C# related Telerik ComboBoxes issue on Page_Load

Question

I am C# noobie, I have inherited big C# project and I have to do a litlle modifications.

First let me past the code:

protected void Page_Load(object sender, EventArgs e)
{
    // Loading rcb1
    this.dsX.SelectParameters["parameter1"].DefaultValue = XXX.XXX.ToString();
    this.dsX.SelectParameters["parameter2"].DefaultValue = this.XXX.ToString();

    if ( !IsPostBack )
    {
        Control c = sender as Control;
        RadComboBox rcb1 = c.Parent.FindControl("rcb1") as RadComboBox;

        // Loading rcb2
        this.dsY.SelectParameters["parameter1"].DefaultValue = XXX.XXX.ToString();
        this.dsY.SelectParameters["parameter1"].DefaultValue = this.XXX.ToString();

        // Value of first option from rcb1
        this.dsY.SelectParameters["rcb1_value"].DefaultValue = rcb1.SelectedValue.ToString();
    }
}




protected void rcb1_SelectedIndexChanged(object o, RadComboBoxSelectedIndexChangedEventArgs e)
{
    if (e.Value != "")
    {
        Control c = o as Control;
        RadComboBox rcb1 = c.Parent.FindControl("rcb1") as RadComboBox;
        RadComboBox rcb2 = c.Parent.FindControl("rcb2") as RadComboBox;

        this.dsUsers.SelectParameters["parameter1"].DefaultValue = XXX.XXX.ToString();            
        this.dsUsers.SelectParameters["parameter2"].DefaultValue = this.XXX.ToString();
        this.dsUsers.SelectParameters["parameter3"].DefaultValue = e.Value.ToString();
    }
}


<tr>
    <td align="left" height="22px">
        LABEL
    </td>
    <td align="left" height="22px">
        <telerik:RadComboBox ID="rcb1" runat="server" DataSourceID="dsX" DataTextField="PONotificationName"
            DataValueField="ID" Skin="Vista" meta:resourcekey="xxResource1"
            OnSelectedIndexChanged="rcb1_SelectedIndexChanged" AutoPostBack="true">
        </telerik:RadComboBox>
        <asp:SqlDataSource ID="dsX" runat="server" ConnectionString="<%$ connectionStrings:XXX %>"
            SelectCommand="XXX" SelectCommandType="StoredProcedure">
            <SelectParameters>
                <asp:Parameter Name="parameter1" Type="Int32" />
                <asp:Parameter Name="parameter2" Type="Int32" />
            </SelectParameters>
        </asp:SqlDataSource>
    </td>
</tr>
<tr>
    <td align="left" height="22px">
        LABEL 2
    </td>
    <td align="left" height="22px">
        <telerik:RadComboBox ID="rcb2" runat="server" DataSourceID="dsY" DataTextField="Name"
            DataValueField="ID" Skin="Vista" meta:resourcekey="xxResource2">
        </telerik:RadComboBox>
        <asp:SqlDataSource ID="dsY" runat="server" ConnectionString="<%$ connectionStrings:XXX %>"
            SelectCommand="XXX2" SelectCommandType="StoredProcedure">
            <SelectParameters>
                <asp:Parameter Name="parameter1" Type="Int32" />
                <asp:Parameter Name="parameter2" Type="Int32" />
                <asp:Parameter Name="parameter3" Type="Int32" />
            </SelectParameters>
        </asp:SqlDataSource>
    </td>
</tr>

My problem is those comboBoxes. The code is working fine, but the problem is before user do any action the second comboBox (rcb2) stays blank.

I have to load second combobox(rcb2) with the data from first combobox(rcb1) using stored procedure.

I have tried .SelectedValue. Item[index].value and others it returns null.

Maybe the problem is that first ComboBox doesnt have definition for selected item?

Can anybody help me solve this?

I can either add new blank item to rcb1 at the top. But I had problems with that too.

Answer 1

Solved my problem with emptymessage... gosh took me whole day!

<telerik:RadComboBox ID="rcb1" runat="server" DataSourceID="dsX" DataTextField="PONotificationName"
            DataValueField="ID" Skin="Vista" meta:resourcekey="xxResource1"
            OnSelectedIndexChanged="rcb1_SelectedIndexChanged" AutoPostBack="true" emptymessage="Select Value...">
</telerik:RadComboBox>