Scroll Lock key detection

If Control.IsKeyLocked(Keys.Scroll) Then
    MessageBox.Show("Scroll Lock")
Else
    MessageBox.Show("No Scroll Lock")
End If

Another solution.

If My.Computer.Keyboard.ScrollLock Then
    MessageBox.Show("Scroll Lock")
Else
    MessageBox.Show("No Scroll Lock")
End If

If Keyboard.IsKeyToggled(Key.ScrollLock) Then
    MessageBox.Show("Scroll Lock")
Else
    MessageBox.Show("No Scroll Lock")
End If

First, you have to code KeyboardUtil class as following.

Public Class KeyboardUtil
    <System.Runtime.InteropServices.DllImport("User32.dll")>
    Private Shared Function GetKeyState(keyCode As Integer) As Short
        'Keep empty
    End Function


    '''<summary>
    '''Get whether Scroll Lock key is presses or not. If pressed return true.
    '''</summary>
    Public Shared Function IsScrollLock() As Boolean
        '145 means Scroll Lock key
        If (GetKeyState(145) And &H8001) <> 0 Then
            Return True 'Scroll Lock
        Else
            Return False 'No Scroll Lock
        End If
    End Function
End Class

Next, you can use following code to detect scroll lock key.

If KeyboardUtil.IsScrollLock() Then
    Debug.WriteLine("Scroll Lock")
Else
    Debug.WriteLine("No Scroll Lock")
End If

→ Where Debug.WriteLine appear

Note: This program will only work on Windows. On Linux, it will raise System.DllNotFoundException.

Note: The basis for 0x8001 is the implementation of System.Windows.Forms.Control.IsKeyLocked. I don't understand the meaning of the high order bits.

There is no way to work on all cases. You have to choice the way case by case.

Hint

• You can call Control class and Keyboard class from both Windows Form and WPF with special configuration → how to do it
• Windows API GetKeyState is the most versatile way. But it's tiresome. You can write utility code in your original class library, it will help you.
• It is unclear for me how to determine the key on an OS other than Windows.