Прервать Mousehook, избавиться и создать новый Mousehook?

Question

Я использую Mousehook (я пробовал 2 разных крючка), но он вылетает. Я думаю, что причина в том, что мы делаем щелчок мышью во время незавершенных расчетов. Я не знаю точной причины, но через некоторое время она перестает работать.

Поэтому я попробовал другое, каждый раз, когда я заканчивал вычисление, я удалял (старый) Mousehook и создавал новый.

Это отлично работало и делает свою работу... но на этот раз приложение через некоторое время вылетает с ошибками "сборка мусора" и "вызов". Я думаю, что причина в том, что я не могу избавиться от крючка, как я? Но возможно ли что-то подобное?

#Region " Option Statements "

Option Strict On
Option Explicit On
Option Infer Off

#End Region

#Region " Imports "

Imports System.ComponentModel
Imports System.Reflection
Imports System.Runtime.InteropServices
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Diagnostics


#End Region

#Region " MouseHook "

''' <summary>
''' A low level mouse hook that processes mouse input events.
''' </summary>
Friend NotInheritable Class MouseHook : Implements IDisposable

#Region " P/Invoke "

Protected NotInheritable Class NativeMethods

#Region " Methods "

    <DllImport("user32.dll", CallingConvention:=CallingConvention.StdCall, CharSet:=CharSet.Auto)>
    Public Shared Function CallNextHookEx(
           ByVal idHook As IntPtr,
           ByVal nCode As Integer,
           ByVal wParam As IntPtr,
           ByVal lParam As IntPtr
    ) As IntPtr
    End Function

    <DllImport("user32.dll", CallingConvention:=CallingConvention.StdCall, CharSet:=CharSet.Auto)>
    Public Shared Function SetWindowsHookEx(
           ByVal idHook As HookType,
           ByVal lpfn As LowLevelMouseProcDelegate,
           ByVal hInstance As IntPtr,
           ByVal threadId As UInteger
    ) As IntPtr
    End Function

    <DllImport("user32.dll", CallingConvention:=CallingConvention.StdCall, CharSet:=CharSet.Auto)>
    Public Shared Function UnhookWindowsHookEx(
           ByVal idHook As IntPtr
    ) As Boolean
    End Function

    <DllImport("user32.dll", CharSet:=CharSet.Auto)>
    Public Shared Function GetDoubleClickTime() As Integer
    End Function


#End Region

#Region " Enumerations "

    Public Enum WindowsMessages As UInteger

        WM_MOUSEMOVE = &H200UI
        WM_LBUTTONDOWN = &H201UI
        WM_LBUTTONUP = &H202UI
        WM_RBUTTONDOWN = &H204UI
        WM_RBUTTONUP = &H205UI
        WM_MBUTTONDOWN = &H207UI
        WM_MBUTTONUP = &H208UI
        WM_MOUSEWHEEL = &H20AUI

    End Enum

    Public Enum HookType As UInteger

        ' **************************************
        ' This enumeration is partially defined.
        ' **************************************

        ''' <summary>
        ''' Installs a hook procedure that monitors low-level mouse input events. 
        ''' For more information, see the LowLevelMouseProc hook procedure.
        ''' </summary>
        WH_MOUSE_LL = 14UI

    End Enum

    <Flags()>
    Public Enum MsllHookStructFlags As Integer

        ''' <summary>
        ''' Test the event-injected (from any process) flag.
        ''' </summary>
        LLMHF_INJECTED = 1I

        ''' <summary>
        ''' Test the event-injected (from a process running at lower integrity level) flag.
        ''' </summary>
        LLMHF_LOWER_IL_INJECTED = 2I

    End Enum

#End Region

#Region " Structures "

    ''' <summary>
    ''' The POINT structure defines the x- and y- coordinates of a point.
    ''' MSDN Documentation: http://msdn.microsoft.com/en-us/library/windows/desktop/dd162805%28v=vs.85%29.aspx
    ''' </summary>
    <StructLayout(LayoutKind.Sequential)>
    Public Structure Point

