Posts Tagged ‘mouse

28
Mar
09

[VB.Net] Mouse Hook Class

An updated version of “Low Level Mouse Hook (Global) – Installing a Low Level Mouse Hook” from the old blog. Allows easier access to the events, as each has their own handler.

Private Class MouseHook
        Private Declare Function SetWindowsHookEx Lib "user32" Alias "SetWindowsHookExA" (ByVal idHook As Integer, ByVal lpfn As MouseProcDelegate, ByVal hmod As Integer, ByVal dwThreadId As Integer) As Integer
        Private Declare Function CallNextHookEx Lib "user32" (ByVal hHook As Integer, ByVal nCode As Integer, ByVal wParam As Integer, ByVal lParam As MSLLHOOKSTRUCT) As Integer
        Private Declare Function UnhookWindowsHookEx Lib "user32" (ByVal hHook As Integer) As Integer
        Private Delegate Function MouseProcDelegate(ByVal nCode As Integer, ByVal wParam As Integer, ByRef lParam As MSLLHOOKSTRUCT) As Integer

        Private Structure MSLLHOOKSTRUCT
            Public pt As Point
            Public mouseData As Integer
            Public flags As Integer
            Public time As Integer
            Public dwExtraInfo As Integer
        End Structure

        Public Enum Wheel_Direction
            WheelUp
            WheelDown
        End Enum

        Private Const HC_ACTION As Integer = 0
        Private Const WH_MOUSE_LL As Integer = 14
        Private Const WM_MOUSEMOVE As Integer = &H200
        Private Const WM_LBUTTONDOWN As Integer = &H201
        Private Const WM_LBUTTONUP As Integer = &H202
        Private Const WM_LBUTTONDBLCLK As Integer = &H203
        Private Const WM_RBUTTONDOWN As Integer = &H204
        Private Const WM_RBUTTONUP As Integer = &H205
        Private Const WM_RBUTTONDBLCLK As Integer = &H206
        Private Const WM_MBUTTONDOWN As Integer = &H207
        Private Const WM_MBUTTONUP As Integer = &H208
        Private Const WM_MBUTTONDBLCLK As Integer = &H209
        Private Const WM_MOUSEWHEEL As Integer = &H20A

        Private MouseHook As Integer
        Private MouseHookDelegate As MouseProcDelegate

        Public Event Mouse_Move(ByVal ptLocat As Point)
        Public Event Mouse_Left_Down(ByVal ptLocat As Point)
        Public Event Mouse_Left_Up(ByVal ptLocat As Point)
        Public Event Mouse_Left_DoubleClick(ByVal ptLocat As Point)
        Public Event Mouse_Right_Down(ByVal ptLocat As Point)
        Public Event Mouse_Right_Up(ByVal ptLocat As Point)
        Public Event Mouse_Right_DoubleClick(ByVal ptLocat As Point)
        Public Event Mouse_Middle_Down(ByVal ptLocat As Point)
        Public Event Mouse_Middle_Up(ByVal ptLocat As Point)
        Public Event Mouse_Middle_DoubleClick(ByVal ptLocat As Point)
        Public Event Mouse_Wheel(ByVal ptLocat As Point, ByVal Direction As Wheel_Direction)

        Public Sub New()
            MouseHookDelegate = New MouseProcDelegate(AddressOf MouseProc)
            MouseHook = SetWindowsHookEx(WH_MOUSE_LL, MouseHookDelegate, System.Runtime.InteropServices.Marshal.GetHINSTANCE(System.Reflection.Assembly.GetExecutingAssembly.GetModules()(0)).ToInt32, 0)
        End Sub

        Private Function MouseProc(ByVal nCode As Integer, ByVal wParam As Integer, ByRef lParam As MSLLHOOKSTRUCT) As Integer
            If (nCode = HC_ACTION) Then
                Select Case wParam
                    Case WM_MOUSEMOVE
                        RaiseEvent Mouse_Move(lParam.pt)
                    Case WM_LBUTTONDOWN
                        RaiseEvent Mouse_Left_Down(lParam.pt)
                    Case WM_LBUTTONUP
                        RaiseEvent Mouse_Left_Up(lParam.pt)
                    Case WM_LBUTTONDBLCLK
                        RaiseEvent Mouse_Left_DoubleClick(lParam.pt)
                    Case WM_RBUTTONDOWN
                        RaiseEvent Mouse_Right_Down(lParam.pt)
                    Case WM_RBUTTONUP
                        RaiseEvent Mouse_Right_Up(lParam.pt)
                    Case WM_RBUTTONDBLCLK
                        RaiseEvent Mouse_Right_DoubleClick(lParam.pt)
                    Case WM_MBUTTONDOWN
                        RaiseEvent Mouse_Middle_Down(lParam.pt)
                    Case WM_MBUTTONUP
                        RaiseEvent Mouse_Middle_Up(lParam.pt)
                    Case WM_MBUTTONDBLCLK
                        RaiseEvent Mouse_Middle_DoubleClick(lParam.pt)
                    Case WM_MOUSEWHEEL
                        Dim wDirection As Wheel_Direction
                        If lParam.mouseData < 0 Then
                            wDirection = Wheel_Direction.WheelDown
                        Else
                            wDirection = Wheel_Direction.WheelUp
                        End If
                        RaiseEvent Mouse_Wheel(lParam.pt, wDirection)
                End Select
            End If
            Return CallNextHookEx(MouseHook, nCode, wParam, lParam)
        End Function

