<asp:FileUpload ID="FileUpload" runat="server" />

private string upLoad() {

        string path="";

        string filepath = FileUpload.PostedFile.FileName;

        string fileName = filepath.Substring(filepath.LastIndexOf("\\") + );

        path = Server.MapPath(@"~/files/") + filepath;

        string filePath = "~/files/" + fileName;

        Response.Write(filePath);

        FileUpload.SaveAs(path);

        return filePath;

    }

protected void btnUpload_Click(object sender, EventArgs e)

{

    if (FileUpload1.HasFile)

    {

        string fileExt = System.IO.Path.GetExtension(FileUpload1.FileName);

        if (fileExt == ".jpg" || fileExt == ".gif")

        {

            try

            {

                FileUpload1.SaveAs(Server.MapPath("/ScenicImg")+"\\" + FileUpload1.FileName);

                Label1.Text = "客户端路径：" + FileUpload1.PostedFile.FileName + "<br>" +

                              "文件名：" + System.IO.Path.GetFileName(FileUpload1.FileName) + "<br>" +

                              "文件扩展名：" + System.IO.Path.GetExtension(FileUpload1.FileName) + "<br>" +

                              "文件大小：" + FileUpload1.PostedFile.ContentLength + " KB<br>" +

                              "文件MIME类型：" + FileUpload1.PostedFile.ContentType + "<br>" +

                              "保存路径：" + Server.MapPath("/ScenicImg") + "\\" + FileUpload1.FileName;

            }

            catch (Exception ex)

            {

                Label1.Text = "发生错误：" + ex.Message.ToString();

            }

        }

        else

        {

            Label1.Text = "只允许上传jpg、gif文件！";

        }

    }

    else

    {

        Label1.Text = "没有选择要上传的文件！";

    }

}