadImg" style="top: 200px;left: 300px;display: none;" class="divshowwork">
<div style="width: 100%; height: 20px;background-color: #FF0000; cursor: move;">上传图片</div>
<p style="text-align: center;" mce_style="text-align: center;">请上传图片</p>
<asp:FileUpload ID="upImg" runat="server" />
<asp:Label ID="lblState" runat="server" ></asp:Label>
<br /><asp:Button ID="btnUpImg" runat="server" Text="上传" OnClick="btnUpImg_Click" /> <input type="button" value="取消" id="button_2" />
</div>
后台代码:
Stream stream = this.upImg.PostedFile.InputStream;
byte[] photo = new byte[upImg.PostedFile.ContentLength];
stream.Read(photo, 0, upImg.PostedFile.ContentLength);

ItemMaster im = new ItemMaster();
im.ItemUid =Convert.ToInt32(s.Split('|')[1]);
im.Drawing = photo;
int upd = ItemMasterBIZ.UpdItemMasterByImg(im);
stream.Cl