        Public X As Integer
        Public Y As Integer

    End Structure

    Public Structure MsllHookStruct

        ''' <summary>
        ''' The ptThe x- and y-coordinates of the cursor, in screen coordinates.
        ''' </summary>
        Public Pt As NativeMethods.Point

        ''' <summary>
        ''' If the message is 'WM_MOUSEWHEEL', the high-order word of this member is the wheel delta. 
        ''' The low-order word is reserved. 
        ''' A positive value indicates that the wheel was rotated forward, away from the user; 
        ''' a negative value indicates that the wheel was rotated backward, toward the user. 
        ''' One wheel click is defined as 'WHEEL_DELTA', which is '120'.
        ''' </summary>
        Public MouseData As Integer

        ''' <summary>
        ''' The event-injected flag.
        ''' </summary>
        Public Flags As MsllHookStructFlags

        ''' <summary>
        ''' The time stamp for this message. 
        ''' </summary>
        Public Time As UInteger

        ''' <summary>
        ''' Additional information associated with the message.
        ''' </summary>
        Public DwExtraInfo As IntPtr

    End Structure

#End Region

#Region " Delegates "

    ''' <summary>
    ''' Delegate LowLevelMouseProc
    ''' MSDN Documentation: http://msdn.microsoft.com/en-us/library/windows/desktop/ms644986%28v=vs.85%29.aspx
    ''' </summary>
    ''' <returns>
    ''' If nCode is less than zero, the hook procedure must return the value returned by CallNextHookEx.
    ''' If nCode is greater than or equal to zero, and the hook procedure did not process the message, 
    ''' it is highly recommended that you call CallNextHookEx and return the value it returns; 
    ''' otherwise, other applications that have installed WH_MOUSE_LL hooks will not receive hook notifications 
    ''' and may behave incorrectly as a result.
    ''' If the hook procedure processed the message, 
    ''' it may return a nonzero value to prevent the system from passing the message to the rest of the hook chain or the target window procedure. 
    ''' </returns>
    Public Delegate Function LowLevelMouseProcDelegate(
            ByVal nCode As Integer,
            ByVal wParam As NativeMethods.WindowsMessages,
            ByVal lParam As IntPtr
    ) As Integer

#End Region

End Class

#End Region

#Region " Properties "

''' <summary>
''' Handle to the hook procedure.
''' </summary>
Private Property MouseHook As IntPtr

''' <summary>
''' The mouse hook delegate.
''' </summary>
Private Property MouseHookDelegate As NativeMethods.LowLevelMouseProcDelegate

''' <summary>
''' Determines whether the Hook is installed.
''' </summary>
Public Property IsInstalled As Boolean

''' <summary>
''' Determines whether the Hook is enabled.
''' </summary>
Public Property IsEnabled As Boolean = False

''' <summary>
''' ** ONLY FOR TESTING PURPOSES **
''' Gets or sets a value indicating whether to suppress the last MouseUp event of 
''' the specified clicked button when a double-click fires.
''' 
''' If this value is set to <c>true</c>, the application will send the events in this order for a Double-Click:
''' MouseDown, MouseUp, MouseDown, MouseDoubleClick
''' 
''' If this value is set to <c>false</c>, the application will send the events in this order for a Double-Click:
''' MouseDown, MouseUp, MouseDown, MouseUp, MouseDoubleClick
''' 
''' </summary>
''' <value><c>true</c> if MouseUp event is suppressed; otherwise <c>false</c>.</value>
Public Property SuppressMouseUpEventWhenDoubleClick As Boolean = False

''' <summary>
''' Gets or sets the screen's working area.
''' The events fired by this <see cref="MouseHook"/> instance will be restricted to the bounds of the specified rectangle.
''' </summary>
''' <value>The screen's working area.</value>
Public Property WorkingArea As Rectangle
    Get
        Return Me.workingarea1
    End Get
    Set(ByVal value As Rectangle)
        Me.workingarea1 = value
        'MsgBox(WorkingArea.Bottom.ToString)
    End Set
End Property

