ASPX SelectParameters From aspx.vb Code Behind - asp.net

Question

I am using ASP Classic 2.0 so I know some of this code is a bit outdated but it is what I inherited. I am trying to use a variable from my backing aspx.vb page in the select query.
I have the following query (truncated)
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConflictDetection="CompareAllValues"
ConnectionString="Data Source=.;Initial Catalog=dataSQL;Persist Security Info=True;User ID=user;Password=$$$$"
ProviderName="System.Data.SqlClient"
SelectCommand="SELECT ClID, Client_Name
FROM [tblClient]
WHERE (tblClient.ClID = #ClID )"
<SelectParameters>
<asp:ControlParameter ControlID="DropDownList1" Name="ClID" PropertyName="SelectedValue"
Type="Int32" />
</SelectParameters>
</asp:SqlDataSource>
I want to replace the ControlParameter with a variable from the aspx.vb that backs this aspx page.
I know I have access to the variable because <%=ClID%> produces the correct ID but adding something .Add("ClID", DbType.Guid, clID) does not work.
I am guessing there is an easy way to do this.
If it needs to be a control I think I can bind ClID to the a form control but I cannot figure out the correct syntax for that.
Thanks,
Steve

Answer 1

First, for the <%=CLID%> remark remember that <%= is just shorthand for Response.Write(), meaning the result is only written into the final html rendered to the browser. It does not and never will insert values into aspx markup.
The .Add() code, however, is on the right track, but we still need to make two adjustments.
First, in the aspx markup use an <asp:Parameter instead of <asp:ControlParameter.
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConflictDetection="CompareAllValues"
ConnectionString="Data Source=.;Initial Catalog=dataSQL;Persist Security Info=True;User ID=user;Password=$$$$"
ProviderName="System.Data.SqlClient"
SelectCommand="SELECT ClID, Client_Name
FROM [tblClient]
WHERE tblClient.ClID = #ClID"
<SelectParameters>
<asp:Parameter Name="ClID" DbType="Int32" />
</SelectParameters>
</asp:SqlDataSource>
Then, in the aspx.vb code-behind instead of .Add() you must remember the parameter already exists. If you try to add it again you'll get an exception. Instead, you need to set the Value for the existing parameter in your code-behind:
SqlDataSource1.SelectCommand.Parameters["ClID"].Value = ClID
It's been a loooong time since I've used code like this, so you may also need to call .DataBind()