上传图片

<script language="javascript" type="text/javascript">
   function PreviewImg(imgFile)
{    
    var newPreview = document.getElementById("newPreview");
        newPreview.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src   = 
imgFile.value;
    newPreview.style.width = "80px";
    newPreview.style.height = "60px";
}

</script>

<asp:FileUpload ID="Fud_Pic" runat="server" Width="300px" /><div id="newPreview"></div>

//上传图片
        string picPath = "";
        if (Fud_Pic.HasFile)
        {
            if (Fud_Pic.PostedFile.ContentLength > 204800)
            {
                Response.Write("<script>alert('上传图片不得超过 200k！')</script>");
                return;

            }

            string fileContentType = Fud_Pic.PostedFile.ContentType;
            if (fileContentType == "image/gif" || fileContentType == "image/pjpeg"||fileContentType 
== "image/bmp" )
            {

                                string fileName = DateTime.Now.Date.ToShortDateString().Replace("-", "") + 
DateTime.Now.ToLongTimeString().Replace(":", "") + DateTime.Now.Millisecond + ".gif";
                string webFilePath = Server.MapPath(@"~\upfiles\")  + fileName;  //图片上传路径
                string sFilePath = Server.MapPath(@"~\upfiles\")  + fileName.Replace(".gif",".jpg"); 
//缩略图路径
                picPath = @"\upfiles\" + fileName;   //写入数据库路径
                Fud_Pic.SaveAs(webFilePath);
                MakeThumbnail(webFilePath, sFilePath, 130, 130, "H");     // 生成缩略图方法

            }