''' <summary>
''' The screen's working area
''' </summary>
Private workingarea1 As Rectangle = SystemInformation.VirtualScreen

#End Region

#Region " Enumerations "

''' <summary>
''' Indicates the whell direction of the mouse.
''' </summary>
Public Enum WheelDirection As Integer

    ''' <summary>
    ''' The wheel is moved up.
    ''' </summary>
    WheelUp = 1I

    ''' <summary>
    ''' The wheel is moved down.
    ''' </summary>
    WheelDown = 2I

End Enum

#End Region

#Region " Events "

Public Event MouseMove(ByVal sender As Object,
                       ByVal mouseLocation As Point)

Public Event MouseLeftDown(ByVal sender As Object,
                           ByVal mouseLocation As Point)

Public Event MouseLeftUp(ByVal sender As Object,
                         ByVal mouseLocation As Point)

Public Event MouseLeftDoubleClick(ByVal sender As Object,
                                  ByVal mouseLocation As Point)

Public Event MouseRightDown(ByVal sender As Object,
                            ByVal mouseLocation As Point)

Public Event MouseRightUp(ByVal sender As Object,
                          ByVal mouseLocation As Point)

Public Event MouseRightDoubleClick(ByVal sender As Object,
                                   ByVal mouseLocation As Point)

Public Event MouseMiddleDown(ByVal sender As Object,
                             ByVal mouseLocation As Point)

Public Event MouseMiddleUp(ByVal sender As Object,
                           ByVal mouseLocation As Point)

Public Event MouseMiddleDoubleClick(ByVal sender As Object,
                                    ByVal mouseLocation As Point)

Public Event MouseWheel(ByVal sender As Object,
                        ByVal mouseLocation As Point,
                        ByVal wheelDirection As WheelDirection)

#End Region

#Region " Exceptions "

''' <summary>
''' Exception that is thrown when trying to enable or uninstall a mouse hook that is not installed.
''' </summary>
<Serializable()>
Friend NotInheritable Class MouseHookNotInstalledException : Inherits Exception

    Friend Sub New()
        MyBase.New("MouseHook is not installed.")
    End Sub

    Friend Sub New(ByVal message As String)
        MyBase.New(message)
    End Sub

    Friend Sub New(ByVal message As String, ByVal inner As Exception)
        MyBase.New(message, inner)
    End Sub

End Class

''' <summary>
''' Exception that is thrown when trying to disable a mouse hook that is not enabled.
''' </summary>
<Serializable()>
Friend NotInheritable Class MouseHookNotEnabledException : Inherits Exception

    Friend Sub New()
        MyBase.New("MouseHook is not enabled.")
    End Sub

    Friend Sub New(ByVal message As String)
        MyBase.New(message)
    End Sub

    Friend Sub New(ByVal message As String, ByVal inner As Exception)
        MyBase.New(message, inner)
    End Sub

End Class

''' <summary>
''' Exception that is thrown when trying to enable a mouse hook that is already enabled.
''' </summary>
<Serializable()>
Friend NotInheritable Class MouseHookEnabledException : Inherits Exception

    Friend Sub New()
        MyBase.New("MouseHook is already enabled.")
    End Sub

    Friend Sub New(ByVal message As String)
        MyBase.New(message)
    End Sub

    Friend Sub New(ByVal message As String, ByVal inner As Exception)
        MyBase.New(message, inner)
    End Sub

End Class

#End Region

#Region " Constructors "

'Private Sub New()
'End Sub

''' <summary>
''' Initializes a new instance of the <see cref="MouseHook"/> class.
''' </summary>
''' <param name="Install">
''' If set to <c>true</c>, the Hook starts initialized for this <see cref="MouseHook"/> instance.
''' </param>
Public Sub New(Optional ByVal install As Boolean = False)

