How can I set the sqldatasource parameter's value?

The trick to make it work is to remove the paremeter you are trying to use before adding it. The following adapted version of your code should work:

' NOTE that there is no "@" sign when you use your parameters in the code
Parameter p = strCommandSqlDataSource2.SelectParameters["ClientID"]
strCommandSqlDataSource2.SelectParameters.Remove(p)
strCommandSqlDataSource2.SelectParameters.Add("ClientID", iClientID)

You should not use "@" sign when naming parameters in the code portion of its usage. You should use it only in the SQLCOMMAND string.

Hope it helps.

You can set your parameter's value like that :

SqlParameter parameter1 = new SqlParameter("@ClientID", SqlDbType.BigInt);
parameter1.Value = 32;
SqlDataSource2.SelectParameters.Add(parameter1);

You can workaround it by the Selecting event on the SqlDataSource, i now how frustraiting is to be restricted in this kind of controls !!!

Another alternative would be to add a HiddenField to your form, and the SqlDataSource could take its value from there.

Here's the VB version:

Dim parameter As New System.Web.UI.WebControls.Parameter("ClientID", Data.DbType.Int32)
parameter.DefaultValue = 45
sqlTicketInfo.SelectParameters.Add(parameter)

With the VB.NET version, there wasn't a way to actually set the value, so I set the default value instead. The default value gets used if the value isn't initialized, so since we can't set the value, it'll automatically use the default value anyways.

If you've used the WYSWIG editor to create your data source and you want to update the SQL parameters programmatically, then you need to do the following:

Dim strCommand = "SELECT caller_id, phone, name, email FROM callers WHERE client_id=@ClientID"

SqlDataSource2.SelectCommand = strCommand

**SqlDataSource2.SelectParameters.Clear();**

SqlDataSource2.SelectParameters.Add("@ClientID", iClientID)

I have solution for variable from GET to parameter for SelectCommand

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
   Dim p As Parameter = SQLDataSource.SelectParameters("Order_id")
   If IsNothing(p) Then
        SQLDataSource.SelectParameters.Add("Order_id", Server.HtmlEncode(Request.QueryString("Order_id")).ToString())
   End If
End Sub