Trying to write a better WndProc Handling

Question

I'm trying to write a better (I think is better) and reusable WndProc procedure, but the code below does not work because when I add more arguments to the sub firm it says that the sub does not accept that amount of arguments, of course that is reasonable.

But I know that this trick can be done because I've seen this same wndproc sub with a lot of custom arguments time ago in some thirdparty classes which I don't remember where I've seen neither I don't remember how them did the trick.

Then, someone could help me to fix this code and to improve it if it has something wrong?

Also, there is something to remark about the performance doing a modification like this? really I don't know if something like this can affect the performance in some way.

''' <summary>
''' Windows Message Identifiers.
''' </summary>
Private Enum Messages As Integer
    ''' <summary>
    ''' Message is sent when the user chooses a command from the system menu,
    ''' or when the user chooses the "maximize", "minimize", "restore", or "close" buttons.
    ''' </summary>
    WM_SYSCOMMAND = &H112
End Enum

''' <summary>
''' Intercepts Windows messages for this Window.
''' </summary>
''' <param name="MsgInt32">
''' Message Identifier as Integer.
''' </param>
''' <param name="MsgWin32">
''' Message Identifier as Win32Hex format.
''' </param>
''' <param name="MsgHex">
''' Message Identifier as Hexadecimal format.
''' </param>
''' <param name="HWnd">
''' Window Handle.
''' </param>
''' <param name="LParam">
''' LParan message argument.
''' </param>
''' <param name="WParam">
''' WParam message argument.
''' </param>
''' <param name="Result">
''' Specifies the value that is returned to window in response to handling the message.
''' </param>
Protected Overrides Sub WndProc(ByRef m as Message,
                                ByRef MsgInt32 As Integer
                                ByRef MsgWin32 As String,
                                ByRef MsgHex As String,
                                ByRef HWnd As IntPtr,
                                ByRef LParam As IntPtr,
                                ByRef WParam As IntPtr,
                                ByRef Result As IntPtr)

    Select Case MsgInt32

        Case Messages.WM_SYSCOMMAND

            MsgBox(MsgWin32)
            MsgBox(LParam)
            MsgBox(WParam)

    End Select

    ' Return control to base message handler.
    MyBase.WndProc(m, CInt(m.Msg), "&H" & Hex(m.Msg), Hex(m.Msg), m.HWnd, m.LParam, m.WParam, m.Result)

End Sub

UPDATE:

I've found one of the original codes that I will to reproduce to manage messages easier.

Public Declare Function CallWindowProc Lib "user32.dll" Alias "CallWindowProcA" (ByVal _
    lpPrevWndFunc As Long, ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam _
    As Long, ByVal lParam As Long) As Long

Public Delegate Function ipWindowProc(ByVal hwnd As Integer, ByVal uMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer

Dim ip As ipWindowProc = AddressOf Me.WindowProc

' The following function acts as Form1's window procedure to process messages.
Public Function WindowProc(ByVal hwnd As Integer, ByVal uMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer
    Dim bTopMost As Boolean = Me.TopMost
    Dim hMenu As Integer = 0
    Dim iRet As Integer = 0
    Dim mii As MENUITEMINFO
Select Case uMsg
    Case WM_INITMENU
        hMenu = GetSystemMenu(hwnd, 0)
        mii.cbSize = Len(mii)
        mii.fMask = MIIM_STATE
        If bTopMost = True Then
            mii.fState = MFS_ENABLED Or MFS_CHECKED
        Else
            mii.fState = MFS_ENABLED Or 0
        End If
        iRet = SetMenuItemInfo(hMenu, 1, 0, mii)
        WindowProc = 0
    Case WM_SYSCOMMAND
        If wParam = 1 Then
            mii.cbSize = Len(mii)
            mii.fMask = MIIM_STATE
            If bTopMost = True Then
                mii.fState = MFS_ENABLED Or 0
                iRet = SetMenuItemInfo(hMenu, 1, 0, mii)
                Me.TopMost = False
            Else
                mii.fState = MFS_ENABLED Or MFS_CHECKED
                iRet = SetMenuItemInfo(hMenu, 1, 0, mii)
                Me.TopMost = True
            End If
            WindowProc = 0
        Else
            WindowProc = CallWindowProc(ioProc, hwnd, uMsg, wParam, lParam)
        End If
    Case Else
        WindowProc = CallWindowProc(ioProc, hwnd, uMsg, wParam, lParam)
End Select
End Function

UPDATE 2

Well, I have translated this from the code above, now what I need to add to make it working as a wndproc replacement like in the code above?

public class form1

<System.Runtime.InteropServices.
DllImport("user32.dll")>
Private Shared Function CallWindowProc(
        ByVal lpPrevWndFunc As WndProcDelegate,
        ByVal hWnd As IntPtr,
        ByVal Msg As UInteger,
        ByVal wParam As IntPtr,
        ByVal lParam As IntPtr
) As IntPtr
End Function

Delegate Function WndProcDelegate(
         ByVal hWnd As IntPtr,
         ByVal msg As UInteger,
         ByVal wParam As IntPtr,
         ByVal lParam As IntPtr
) As IntPtr

''' <summary>
''' Process Windows messages.
''' This function acts as wndproc.
''' </summary>
Public Function WindowProc(ByVal hwnd As IntPtr,
                           ByVal uMsg As UInteger,
                           ByVal wParam As IntPtr,
                           ByVal lParam As IntPtr) As Integer

    Select Case uMsg

        Case &H112

            MsgBox("Message intercepted!")

    End Select

End Function

End class

Answer 1

Why?...why would you do this?

You're just opening yourself up to making mistakes. An old school VB6 program would use this type of API because of the simple fact that the language didn't provide a built-in way of doing it. If you needed to go low level then that was one way of doing it.

VB.Net gives this to you for free, though, by allowing you to override WndProc().

That API doesn't make managing messages any easier. All those "extra" parameters you're trying to access by using this API are already there in the Message parameter called "m" in the canned WndProc() procedure:

Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
    MyBase.WndProc(m)
End Sub

Take a look at the Properties listed for Message:

Those values are all there. You can make a nice Select Case Statement using m.Msg:

Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
    Select Case m.Msg
        Case WM_LBUTTONDOWN

        Case WM_RBUTTONDOWN

    End Select
    MyBase.WndProc(m)
End Sub

...and you can access the other params the same way. You can set the Result() property to change the way the message is handled. You can even change the message, etc. If you want a friendly String version of the message then use m.ToString().

It's all there my friend...using the API doesn't give you anything you don't already have, it just creates more work on your part.