C#图片上传方法

public string PicUpLoad()
{
    string save_filePath = "/Image/nopic.gif";

    if (this.fuPic.FileName != null && this.fuPic.HasFile)
    {
        string ImgName = this.fuPic.FileName;
        string ImgExtention = System.IO.Path.GetExtension(ImgName).ToLower();
        int ImgSize = this.fuPic.PostedFile.ContentLength;//此处取得的文件大小的单位是byte

        if (ImgExtention == ".gif" || ImgExtention == ".jpg" || ImgExtention == ".jpeg")
        {
            if (ImgSize / 1024 < 1024)//转换为kb
            {
                string myTime;
                myTime = DateTime.Now.ToString("yyyyMMddHHmmss") + DateTime.Now.Millisecond.ToString("000");

                string pic_path = Server.MapPath("/Image/"); //上传文件夹

                save_filePath = pic_path + myTime + ImgExtention;

                this.fuPic.SaveAs(save_filePath); //上传文件

                save_filePath = "/Image/" + myTime + ImgExtention;
            }
            else
            {
                ClientScript.RegisterStartupScript(this.GetType(), "", "<script>alert('图片大小不能超过1M！');</script>");
                save_filePath = "0";
            }
        }
        else
        {
            ClientScript.RegisterStartupScript(this.GetType(), "", "<script>alert('图片格式不正确，只支持.gif/.jpg/.jpeg格式类型的图片！');</script>");
            save_filePath = "0";
        }
    }

    return save_filePath;
}