CODEWITHSUNDEEP
wpfcomboboxlistboxmousewheelitemtemplate
droopy6
droopy6

Reputation: 301

Disable MouseWheel in editable ComboBox as ItemTemplate

I use a ComboBox as ItemTemplate inside a ListBox. My ComboBox is editable. When the user use the mouse wheel in the combobox, it change the current value. I don't want that. I want the ListBox to scroll. Is there any solution to this ? Most examples I found are based only on a readonly ComboBox. It seems that none of the solution I found works. override OnMouseWheel setting isHandled = true does not work it seems the event is handled in other places. I tried to override OnMouseWheel in the TextBox used by the ControlTemplate of my ComboBox without success.

any ideas ?

Upvotes: 9

Views: 4836

Answers (5)

Lyra
Lyra

Reputation: 465

I solved your problem with a Behavior (and the logic provided by @XamlZealot):

internal class ComboBoxIsNotScrollingItemsBehavior : Behavior<ComboBox>
{
    protected override void OnAttached()
    {
        this.AssociatedObject.PreviewMouseWheel += this.ComboBox_PreviewMouseWheel;
    }

    protected override void OnDetaching()
    {
        this.AssociatedObject.PreviewMouseWheel -= this.ComboBox_PreviewMouseWheel;
    }

    private void ComboBox_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
    {
        if (this.AssociatedObject.IsDropDownOpen == false)
        {
            e.Handled = true;

            ((FrameworkElement)this.AssociatedObject.Parent).RaiseEvent(new MouseWheelEventArgs(e.MouseDevice, e.Timestamp, e.Delta)
            {
                RoutedEvent = UIElement.MouseWheelEvent,
                Source = sender
            });
        }
    }
}

Upvotes: 4

XamlZealot
XamlZealot

Reputation: 722

I solved a similar issue once with the following approach:

WPF:

<ComboBox MouseWheel="ComboBox_MouseWheel"/>

C#:

private void ComboBox_MouseWheel(object sender, MouseWheelEventArgs e)
{
    e.Handled = true;
    MouseWheelEventArgs args = new MouseWheelEventArgs(e.MouseDevice, e.Timestamp, e.Delta);
    args.RoutedEvent = UIElement.MouseWheelEvent;
    args.Source = sender;
    parentListBox.RaiseEvent(args);
}

Upvotes: 1

droopy6
droopy6

Reputation: 301

Okay, my mistake, I put PreviewMouseWheel on a wrong UIElement of my ItemTemplate. So this is working:

private void myCombo_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
    e.Handled = true;
}

Nevertheless, the "parentListBox.RaiseEvent(args);" does not work.

Upvotes: 11

XamlZealot
XamlZealot

Reputation: 722

Try registering a class handler in your constructor:

EventManager.RegisterClassHandler(typeof(ComboBox), ComboBox.MouseWheelEvent, new RoutedEventHandler(MouseWheeled));

private void MouseWheeled(object Sender, RoutedEventArgs e)
{
    MouseWheelEventArgs mouseArgs = (MouseWheelEventArgs)e;
    e.Handled = true;
    MouseWheelEventArgs args = new MouseWheelEventArgs(mouseArgs.MouseDevice, mouseArgs.Timestamp, mouseArgs.Delta);
    args.RoutedEvent = UIElement.MouseWheelEvent;
    args.Source = Sender;
    parentListBox.RaiseEvent(args);
}

Upvotes: 1

bonCodigo
bonCodigo

Reputation: 14361

Is it correct to say our case is like, Font list box in toolbar: choosing a new font where previously selected font is still appear as the selected value, yet you could scroll vertically?

In that case can you consider a sample like this? creating a Font Box as well.

Further reference: Could you check on this MSDN article?

Upvotes: 0

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