上传大小2张图片
protected void submit_Click(object sender, EventArgs e)
  {
  string Status = "";
  string bigimage = "";
  string smallimage = "";
  bool status;

  if (fileUpload.HasFile)
  {
  // 设置上传目录全路径
  string path = "~/UploadFiles/images/";
  string uploadPath = Server.MapPath("~/UploadFiles/images/");
  //图片名称
  string imgName = DateTime.Now.ToString("yyyyMMddhhmmss");  
  string[] resArr = Tu_BLL.UploadImg(uploadPath, fileUpload, imgName,path);
  Status = resArr.GetValue(0).ToString();
  bigimage = resArr.GetValue(1).ToString();
  //smallimage = resArr.GetValue(1).ToString();
  }
  if (fileUpload1.HasFile)
  {
  // 设置上传目录全路径
  string path = "~/UploadFiles/images/";
  string uploadPath = Server.MapPath("~/UploadFiles/images/");
  //图片名称
  string imgName = DateTime.Now.ToString("yyyyMMddhh");
  string[] resArr = Tu_BLL.UploadImg(uploadPath, fileUpload, imgName, path);
  Status = resArr.GetValue(0).ToString();
  //bigimage = resArr.GetValue(1).ToString();
  smallimage = resArr.GetValue(1).ToString();
  }
  if (Request["id"] != "0")
  {
  string oldimageSourceA = Server.MapPath(Tu_BLL.imageSelectForID(int.Parse(Request["id"]))[0].bigimage);
  string oldimageSourceB = Server.MapPath(Tu_BLL.imageSelectForID(int.Parse(Request["id"]))[0].smallimage);
  if (bigimage == "")
  {
  bigimage = Tu_BLL.imageSelectForID(int.Parse(Request["id"]))[0].bigimage;
   
  }
  if (smallimage == "")
  {
   
  smallimage = Tu_BLL.imageSelectForID(int.Parse(Request["id"]))[0].smallimage;
  }
  else
  {
  Tu_BLL.DeleteFile(oldimageSourceA);
  Tu_BLL.DeleteFile(oldimageSourceB);
  }
  status = Tu_BLL.UpdateImg(bigimage, smallimage, title.Text, int.Parse(Request["id"]));
  }
  else
  {
  status = Tu_BLL.ImageListInsertB(int.Parse(Request["uid"]), bigimage, smallimage, title.Text);
  }
  if (status) { Server.Transfer("page.aspx?uid=" + Request["uid"]); }
  }
  }
}

------解决方案--------------------
/// <summary>
/// 缩小图片
/// </summary>
/// <param name="strOldPic">源图文件名(包括路径)</param>
/// <param name="strNewPic">缩小后保存为文件名(包括路径)</param>
/// <param name="intWidth">缩小至宽度</param>
/// <param name="intHeight">缩小至高度</param>
public void SmallPic(string strOldPic, string strNewPic, int intWidth, int intHeight)
{
<