    If install Then
        Me.Install()
    End If

End Sub

#End Region
<DllImport("kernel32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
Public Shared Function GetModuleHandle(ByVal lpModuleName As String) As IntPtr
End Function
#Region " Public Methods "

''' <summary>
''' Installs the Mouse Hook, then start processing messages to fire events.
''' </summary>
Public Sub Install()

    If Me.IsVisualStudioHostingProcessEnabled() Then
        Throw New Exception("Visual Studio Hosting Process should be deactivated.")
        Exit Sub
    End If

    Me.MouseHookDelegate = New NativeMethods.LowLevelMouseProcDelegate(AddressOf LowLevelMouseProc)

    Try
        Me.MouseHook = NativeMethods.SetWindowsHookEx(NativeMethods.HookType.WH_MOUSE_LL,
                                                      Me.MouseHookDelegate,
                                                      Getmodulehandle(Process.GetCurrentProcess().MainModule.ModuleName), 0)

        Me.IsInstalled = True

    Catch ex As Exception
        Throw

    End Try

End Sub

''' <summary>
''' Uninstalls the Mouse Hook and free all resources, then stop processing messages to fire events.
''' </summary>
Public Sub Uninstall()

    If Not Me.IsInstalled Then
        Throw New MouseHookNotInstalledException

    Else
        Me.IsEnabled = False
        Me.IsInstalled = False
        Me.Finalize()

    End If

End Sub

''' <summary>
''' Temporally disables the Mouse Hook events.
''' To Re-enable the events, call the <see cref="Enable"/> method.
''' </summary>
Public Sub Disable()

    If Not Me.IsInstalled Then
        Throw New MouseHookNotInstalledException

    ElseIf Not Me.IsEnabled Then
        Throw New MouseHookNotEnabledException

    Else
        Me.IsEnabled = False

    End If

End Sub

''' <summary>
''' Re-enables the Mouse Hook events.
''' </summary>
Public Sub Enable()

    If Not Me.IsInstalled Then
        Throw New MouseHookNotInstalledException

    ElseIf Me.IsEnabled Then
        Throw New MouseHookEnabledException

    Else
        Me.IsEnabled = True

    End If

End Sub

#End Region

#Region " Private Methods "

''' <summary>
''' Determines whether the Visual Studio Hosting Process is enabled on the current application.
''' </summary>
''' <returns><c>true</c> if Visual Studio Hosting Process is enabled; otherwise, <c>false</c>.</returns>
Private Function IsVisualStudioHostingProcessEnabled() As Boolean
    Return AppDomain.CurrentDomain.FriendlyName.EndsWith("vshost.exe", StringComparison.OrdinalIgnoreCase)
End Function

Private Function LowLevelMouseProc(ByVal nCode As Integer,
                                   ByVal wParam As NativeMethods.WindowsMessages,
                                   ByVal lParam As IntPtr) As Integer

    If Not Me.IsEnabled Then
        Return CInt(NativeMethods.CallNextHookEx(MouseHook, nCode, New IntPtr(wParam), lParam))
    End If

    Static leftClickTime As Integer = 0I ' Determines a left button double-click.
    Static rightClickTime As Integer = 0I ' Determines a right button double-click.
    Static middleClickTime As Integer = 0I ' Determines a middle button double-click.

    If nCode = 0I Then

        Dim x As Integer
        Dim y As Integer

        Dim mouseStruct As NativeMethods.MsllHookStruct
        mouseStruct = CType(Marshal.PtrToStructure(lParam, mouseStruct.GetType()), 
                            NativeMethods.MsllHookStruct)

        ' Fix X coordinate.
        Select Case mouseStruct.Pt.X

            Case Is <= 0I
                If mouseStruct.Pt.X >= Me.WorkingArea.Location.X Then
                    x = mouseStruct.Pt.X