        Protected Overrides Sub Finalize()
            UnhookWindowsHookEx(MouseHook)
            MyBase.Finalize()
        End Sub
    End Class

Usage:

   Private WithEvents mHook As New MouseHook

Since each mouse event raises its own event, you handle them like so:

    Private Sub mHook_Mouse_Left_DoubleClick(ByVal ptLocat As System.Drawing.Point) Handles mHook.Mouse_Left_DoubleClick
        Debug.WriteLine("Mouse Left Double Click At: (" & ptLocat.X & "," & ptLocat.Y & ")")
    End Sub

    Private Sub mHook_Mouse_Left_Down(ByVal ptLocat As System.Drawing.Point) Handles mHook.Mouse_Left_Down
        Debug.WriteLine("Mouse Left Down At: (" & ptLocat.X & "," & ptLocat.Y & ")")
    End Sub

    Private Sub mHook_Mouse_Left_Up(ByVal ptLocat As System.Drawing.Point) Handles mHook.Mouse_Left_Up
        Debug.WriteLine("Mouse Left Up At: (" & ptLocat.X & "," & ptLocat.Y & ")")
    End Sub

    Private Sub mHook_Mouse_Middle_DoubleClick(ByVal ptLocat As System.Drawing.Point) Handles mHook.Mouse_Middle_DoubleClick
        Debug.WriteLine("Mouse Middle Double Click At: (" & ptLocat.X & "," & ptLocat.Y & ")")
    End Sub

    Private Sub mHook_Mouse_Middle_Down(ByVal ptLocat As System.Drawing.Point) Handles mHook.Mouse_Middle_Down
        Debug.WriteLine("Mouse Middle Down At: (" & ptLocat.X & "," & ptLocat.Y & ")")
    End Sub

    Private Sub mHook_Mouse_Middle_Up(ByVal ptLocat As System.Drawing.Point) Handles mHook.Mouse_Middle_Up
        Debug.WriteLine("Mouse Middle Up At: (" & ptLocat.X & "," & ptLocat.Y & ")")
    End Sub

    Private Sub mHook_Mouse_Move(ByVal ptLocat As System.Drawing.Point) Handles mHook.Mouse_Move
        ''Will be called every time the mouse moves
    End Sub

    Private Sub mHook_Mouse_Right_DoubleClick(ByVal ptLocat As System.Drawing.Point) Handles mHook.Mouse_Right_DoubleClick
        Debug.WriteLine("Mouse Right Double Click At: (" & ptLocat.X & "," & ptLocat.Y & ")")
    End Sub

    Private Sub mHook_Mouse_Right_Down(ByVal ptLocat As System.Drawing.Point) Handles mHook.Mouse_Right_Down
        Debug.WriteLine("Mouse Right Down At: (" & ptLocat.X & "," & ptLocat.Y & ")")
    End Sub

    Private Sub mHook_Mouse_Right_Up(ByVal ptLocat As System.Drawing.Point) Handles mHook.Mouse_Right_Up
        Debug.WriteLine("Mouse Right Up At: (" & ptLocat.X & "," & ptLocat.Y & ")")
    End Sub

    Private Sub mHook_Mouse_Wheel(ByVal ptLocat As System.Drawing.Point, ByVal Direction As MouseHook.Wheel_Direction) Handles mHook.Mouse_Wheel
        Debug.WriteLine("Mouse Scroll: " & Direction.ToString & " At: (" & ptLocat.X & "," & ptLocat.Y & ")")
    End Sub

Note: To run this inside Visual Studio, you will need to go to:
Project -> [Project Name] Properties -> Debug -> Uncheck “Enable the Visual Studio hosting process”
As that intercepts the hooked messages before your program.

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