Question

我有两个与两个下拉列表相关的SqlDataSource。 PopulateDLL（）方法允许我使用城镇填充第一个下拉列表并过滤第二个下拉列表，其中包含与该城镇相关的街道名称，但是一些街道名称也有建筑物名称（即市政厅，主街道），我是什么尝试做的是包含具有适当街道名称的建筑物名称。我研究了这个并得到了代码

        dt.Columns.Add("StreetName + BuildingName");
        ddl_FilteredLocation.DataTextField = "BuildingName";
        //ddl_FilteredLocation.DataValueField = "";
        ddl_FilteredLocation.DataBind();

然而它仍然只调用街道名称，我尝试了不同的变化，有时只会出现建筑物名称，但没有街道名称，任何帮助都会很棒，谢谢！

<%-- DS for DDL Location --%>
 <asp:SqlDataSource ID="ds_Location" EnableCaching="false" DataSourceMode="DataSet" runat="server" >

    ConnectionString="<%$ ConnectionStrings:DataTown %>"

    SelectCommand="SELECT DISTINCT Town FROM [DataTown].[dbo].[DT] Order By Town">
  <asp:SqlDataSource>

<%-- DS for DDL Street Name, filterExpression is used so that when a user selects a town from ddl_Location the streets for that town are filtered --%>

<asp:SqlDataSource ID="ds_StreetName" EnableCaching="true" DataSourceMode="DataSet" runat="server" ConnectionString="<%$ ConnectionStrings:DataTown %>"

        SelectCommand="SELECT Town, BuildingName, StreetName FROM [DataTown].[dbo].[DT] Order By StreetName" FilterExpression="Town = '{0}'">


        <FilterParameters>
           <asp:ControlParameter Name="Town" ControlID="fmv_AccidentHSUData$ddl_Location" PropertyName="SelectedValue" />
        </FilterParameters>
</asp:SqlDataSource>



   <asp:DropDownList ID="ddl_Location" AutoPostBack="true" Width="100%" runat="server"></asp:DropDownList>

   <asp:DropDownList ID="ddl_FilteredLocation" DataSourceID="ds_StreetName" DataTextField="StreetName" DataValueField="StreetName" AutoPostBack="true" Width="100%" runat="server">


protected void PopulateDDL()
    {
        DropDownList ddl_Location = (DropDownList)fmv_DataTown.FindControl("ddl_Location");
        DropDownList ddl_FilteredLocation = (DropDownList)fmv_DataTown.FindControl("ddl_FilteredLocation");
        ddl_Location.Items.Clear();
        DataView view = (DataView)ds_Location.Select(DataSourceSelectArguments.Empty);
        DataTable dt = view.ToTable();
        dt.Columns.Add("StreetName + BuildingName");
        ddl_FilteredLocation.DataTextField = "BuildingName";
        //ddl_FilteredLocation.DataValueField = "";
        ddl_FilteredLocation.DataBind();

        foreach (DataRow row in dt.Rows)
        {

            string Town = row["Town"].ToString();
            //string StreetName = row["StreetName"].ToString();
            string FullText = "";
            if (Town.Length > 0)
            {
                FullText = Town;
            }
            else
            {

            }
            ddl_Location.Items.Add(new ListItem(FullText, FullText));
        }
    }

Answer 1

下面的代码是我遇到的问题的解决方案

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

protected void PopulateDDL()
    {
        DropDownList ddl_Location = (DropDownList)fmv_DataTown.FindControl("ddl_Location");
        DropDownList ddl_FilteredLocation = (DropDownList)fmv_DataTown.FindControl("ddl_FilteredLocation");
        ddl_Location.Items.Clear();
        DataView view = (DataView)ds_Location.Select(DataSourceSelectArguments.Empty);
        DataTable dt = view.ToTable();

        foreach (DataRow row in dt.Rows)
        {

            string Town = row["Town"].ToString();
            string FullText = "";
            if (Town.Length > 0)
            {
                FullText = Town;
            }
            else
            {

            }
            ddl_Location.Items.Add(new ListItem(FullText, FullText));
        }
    }

尝试在DropDownList中组合两个字段

1 个答案: