Finding RadComboBox from OnSelectedIndexChanged

[Bill]

I am trying to use the Selected index of one RadComboBox help build the query to populate another RadComboBox, they are both in the <EditItemTemplate>.
I get an Object reference not set to instance of an object when I run this code just adding a RadComboBoxItem without even building the query.

Protected Sub ItemType_SelectedIndexChanged(ByVal o As Object, ByVal e As RadComboBoxSelectedIndexChangedEventArgs)
        Dim DDL As RadComboBox = TryCast(RadGrid1.FindControl("FlatFileType").Controls(0), RadComboBox)
        Dim RadComboBoxItem1 As New RadComboBoxItem("First Item")
        DDL.Items.Add(RadComboBoxItem1)
End Sub

I am not sure how to correctly access the second radcombobox to be able to populate it.
Any help is greatly appreciated.

[Shinu]

Hello Bill,

You can access the RadComboBox using NamingContainer property.

VB.NET:

Protected Sub RadComboBox1_SelectedIndexChanged1(sender As Object, e As RadComboBoxSelectedIndexChangedEventArgs)
    Dim combo As RadComboBox = TryCast(sender, RadComboBox)
    Dim item As GridEditableItem = DirectCast(combo.NamingContainer, GridEditableItem)
    Dim combo2 As RadComboBox = DirectCast(item.FindControl("FlatFileType"), RadComboBox)
    'populate 2nd combobox
End Sub

Thanks,
Shinu.

[Rakesh Gupta]

Hello Bill,

You can use below code to populate the second RadCombo on SelectedIndexChange of First RadCombo.

Let me know if any concern about this.

--
Thanks & Regards,
Rakesh Gupta

protected sub cmbCountry_SelectedIndexChanged(sender As Object, e As RadComboBoxSelectedIndexChangedEventArgs)
      {
          try
          {
              Dim cmbCountry As RadComboBox = (RadComboBox)sender;
              if (cmbCountry.SelectedValue != "")
              {
                  if (Convert.ToInt32(cmbCountry.SelectedValue) > 0)
                  {
                      Dim cmbState As RadComboBox= (RadComboBox)cmbCountry.Parent.FindControl("cmbState");

          /*
              Code to generate Data Source
          */

                      cmbState.DataSource = dataSource;
                      cmbState.DataBind();
                  }
              }
          }
          catch (Exception ex)
          {
              throw ex;
          }
      }