C# ComboBox GotFocus

Question

I have a C# ComboBox using WPF. I have code that executes when the ComboBox\'s GotFocus is activated. The issue is that the GotFoc

Answer 1

You can solve this problem with next verification:

private void myComboBox_GotFocus(object sender, RoutedEventArgs e)
{
    if (e.OriginalSource.GetType() == typeof(ComboBoxItem))
        return;
    //Your code here
}

This code will filter all focus events from items (because they use bubble routing event). But there is another problem - specific behaviour of WPF ComboBox focus: when you open drop-down list with items your ComboBox losing focus and items get. When you select some item - item losing focus and ComboBox get back. Drop-down list is like another control. You can see this by simple code:

private void myComboBox_GotFocus(object sender, RoutedEventArgs e)
{
    if (e.OriginalSource.GetType() != typeof(ComboBoxItem))
    {
        Trace.WriteLine("Got " + DateTime.Now);
    }
}

private void myComboBox_LostFocus(object sender, RoutedEventArgs e)
{
    if (e.OriginalSource.GetType() != typeof(ComboBoxItem))
    {
        Trace.WriteLine("Lost " + DateTime.Now);
    }
}

So you will get anyway atleast two focus events: when you select ComboBox and when you selecting something in it (focus will return to ComboBox).

To filter returned focus after selecting item, you can try to use DropDownOpened/DropDownClosed events with some field-flag.

So the final code with only 1 event of getting focus:

private bool returnedFocus = false;

private void myComboBox_GotFocus(object sender, RoutedEventArgs e)
{
    if (e.OriginalSource.GetType() != typeof(ComboBoxItem) && !returnedFocus)
    {
        //Your code.
    }
}

private void myComboBox_LostFocus(object sender, RoutedEventArgs e)
{
    if (e.OriginalSource.GetType() != typeof(ComboBoxItem))
    {
        ComboBox cb = (ComboBox)sender;
        returnedFocus = cb.IsDropDownOpen;
    }
}

Choose from this examples what you actually need more for your application.