Asp.net C#上傳檔案

前台代碼:

<form id="form1" runat="server">
    <div>
        <asp:FileUpload ID="FileUpload1" runat="server" /><%--上傳檔案的控制項--%>
        <asp:Button ID="Button1" runat="server" OnClick="UploadFiles" Text="提交" /><%--提交上傳的檔案--%>
    </div>
    </form>

後台代碼

protected void UploadFiles(object sender, EventArgs e)
        {         
            try
            {
                if (HttpContext.Current.Request.Files.Count > 0)
                {
                    //System.Web.HttpPostedFile Provides access to individual files that have been uploaded by a client.
                    HttpPostedFile postedFile = HttpContext.Current.Request.Files[0];//獲得使用者提交的檔案

                    string savePath;
                    string dir = HttpContext.Current.Request.PhysicalApplicationPath;//當前應用程式的根目錄
                    savePath = dir + "Upload/DocumentFiles/";//儲存檔案的目錄,要事先添加,不會自己添加
                    string date = DateTime.Now.ToString("yyyy-M-d") + "-" + DateTime.Now.Hour.ToString() + "-" +     DateTime.Now.Minute.ToString() + "-" + DateTime.Now.Second.ToString() + "-";//根據自己需要添加
                    savePath +=date+Path.GetFileName(postedFile.FileName);
                    if (File.Exists(savePath))
                    {
                        File.Delete(savePath);//如果檔案已經存在就將已存在的檔案刪除
                    }
                    postedFile.SaveAs(savePath);//將使用者提交的檔案postedFile儲存為savePath                
                  }
            }
            catch (Exception ex)
            {
              
            }     
        }