                ElseIf mouseStruct.Pt.X <= Me.WorkingArea.Location.X Then

                    If mouseStruct.Pt.X <= (Me.WorkingArea.Location.X - Me.WorkingArea.Width) Then
                        x = (Me.WorkingArea.Location.X - Me.WorkingArea.Width)
                    Else
                        x = mouseStruct.Pt.X

                    End If

                End If

            Case Is >= Me.WorkingArea.Width
                x = Me.WorkingArea.Width

            Case Else
                x = mouseStruct.Pt.X

        End Select

        ' Fix Y coordinate.
        Select Case mouseStruct.Pt.Y

            Case Is >= Me.WorkingArea.Height
                y = Me.WorkingArea.Height

            Case Is <= 0I
                y = 0I

            Case Else
                y = mouseStruct.Pt.Y

        End Select

        If x <= Me.WorkingArea.Width AndAlso
           y < Me.WorkingArea.Height AndAlso
           mouseStruct.Pt.X > Me.WorkingArea.Width Then
            Return CInt(NativeMethods.CallNextHookEx(MouseHook, nCode, New IntPtr(wParam), lParam))

        ElseIf x <= Me.WorkingArea.Width AndAlso
               y < Me.WorkingArea.Height AndAlso
               mouseStruct.Pt.X < Me.WorkingArea.X Then
            Return CInt(NativeMethods.CallNextHookEx(MouseHook, nCode, New IntPtr(wParam), lParam))

        ElseIf x = Me.WorkingArea.Width AndAlso
               y < Me.WorkingArea.Height Then

            If Not Me.WorkingArea.Contains(x - 1, y) Then
                Return CInt(NativeMethods.CallNextHookEx(MouseHook, nCode, New IntPtr(wParam), lParam))
            End If

        ElseIf x < Me.WorkingArea.Width AndAlso
               y = Me.WorkingArea.Height Then

            If Not Me.WorkingArea.Contains(x, y - 1) Then
                Return CInt(NativeMethods.CallNextHookEx(MouseHook, nCode, New IntPtr(wParam), lParam))
            End If

        End If

        Select Case wParam

            Case NativeMethods.WindowsMessages.WM_MOUSEMOVE
                RaiseEvent MouseMove(Me, New Point(x, y))

            Case NativeMethods.WindowsMessages.WM_LBUTTONDOWN
                RaiseEvent MouseLeftDown(Me, New Point(x, y))

            Case NativeMethods.WindowsMessages.WM_LBUTTONUP
                If leftClickTime <> 0 Then
                    leftClickTime = Environment.TickCount() - leftClickTime
                End If

                If (leftClickTime <> 0I) AndAlso (leftClickTime < NativeMethods.GetDoubleClickTime()) Then
                    leftClickTime = 0I
                    If Not Me.SuppressMouseUpEventWhenDoubleClick Then
                        RaiseEvent MouseLeftUp(Me, New Point(x, y))
                    End If
                    RaiseEvent MouseLeftDoubleClick(Me, New Point(x, y))

                Else
                    leftClickTime = Environment.TickCount()
                    RaiseEvent MouseLeftUp(Me, New Point(x, y))

                End If

            Case NativeMethods.WindowsMessages.WM_RBUTTONDOWN
                RaiseEvent MouseRightDown(Me, New Point(x, y))

            Case NativeMethods.WindowsMessages.WM_RBUTTONUP
                If rightClickTime <> 0I Then
                    rightClickTime = Environment.TickCount() - rightClickTime
                End If

                If (rightClickTime <> 0I) AndAlso (rightClickTime < NativeMethods.GetDoubleClickTime()) Then
                    rightClickTime = 0I
                    If Not Me.SuppressMouseUpEventWhenDoubleClick Then
                        RaiseEvent MouseRightUp(Me, New Point(x, y))
                    End If
                    RaiseEvent MouseRightDoubleClick(Me, New Point(x, y))

                Else
                    rightClickTime = Environment.TickCount()
                    RaiseEvent MouseRightUp(Me, New Point(x, y))

