Intercepting mouse events using a global hook. Stop an action from happening.
- by fMinkel
I'm attempting to intercept and interrupt mouse events. Lets say I wanted to disable the right mouse button down event, or even the mouse move event. I haven't been able to figure out the interrupting part.
I am using the (I assume pretty widely used) following code for Global Hooking of the mouse.
Private Structure MSLLHOOKSTRUCT
Public pt As Point
Public mouseData As Int32
Public flags As Int32
Public time As Int32
Public extra As IntPtr
End Structure
Private _mouseHook As IntPtr
Private Const WH_MOUSE_LL As Int32 = 14
Private Delegate Function MouseHookDelegate(ByVal nCode As Int32, ByVal wParam As IntPtr, ByRef lParam As MSLLHOOKSTRUCT) As Int32
<MarshalAs(UnmanagedType.FunctionPtr)> Private _mouseProc As MouseHookDelegate
Private Declare Function SetWindowsHookExW Lib "user32.dll" (ByVal idHook As Int32, ByVal HookProc As MouseHookDelegate, ByVal hInstance As IntPtr, ByVal wParam As Int32) As IntPtr
Private Declare Function UnhookWindowsHookEx Lib "user32.dll" (ByVal hook As IntPtr) As Boolean
Private Declare Function CallNextHookEx Lib "user32.dll" (ByVal idHook As Int32, ByVal nCode As Int32, ByVal wParam As IntPtr, ByRef lParam As MSLLHOOKSTRUCT) As Int32
Private Declare Function GetCurrentThreadId Lib "kernel32.dll" () As Integer
Private Declare Function GetModuleHandleW Lib "kernel32.dll" (ByVal fakezero As IntPtr) As IntPtr
Public Function HookMouse() As Boolean
Debug.Print("Mouse Hooked")
If _mouseHook = IntPtr.Zero Then
_mouseProc = New MouseHookDelegate(AddressOf MouseHookProc)
_mouseHook = SetWindowsHookExW(WH_MOUSE_LL, _mouseProc, GetModuleHandleW(IntPtr.Zero), 0)
End If
Return _mouseHook <> IntPtr.Zero
End Function
Public Sub UnHookMouse()
Debug.Print("Mouse UnHooked")
If _mouseHook = IntPtr.Zero Then Return
UnhookWindowsHookEx(_mouseHook)
_mouseHook = IntPtr.Zero
End Sub
Private Function MouseHookProc(ByVal nCode As Int32, ByVal wParam As IntPtr, ByRef lParam As MSLLHOOKSTRUCT) As Int32
'Debug.Print("Message = {0}, x={1}, y={2}", wParam.ToInt32, lParam.pt.X, lParam.pt.Y)
If wParam.ToInt32 = 513 Then
'''interrupt the left mouse button event here, but don't know what to return to do so.
End If
Return CallNextHookEx(WH_MOUSE_LL, nCode, wParam, lParam)
End Function
