C# Signature:
[DllImport("user32.dll")]
static extern bool GetKeyboardState(byte [] lpKeyState);
VB Signature:
<DllImport("user32.dll")> _
Private Shared Function GetKeyboardState(ByVal keyState() As Byte) As Boolean
End Function
Notes:
None.
Tips & Tricks:
Please add some!
Sample Code:
Imports System.Runtime.InteropServices
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Me.Text = "Caps:" & NativeMethods.CapsLockState.ToString
Me.Text &= ", Num: " & NativeMethods.NumLockState.ToString
Me.Text &= ", Scroll: " & NativeMethods.ScrollLockState.ToString
End Sub
End Class
Public Class NativeMethods
Private Shared keyState() As Byte
<DllImport("user32.dll")> _
Private Shared Function GetKeyboardState(ByVal keyState() As Byte) As Boolean
End Function
Private Shared Sub Update()
keyState = New Byte(255) {}
Dim result As Boolean = GetKeyboardState(keyState)
' Check for error:
If result = False Then
Debug.WriteLine("GetKeyBoardState error: " & Marshal.GetLastWin32Error)
Throw New Exception("GetKeyBoardState error: " & Marshal.GetLastWin32Error)
End If
End Sub
Public Enum LightState
Off
[On]
End Enum
' Example - the keyboard lights...
Public Shared ReadOnly Property CapsLockState() As LightState
Get
Update()
Dim isOn As Boolean = (keyState(Keys.CapsLock) = 1)
Return IIf(isOn, LightState.On, LightState.Off)
End Get
End Property
Public Shared ReadOnly Property NumLockState() As LightState
Get
Update()
Dim isOn As Boolean = (keyState(Keys.NumLock) = 1)
Return IIf(isOn, LightState.On, LightState.Off)
End Get
End Property
Public Shared ReadOnly Property ScrollLockState() As LightState
Get
Update()
Dim isOn As Boolean = (keyState(Keys.Scroll) = 1)
Return IIf(isOn, LightState.On, LightState.Off)
End Get
End Property
End Class
Alternative Managed API:
Do you know one? Please contribute it!
