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How to trigger an event when the ComboBox DropDownList has null value or has no datasource bound to it?

Platform: WinForms |
Control: GridControl |
Published Date: May 13, 2016 |
Last Revised Date: May 29, 2019

If the ComboBox is neither bound to any datasource not has list items, it can be notified to the user by clicking on it. The notification message that the user wants to display can be given through TableControlCurrentCellShowingDropDown event.

Code Snippet

C#

// form()
// Trigger the required event.
gridControl1.CurrentCellShowingDropDown += gridControl1_CurrentCellShowingDropDown;
 
void gridControl1_CurrentCellShowingDropDown(object sender, GridCurrentCellShowingDropDownEventArgs e)
{
     GridComboBoxCellRenderer rend = gridControl1.CurrentCell.Renderer as GridComboBoxCellRenderer;
     ListBox list = rend.ListBoxPart;
     if(list.Items.Count==0)
     {
          MessageBox.Show("ComboBox is Empty");
     }
}

 

VB

' form()
' Trigger the required event.
Private gridControl1.CurrentCellShowingDropDown += AddressOf gridControl1_CurrentCellShowingDropDown
 
 
Private Sub gridControl1_CurrentCellShowingDropDown(ByVal sender As Object, ByVal e As GridCurrentCellShowingDropDownEventArgs)
   Dim rend As GridComboBoxCellRenderer = TryCast(gridControl1.CurrentCell.Renderer, GridComboBoxCellRenderer)
   Dim list As ListBox = rend.ListBoxPart
   If list.Items.Count=0 Then
   MessageBox.Show("ComboBox is Empty")
   End If
End Sub

 

Screenshot

Showing empty ComboBox in GridControl

 

Sample links:

C# DropDownComboBox_CS

VB DropDownComboBox_VB

 

 

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