c#上传图片

private string uploadPic()

    {

        string ImageURL = "";

        //检测一下uploadFile是否选择了上传文件

        if (uploadFile.HasFile)

        {

            //检测一下目录是否存在

            if (!Directory.Exists(HttpContext.Current.Request.PhysicalApplicationPath + "upImages//adv//"))

            {

                Directory.CreateDirectory(HttpContext.Current.Request.PhysicalApplicationPath + "upImages//adv//");

            }

            string savePath = @"\upImages\adv\";

            if (uploadFile.HasFile)

            {

                savePath += uploadFile.FileName;

            }

            if (!File.Exists(HttpContext.Current.Request.PhysicalApplicationPath + "upImages//adv//" + uploadFile.FileName))

            {

                string[] allowesExtensions = { ".gif", ".png", ".bmp", ".jpg" };

                string fileEctension = System.IO.Path.GetExtension(uploadFile.FileName).ToLower();

                bool fileOK = false;

                for (int i = 0; i < allowesExtensions.Length; i++)

                {



                    if (fileEctension == allowesExtensions[i])

                    {



                        fileOK = true;



                    }



                }

                if (!fileOK)

                {

                    lblPicMsg.Visible = true;

                    lblPicMsg.Text = "不支持该类型的文件";

                }

                else

                {

                    if (uploadFile.FileContent.Length / 1024 > 4096)

                    {

                        lblPicMsg.Visible = true;

                        lblPicMsg.Text = "上传文件大小限制为 4MB !";

                    }

                    else

                    {

                        string AutoName = "GTT" + DateTime.Now.ToShortDateString().Replace("-", "") + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + System.IO.Path.GetExtension(uploadFile.FileName).ToString();

                        string path = Server.MapPath("~") + @"\upImages\adv\" + AutoName;

                        uploadFile.PostedFile.SaveAs(path);

                        lblPicMsg.Visible = true;

                        lblPicMsg.Text = "文件上传成功!" + "<br>";

                        lblPicMsg.Text = lblPicMsg.Text + "文件名称：" + uploadFile.FileName + "<br>";

                        lblPicMsg.Text = lblPicMsg.Text + "文件类型：" + System.IO.Path.GetExtension(uploadFile.FileName).ToString() + "<br>";

                        lblPicMsg.Text = lblPicMsg.Text + "文件大小：" + uploadFile.FileContent.Length / 1024 + " KB" + "<br>";

                        ImageURL = @"\upImages\adv\" + AutoName;

                        //将预览图层内的图片控件显示,并将生成的缩略图地址绑定到该图片上

                        showimg.Visible = true;

                        showimg.Src = HttpContext.Current.Request.PhysicalApplicationPath + "upImages//adv//" + AutoName;

                        //清除上传图片后http数据缓冲

                        Response.Clear();

                    }

                }

            }

            else

            {

                lblPicMsg.Text = uploadFile.FileName + "文件已经存在,重新上传附件!";

            }

        }

        else

        {

            lblPicMsg.Visible = true;

            lblPicMsg.Text = "请选择上传文件 !";

        }

        ImageURL = ImageURL.Replace("\\", "/");

        return ImageURL;

    }