Hi Lars,
I would not recommend changing the IsEditable from DropDownOpened/Closed events, since it might cause unexpected results. Here is how you can do it, though:
private void RadComboBox_DropDownOpened(object sender, EventArgs e)
{
Dispatcher.BeginInvoke(() => (sender as RadComboBox).IsEditable = true);
}
private void RadComboBox_DropDownClosed(object sender, EventArgs e)
{
Dispatcher.BeginInvoke(() => (sender as RadComboBox).IsEditable = false);
}
The problem is that when IsEditable is set, RadComboBox changes its control template, which disposes the dropdown Popup and the combo is automatically closed, because there is now a new Popup. The next click opens it, though.
All the best,
Valeri Hristov
the Telerik team