                End If

            Case NativeMethods.WindowsMessages.WM_MBUTTONDOWN
                RaiseEvent MouseMiddleDown(Me, New Point(x, y))

            Case NativeMethods.WindowsMessages.WM_MBUTTONUP
                If middleClickTime <> 0I Then
                    middleClickTime = Environment.TickCount() - middleClickTime
                End If

                If (middleClickTime <> 0I) AndAlso (middleClickTime < NativeMethods.GetDoubleClickTime()) Then
                    middleClickTime = 0I
                    If Not Me.SuppressMouseUpEventWhenDoubleClick Then
                        RaiseEvent MouseMiddleUp(Me, New Point(x, y))
                    End If
                    RaiseEvent MouseMiddleDoubleClick(Me, New Point(x, y))

                Else
                    middleClickTime = Environment.TickCount()
                    RaiseEvent MouseMiddleUp(Me, New Point(x, y))

                End If

            Case NativeMethods.WindowsMessages.WM_MOUSEWHEEL
                RaiseEvent MouseWheel(Me, New Point(x, y), If(mouseStruct.MouseData < 0I,
                                                             WheelDirection.WheelDown,
                                                             WheelDirection.WheelUp))

            Case Else
                ' Do Nothing
                Exit Select

        End Select

        Return CInt(NativeMethods.CallNextHookEx(MouseHook, nCode, New IntPtr(wParam), lParam))

    ElseIf nCode < 0I Then
        Return CInt(NativeMethods.CallNextHookEx(MouseHook, nCode, New IntPtr(wParam), lParam))

    Else ' nCode > 0
        Return CInt(NativeMethods.CallNextHookEx(MouseHook, nCode, New IntPtr(wParam), lParam))

    End If

End Function

#End Region

#Region "IDisposable Support"

''' <summary>
''' Flag to detect redundant calls at <see cref="Dispose"/> method.
''' </summary>
Private disposedValue As Boolean

Protected Sub Dispose(ByVal disposing As Boolean)

    Me.IsEnabled = False

    If Not Me.disposedValue Then

        If disposing Then ' Dispose managed state (managed objects).

        Else ' Free unmanaged resources (unmanaged objects).
            NativeMethods.UnhookWindowsHookEx(Me.MouseHook)

        End If

    End If

    Me.disposedValue = True

End Sub

Protected Overrides Sub Finalize()

    ' Do not change this code. Put cleanup code in method: Dispose(ByVal disposing As Boolean)

    Me.Dispose(disposing:=False)
    MyBase.Finalize()

End Sub

Private Sub Dispose() Implements IDisposable.Dispose

    ' Do not change this code. Put cleanup code in method: Dispose(ByVal disposing As Boolean)

    Me.Dispose(disposing:=True)
    GC.SuppressFinalize(obj:=Me)

End Sub

#End Region

End Class

#End Region

Answer 1

В этом посте недостаточно документации. Вы должны быть в состоянии опубликовать небольшой воспроизводимый пример. Утверждения типа "перестает работать" просто ничего не передают. И если вы получаете ошибки, пожалуйста, опубликуйте исключение.

С этим сказал...

Похоже, ваш обратный вызов - сборщик мусора. Вы должны хранить делегат в переменной, у которой есть хотя бы время жизни хука. Shared Ученик хороший кандидат.

Например:

'BAD!
Class MyClass
  Public Sub Run()
    Dim Hook as MouseHook = New MouseHook()

    'install, enable, etc...
  End Sub

  'Hook is not saved and will be collected after Run() ends
End Class

Должно быть:

'Better
Class MyClass
  Private Shared Hook as MouseHook

  Public Sub Run()
    Hook = New MouseHook()

    'install, enable, etc...
  End Sub

  'Now, Hook IS saved and will live on after Run() ends
End Class

Это очень просто, и вы должны адаптировать его к вашим потребностям. Опять же, это всего лишь предположение, поскольку на самом деле не достаточно информации, чтобы пойти дальше.