C# Signature:

[DllImport("user32.dll")]
static extern int CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam,
   IntPtr lParam);

// overload for use with LowLevelKeyboardProc
[DllImport("user32.dll")]
static extern int CallNextHookEx(IntPtr hhk, int nCode, WM wParam, [In]KBDLLHOOKSTRUCT lParam);

// overload for use with LowLevelMouseProc
[DllImport("user32.dll")]
static extern int CallNextHookEx(IntPtr hhk, int nCode, WM wParam, [In]MSLLHOOKSTRUCT lParam);

VB Signature:

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

' overload for use with LowLevelKeyboardProc
<DllImport("user32.dll")> _
Private Shared Function CallNextHookEx(ByVal hhk As IntPtr, ByVal nCode As Integer, ByVal wParam As WindowsMessages, <[In]()> ByVal lParam As KBDLLHOOKSTRUCT) As Integer
End Function

' overload for use with LowLevelMouseProc
<DllImport("user32.dll")> _
Private Shared Function CallNextHookEx(ByVal hhk As IntPtr, ByVal nCode As Integer, ByVal wParam As WindowsMessages, <[In]()> ByVal lParam As MSLLHOOKSTRUCT) As Integer
End Function

User-Defined Types:

WindowsMessages,KBDLLHOOKSTRUCT,MSLLHOOKSTRUCT

Notes:

hhk is ignored, so you can use IntPtr.Zero

I think the signatures are wrong. The return is IntPtr, not int. It is LRESULT in C++.

Tips & Tricks:

Please add some!

Sample Code:

Please add some!

Alternative Managed API:

The ManagedWindowsApi project (http://mwinapi.sourceforge.net) provides a Hook class and subclasses for Journal hooks, Message hooks and Low-Level hooks.

Please edit this page!

Do you have...

• helpful tips or sample code to share for using this API in managed code?
• corrections to the existing content?
• variations of the signature you want to share?
• additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).