Detect if Modifier Key is Pressed in KeyRoutedEventArgs Event

Question

I have the following code:

public void tbSpeed_KeyDown(object sender, KeyRoutedEventArgs e)
{
    e.Handled = !((e.Key >= 48 && e.Key <= 57) || (e.Key >= 96 && e.Key <= 105) || (e.Key == 109) || (e.Key == 189));
}

Is there any way to detect if any modifier key like shift is being pressed ?

Billbillabong

Answer 1

Use GetKeyState. e.g.

var state = CoreWindow.GetForCurrentThread().GetKeyState(VirtualKey.Shift);
return (state & CoreVirtualKeyStates.Down) == CoreVirtualKeyStates.Down;

Note: For Alt, you would use VirtualKey.Menu.

Laoighis

Answer 2

For Win10 UWP I noticed that the CTRL and SHIFT keys were set at Locked state. So I did the following:

var shiftState = CoreWindow.GetForCurrentThread().GetKeyState(VirtualKey.Shift);
var ctrlState = CoreWindow.GetForCurrentThread().GetKeyState(VirtualKey.Control);

var isShiftDown = shiftState != CoreVirtualKeyStates.None;
var isCtrlDown = ctrlState != CoreVirtualKeyStates.None;

Quade

It is actually even better to use the HasFlag method - CoreWindow.GetForCurrentThread().GetKeyState(VirtualKey.Shift).HasFlag( CoreVirtualKeyStates.Down ) - because this way you avoid the situation where the key is only locked but not actually pressed. – Housewifely

Answer 3

For those looking for WinUI 3-specific approach (CoreWindow is not available there), use the InputKeyboardSource.GetKeyStateForCurrentThread method:

var state = InputKeyboardSource.GetKeyStateForCurrentThread(Windows.System.VirtualKey.Shift);
var isShiftPressed = state.HasFlag(Windows.UI.Core.CoreVirtualKeyStates.Down);

Housewifely

Answer 4

You can try the following code

CoreVirtualKeyStates controlKeyState = Window.Current.CoreWindow.GetKeyState(VirtualKey.Control);
var  ctrl = (controlKeyState & CoreVirtualKeyStates.Down) == CoreVirtualKeyStates.Down;

CoreVirtualKeyStates shiftKeyState = Window.Current.CoreWindow.GetKeyState(VirtualKey.Shift);
var shift = (shiftKeyState & CoreVirtualKeyStates.Down) == CoreVirtualKeyStates.Down;

Skerry

Answer 5

Bitwise AND the Modifiers property of Keyboard with Shift Key -

bool isShiftKeyPressed = (Keyboard.Modifiers & ModifierKeys.Shift)
                         == ModifierKeys.Shift;

Try this too-

bool isShiftKeyPressed = (ModifierKeys & Keys.Shift) == Keys.Shift;

OR

Control.ModifierKeys == Keys.Shift

Bergman

I hate comments that are so vague as to be misleading. What @Billbillabong should have said is, that code is perfectly fine and dandy, except the Keyboard class is not available under UWP. – Pseudohemophilia