RadCombobox SelectedIndexChanged fire when program add DataSource property

[Avelyn Teh]

Dear All,

I have 2 Radcombox
Radcombox1 will bind data in Form_Load event  And  Radcombox2 will bind when user selected item at Radcombox1

This is my code in Form_LoadRadcombox1.NullText = "- Select Name -"

Radcombox1.DisplayMember = "Name"
Radcombox1.ValueMember = "ID"
Radcombox1.DataSource = dataTable
Radcombox1.SelectedItem = vbNullString

My problem is when add DataSource to Radcombox1 (Radcombox1.DataSource = dataTable)
the Radcombox1_SelectedIndexChanged event is fire and it's also binding Radcombox2.

Please suggest how to make it Binding Radcombox2, only when user selected Item at Radcombox1.

Thanks and best regards


*question re-post from TrialUser

[Peter]

Hi Avelyn Teh,

Тhis a normal and expected behavior, because the DataSource changed the current position to 0, so the event should be fired. You can workaround this with a BeginUpdate/EndUpdate block:

Radcombox1.NullText = "- Select Name -"Radcombox1.DisplayMember = "Name"
Radcombox1.BeginUpdate()
Radcombox1.ValueMember = "ID"
Radcombox1.DataSource = dataTable
Radcombox1.SelectedItem = vbNullString
Radcombox1.EndUpdate()

I hope it helps. If you have any further questions, do not hesitate to contact me.

Best wishes,
Peter
the Telerik team

[NW7US]

In my scenario, I have a RadComboBox that contains CheckBox items.  I problematically set certain items as Checked, if data exists in a database table.  Here is a segment of code:

' now, check anything that is really checked.

 

Dim idr As Data.DataRow

Dim ids As Data.DataSet

 

Dim idt As Data.DataTable

Dim idtData As New Data.DataSet

 

Dim iParameters(0 To 0) As Data.SqlClient.SqlParameter

iParameters(0) = New Data.SqlClient.SqlParameter("@intBIDOID", CheckDBNull(CInt(BIDOID), enumObjectType.IntType))

 

ids = clsEPD_DATA.StoredGetDataset("spGetBidsSystemTypeNames", iParameters)

 

If ids.Tables(0).Rows.Count >= 1 Then

    idt = ids.Tables(0)

 

    For Each idr In idt.Rows

 

        ' "BUG" - when one and ONLY one item is check-marked, here, it causes the control to

        ' be in a state as if SelectedIndex has been changed (Telerik states this is expected).
        ' And, it stays that way, even though we set it here, and the user did NOT change anything. 


        ' This is a "bug" in our scenario, where I must determine if the USER DID THE CHANGE,

        ' not the program.

 

        Dim cboSTObject As RadComboBoxItem = cboSystemType.FindItemByValue(CheckDBNull(idr("SYSTOID"), enumObjectType.IntType))

        cboSTObject.Checked = True

        cboSTObject.Dispose()

 

    Next

 

    ids.Dispose()

 

End If

 

'------------ end of System Type checkboxed combobox ----------------------

Here is the aspx snippet:

<telerik:RadComboBox ID="cboSystemType" runat="server" Width="200px" EmptyMessage="Select the System Type (if any):"
                                                                    Height="250px" DataTextField="ST_Name" DataValueField="SYSTOID" DataSourceID="SqlDataSource5"
                                                                    TabIndex="8" CheckBoxes="True" CausesValidation="False">
                                                                </telerik:RadComboBox>
                                                                <br />
                                                                <asp:SqlDataSource ID="SqlDataSource5" runat="server" ConnectionString="<%$ ConnectionStrings:EPD_DATAConnectionString %>"
                                                                    SelectCommand="spGetBidSystemTypeNames" SelectCommandType="StoredProcedure">
                                                                </asp:SqlDataSource>

What I would like to do is create code such that when my programmatic method changes the index (which appears only to occur when only ONE items is check-marked, but never when zero, or two or more, items are check-marked by the program), that I can somehow set the SelectedIndex code to ignore it, but when the USER MAKES A CHANGE, then I pay attention to it.  Should I create an internal variable "flag" in my program to somehow watch for when I make changes pro grammatically, but clear the flag?  This seems clunky.

Any guidance would be appreciated.  Thank you.

[Stefan]

Hello Tomas,

Your question seems to concern RadComboBox for ASP.NET AJAX, while this forum is for RadComboBox for WinForms. If so, please address your question in the ASP.NET AJAX forums: http://www.telerik.com/community/forums/aspnet-ajax/combobox.aspx. 

Regards,
Stefan
the Telerik team