ASP.NET的DropDownList發佈「」

Question

我使用ASP.NET VB中形成3.5版

我有一個裝滿數據從數據庫與國家

爲代碼列表的下拉列表下拉列表是

  <label class="ob_label"> 
      <asp:DropDownList ID="lstCountry" runat="server" CssClass="ob_forminput"> 
      </asp:DropDownList> 
     Country*</label> 

而且該列表是

Dim selectSQL As String = "exec dbo.*******************" 

    ' Define the ADO.NET objects. 
    Dim con As New SqlConnection(connectionString) 
    Dim cmd As New SqlCommand(selectSQL, con) 
    Dim reader As SqlDataReader 

    ' Try to open database and read information. 
    Try 
     con.Open() 
     reader = cmd.ExecuteReader() 

     ' For each item, add the author name to the displayed 
     ' list box text, and store the unique ID in the Value property. 

     Do While reader.Read() 
      Dim newItem As New ListItem() 
      newItem.Text = reader("AllSites_Countries_Name") 
      newItem.Value = reader("AllSites_Countries_Id") 
      CType(LoginViewCart.FindControl("lstCountry"), DropDownList).Items.Add(newItem) 
     Loop 
     reader.Close() 

     CType(LoginViewCart.FindControl("lstCountry"), DropDownList).SelectedValue = 182 

    Catch Err As Exception 
     Response.Redirect("~/error-on-page/") 

     MailSender.SendMailMessage("*********************", "", "", OrangeBoxSiteId.SiteName & " Error Catcher", "<p>Error in sub FillCountry</p><p>Error on page:" & HttpContext.Current.Request.Url.AbsoluteUri & "</p><p>Error details: " & Err.Message & "</p>") 
     Response.Redirect("~/error-on-page/") 
    Finally 
     con.Close() 
    End Try 

當表單提交的代碼發生錯誤，說明字符串「」不能轉換爲數據類型整數。出於某種原因，下拉列表會張貼「」而不是所選國家/地區的值。

Answer 1

2我能想到的東西。

1）你確定SQL返回的值是182嗎？

2）您是否正在重建回傳下拉列表？因爲它是動態的，否則它將不知道你選擇了哪個值。