jquery插件ajaxupload实现文件上传操作

/// 文档上传
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
private string UploadFile(HttpContext context)
{
int cout = context.Request.Files.Count;
if (cout > 0)
{
HttpPostedFile hpf = context.Request.Files[0];
if (hpf != null)
{
string fileExt = Path.GetExtension(hpf.FileName).ToLower();
//只能上传文件，过滤不可上传的文件类型
string fileFilt = ".rar|.zip|.pdf|.pdfx|.txt|.csv|.xls|.xlsx|.doc|.docx......";
if (fileFilt.IndexOf(fileExt) <= -1)
{
return "1";
}

//判断文件大小
int length = hpf.ContentLength;
if (length > 2097152)
{
return "2";
}

Random rd = new Random();
DateTime nowTime = DateTime.Now;
string newFileName = nowTime.Year.ToString() + nowTime.Month.ToString() + nowTime.Day.ToString() + nowTime.Hour.ToString() + nowTime.Minute.ToString() + nowTime.Second.ToString() + rd.Next(1000, 1000000) + Path.GetExtension(hpf.FileName);
if (!Directory.Exists(_filedir))
{
Directory.CreateDirectory(_filedir);
}
string fileName = _filedir + newFileName;
hpf.SaveAs(fileName);
return newFileName;
}

}
return "3";
}

/// <summary>
/// 图片上传
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
private string UploadImg(HttpContext context)
{
int cout = context.Request.Files.Count;
if (cout > 0)
{
HttpPostedFile hpf = context.Request.Files[0];
if (hpf != null)
{
string fileExt = Path.GetExtension(hpf.FileName).ToLower();
//只能上传文件，过滤不可上传的文件类型
string fileFilt = ".gif|.jpg|.php|.jsp|.jpeg|.png|......";
if (fileFilt.IndexOf(fileExt) <= -1)
{
return "1";
}

//判断文件大小
int length = hpf.ContentLength;
if (length > 204800)
{
return "2";
}

Random rd = new Random();
DateTime nowTime = DateTime.Now;
string newFileName = nowTime.Year.ToString() + nowTime.Month.ToString() + nowTime.Day.ToString() + nowTime.Hour.ToString() + nowTime.Minute.ToString() + nowTime.Second.ToString() + rd.Next(1000, 1000000) + Path.GetExtension(hpf.FileName);
if (!Directory.Exists(_filedir))
{
Directory.CreateDirectory(_filedir);
}
string fileName = _filedir + newFileName;
hpf.SaveAs(fileName);
return newFileName;
}

}
return "3";
}

#region IHttpHandler 成员

public bool IsReusable
{
get { throw new NotImplementedException(); }
}

#endregion
}

附件1：页面CSS样式