Question

这是情况，我有一个AJAX模式弹出，我的面板里面是两（2）个连接下拉列表。一个是欧洲大陆，另一个是国家。例如，当用户选择亚洲时，各国的下拉应该包含数据。这是我的模态弹出窗口和Panel

的代码

  <asp:ModalPopupExtender ID="Modalpopupextender1" runat="server" TargetControlID="ShowPopUpButton"
        PopupControlID="pnlpopup" CancelControlID="CancelButton" BackgroundCssClass="modalBackground">
     </asp:ModalPopupExtender>

  <asp:Panel ID="pnlpopup" runat="server" BackColor="White" Height="269px" Width="400px"
        OnLoad="pnlpopup_Load">
    <tr>
                <td align="right">
                    Continent:
                </td>
                <td>
                    <asp:DropDownList ID="ContinentDownList" runat="server" 
                        onselectedindexchanged="ContinentDropDownList_SelectedIndexChanged" AutoPostBack="true">
                    </asp:DropDownList>
                </td>
            </tr>
            <tr>
                <td align="right">
                    Country:
                </td>
                <td>
                    <asp:DropDownList ID="CountryDropDownList" runat="server">
                    </asp:DropDownList>
                </td>
            </tr>
      </asp:Panel>

现在我的问题是，当我的模态弹出窗口加载时，当我选择一个大陆时，国家/地区的下拉列表不会加载。当我向我的ContinentDropDown插入AutoPostBack =“true”时，Modal Pop Up刷新并退出。我花了很长时间调试并知道如何解决这个问题。救命啊！

这是我的代码隐藏

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            LoadContinent();
            LoadCountry();
        }
    }

  public void LoadContinent()
    {
        using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString))
        {

            using (SqlCommand com = new SqlCommand("Reader.usp_LoadContinentDropDownList", con))
            {

               com.CommandType = CommandType.StoredProcedure;
                con.Open();
                try
                {

                   SqlDataReader dr = com.ExecuteReader();
                   OwnerGroupDropDownList.DataSource = dr;
                    OwnerGroupDropDownList.DataTextField = "fld_Description";
                    OwnerGroupDropDownList.DataValueField = "fld_ContinentID";

                    ContinentDropDownList.DataBind();
                }
                catch (SqlException)
                {
                    Response.Write("<script>alert('The database has encountered an error. Please try again')</script>");                    }
                catch (Exception)
                {
                    Response.Write("<script>alert('The database has encountered an error. Please try again')</script>");                    }
            }

        }
        LoadContinentDropDownList.Items.Insert(0, new ListItem("<Select Person Group>", "0")); 
    }


         public void LoadCountry()
    {
        using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString))
        {

            using (SqlCommand com = new SqlCommand("Reader.usp_LoadCountryDropDownList", con))
            {


                com.CommandType = CommandType.StoredProcedure;
                com.Parameters.Add(new SqlParameter("@fld_ContinentId", SqlDbType.Int));
                com.Parameters["@fld_ContinentId"].Value = ContinentDropDownList.SelectedValue;
                con.Open();

                try
                {

                    SqlDataReader dr = com.ExecuteReader();
                    OwnerDropDownList.DataSource = dr;
                    OwnerDropDownList.DataTextField = "fld_Description";
                    OwnerDropDownList.DataValueField = "fld_CountryID";

                    CountryDownList.DataBind();
                }
                catch (SqlException)
                {
                    Response.Write("<script>alert('The database has encountered an error. Please try again')</script>");                    }
                catch (Exception)
                {
                   Response.Write("<script>alert('The database has encountered an error. Please try again')</script>");                    }
            }
        }
         CountryDropDownList.Items.Insert(0, new ListItem("<Select Person>", "0")); 
    }

      protected void ContinentDropDownList_SelectedIndexChanged(object sender, EventArgs e)
    {
        LoadContinent();
        LoadCountry();
    }

Answer 1

您是否尝试将pnlPopup面板放在ASP.NET UpdatePanel控件中？现在，当您的下拉列表执行回发时，它将是部分回发，因为它们都在UpdatePanel内，并且它应该保持弹出式面板上的可见性。

有关创建和使用UpdatePanel的详细信息，请查看Introduction to the UpdatePanel Control。

当您将控件置于UpdatePanel之外时，AutoPostback="true"会导致完全回发，将弹出式面板“重置”为隐藏，因为这是模式弹出扩展程序的目标控件的默认状态。

Modal弹出AJAX在刷新时退出

1 个答案: