VB.Net Global keyboard hook to detect "print screen" keypress

As described...

Option Strict On
Option Explicit On

Imports System.Runtime.InteropServices

Public Class Form1

    Private Const WH_KEYBOARD_LL As Integer = 13
    Private Const WM_KEYUP As Integer = &H101
    Private Const WM_SYSKEYUP As Integer = &H105
    Private proc As LowLevelKeyboardProcDelegate = AddressOf HookCallback
    Private hookID As IntPtr

    Private Delegate Function LowLevelKeyboardProcDelegate(ByVal nCode As Integer, ByVal wParam As IntPtr, _
        ByVal lParam As IntPtr) As IntPtr

    <DllImport("user32")> _
    Private Shared Function SetWindowsHookEx(ByVal idHook As Integer, ByVal lpfn As LowLevelKeyboardProcDelegate, _
        ByVal hMod As IntPtr, ByVal dwThreadId As UInteger) As IntPtr
    End Function

    <DllImport("user32.dll")> _
    Private Shared Function UnhookWindowsHookEx(ByVal hhk As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean
    End Function

    <DllImport("user32.dll")> _
    Private Shared Function CallNextHookEx(ByVal hhk As IntPtr, ByVal nCode As Integer, ByVal wParam As IntPtr, _
        ByVal lParam As IntPtr) As IntPtr
    End Function

    <DllImport("kernel32.dll", CharSet:=CharSet.Unicode)> _
    Private Shared Function GetModuleHandle(ByVal lpModuleName As String) As IntPtr
    End Function

    Sub New()
        ' This call is required by the Windows Form Designer.
        InitializeComponent()
        ' Add any initialization after the InitializeComponent() call.
        hookID = SetHook(proc)
    End Sub

    Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As FormClosingEventArgs) Handles Me.FormClosing
        UnhookWindowsHookEx(hookID)
    End Sub

    Private Function SetHook(ByVal proc As LowLevelKeyboardProcDelegate) As IntPtr
        Using curProcess As Process = Process.GetCurrentProcess()
            Using curModule As ProcessModule = curProcess.MainModule
                Return SetWindowsHookEx(WH_KEYBOARD_LL, proc, GetModuleHandle(curModule.ModuleName), 0)
            End Using
        End Using
    End Function

    Private Function HookCallback(ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
        ' we check keyup for standard printscreen, and syskeyup incase it is alt+printscreen
        ' we aren't checking keydown, as that fires before the screenshot is taken.
        If nCode >= 0 AndAlso (wParam.ToInt32 = WM_KEYUP OrElse wParam.ToInt32 = WM_SYSKEYUP) Then
            Dim vkCode As Integer = Marshal.ReadInt32(lParam)
            If vkCode = Keys.PrintScreen Then
                Dim data As IDataObject = Clipboard.GetDataObject()
                If data.GetDataPresent(GetType(Bitmap)) Then
                    Me.BackgroundImage = DirectCast(data.GetData(GetType(Bitmap)), Bitmap)
                End If
            End If
        End If
        Return CallNextHookEx(hookID, nCode, wParam, lParam)
    End Function

End Class