This repository serves as an minimal, complete, verifyable example for the following WPF issue, reported on GitHub:

/dotnet/wpf/issues/5141

Having created a custom command like this:

public static RoutedUICommand ZoomIn { get; } = new RoutedUICommand("Zoom in", "ZoomIn", typeof(CustomCommands), new InputGestureCollection() { new KeyGesture(Key.OemPlus, ModifierKeys.Control), new MouseWheelGesture(WheelDirection.Down, ModifierKeys.Control) });

And having written a MouseWheelGesture like described here: https://stackoverflow.com/questions/2271342/mousebinding-the-mousewheel-to-zoom-in-wpf-and-mvvm#answer-7527482

The MouseWheelGesture.Matches() method is not getting called when the mouse wheel is rotated while the CTRL key is getting pressed.

The MouseWheelGesture.Matches() method is getting called for the CTRL key is being pressed, but not for the mouse wheel being rotated.

The MouseWheelGesture.Matches() method should be getting called when the mouse wheel being rotated with a MouseWheelEventArgs event argument.

1. Clone repository

2. Build Visual Studio 2019 .NET solution

3. Run/debug the solution

4. Activate the main window

5. Press CTRL++ to zoom in, CTRL+- to zoom out, or CTRL+0 to reset zoom to 1.0.

   => Works as expected.

6. Move the mouse cursor to the main window, hold down CTRL key and rotate the mouse wheel.

   => Nothing happens. Yet, actually, zooming should be performed, just like when using the CTRL++/CTRL+- keys