ComboBox.SelectionChangeCommitted Event

public:
 event EventHandler ^ SelectionChangeCommitted;

public event EventHandler SelectionChangeCommitted;

public event EventHandler? SelectionChangeCommitted;

member this.SelectionChangeCommitted : EventHandler 

Public Custom Event SelectionChangeCommitted As EventHandler 

The following code example uses the SelectionChangeCommitted event and the SelectionLength property to change the length of the text box depending on what the user has selected and committed.

void comboBox1_SelectionChangeCommitted( Object^ sender, EventArgs^ /*e*/ )
{
   ComboBox^ senderComboBox = dynamic_cast<ComboBox^>(sender);
   
   // Change the length of the text box depending on what the user has 
   // selected and committed using the SelectionLength property.
   if ( senderComboBox->SelectionLength > 0 )
   {
       textbox1->Width = 
           senderComboBox->SelectedItem->ToString()->Length * 
           ((int)this->textbox1->Font->SizeInPoints);
       textbox1->Text = senderComboBox->SelectedItem->ToString();				
   }
}

private void comboBox1_SelectionChangeCommitted(object sender, EventArgs e)
{

    ComboBox senderComboBox = (ComboBox) sender;
  
    // Change the length of the text box depending on what the user has 
    // selected and committed using the SelectionLength property.
    if (senderComboBox.SelectionLength > 0)
    {
        textbox1.Width = 
            senderComboBox.SelectedItem.ToString().Length *
            ((int) this.textbox1.Font.SizeInPoints);
        textbox1.Text = senderComboBox.SelectedItem.ToString();
    }
}

Private Sub comboBox1_SelectionChangeCommitted(ByVal sender _
As Object, ByVal e As EventArgs) _
Handles comboBox1.SelectionChangeCommitted

    Dim senderComboBox As ComboBox = CType(sender, ComboBox)

    ' Change the length of the text box depending on what the user has 
    ' selected and committed using the SelectionLength property.
    If (senderComboBox.SelectionLength > 0) Then
        textbox1.Width = _
            senderComboBox.SelectedItem.ToString().Length() * _
            CType(Me.textbox1.Font.SizeInPoints, Integer)
        textbox1.Text = senderComboBox.SelectedItem.ToString()
    End If
End Sub

The SelectionChangeCommitted event is raised only when the user changes the combo box selection, and you can create a handler for this event to provide special handling for the ComboBox when the user changes the selected item in the list. However, depending on how the ComboBox is configured, and how the user changes the selected item, the SelectionChangeCommitted event may not be raised. Alternatively, you can handle the SelectedIndexChanged, but note that this event occurs whether the index is changed programmatically or by the user.

For more information about handling events, see Handling and Raising Events.