键盘挂钩错误

Question

我在获取某些代码时遇到了一些麻烦。那就是：

Imports System.Runtime.InteropServices 

Public Class KeyboardHook 

    <DllImport("User32.dll", CharSet:=CharSet.Auto, CallingConvention:=CallingConvention.StdCall)> _ 
    Private Overloads Shared Function SetWindowsHookEx(ByVal idHook As Integer, ByVal HookProc As KBDLLHookProc, ByVal hInstance As IntPtr, ByVal wParam As Integer) As Integer 
    End Function 
    <DllImport("User32.dll", CharSet:=CharSet.Auto, CallingConvention:=CallingConvention.StdCall)> _ 
    Private Overloads Shared Function CallNextHookEx(ByVal idHook As Integer, ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As Integer 
    End Function 
    <DllImport("User32.dll", CharSet:=CharSet.Auto, CallingConvention:=CallingConvention.StdCall)> _ 
    Private Overloads Shared Function UnhookWindowsHookEx(ByVal idHook As Integer) As Boolean 
    End Function 

    <StructLayout(LayoutKind.Sequential)> _ 
    Private Structure KBDLLHOOKSTRUCT 
     Public vkCode As UInt32 
     Public scanCode As UInt32 
     Public flags As KBDLLHOOKSTRUCTFlags 
     Public time As UInt32 
     Public dwExtraInfo As UIntPtr 
    End Structure 

    <Flags()> _ 
    Private Enum KBDLLHOOKSTRUCTFlags As UInt32 
     LLKHF_EXTENDED = &H1 
     LLKHF_INJECTED = &H10 
     LLKHF_ALTDOWN = &H20 
     LLKHF_UP = &H80 
    End Enum 

    Public Shared Event KeyDown(ByVal Key As Keys) 
    Public Shared Event KeyUp(ByVal Key As Keys) 

    Private Const WH_KEYBOARD_LL As Integer = 13 
    Private Const HC_ACTION As Integer = 0 
    Private Const WM_KEYDOWN = &H100 
    Private Const WM_KEYUP = &H101 
    Private Const WM_SYSKEYDOWN = &H104 
    Private Const WM_SYSKEYUP = &H105 

    Private Delegate Function KBDLLHookProc(ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As Integer 

    Private KBDLLHookProcDelegate As KBDLLHookProc = New KBDLLHookProc(AddressOf KeyboardProc) 
    Private HHookID As IntPtr = IntPtr.Zero 

    Private WithEvents kbHook As New KeyboardHook 


    Private Function KeyboardProc(ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As Integer 
     If (nCode = HC_ACTION) Then 
      Dim struct As KBDLLHOOKSTRUCT 
      Select Case wParam 
       Case WM_KEYDOWN, WM_SYSKEYDOWN 
        RaiseEvent KeyDown(CType(CType(Marshal.PtrToStructure(lParam, struct.GetType()), KBDLLHOOKSTRUCT).vkCode, Keys)) 
       Case WM_KEYUP, WM_SYSKEYUP 
        RaiseEvent KeyUp(CType(CType(Marshal.PtrToStructure(lParam, struct.GetType()), KBDLLHOOKSTRUCT).vkCode, Keys)) 
      End Select 
     End If 
     Return CallNextHookEx(IntPtr.Zero, nCode, wParam, lParam) 
    End Function 

    Public Sub New() 
     HHookID = SetWindowsHookEx(WH_KEYBOARD_LL, KBDLLHookProcDelegate, System.Runtime.InteropServices.Marshal.GetHINSTANCE(System.Reflection.Assembly.GetExecutingAssembly.GetModules()(0)).ToInt32, 0) 
     If HHookID = IntPtr.Zero Then 
      Throw New Exception("Could not set keyboard hook") 
     End If 
    End Sub 

    Protected Overrides Sub Finalize() 
     If Not HHookID = IntPtr.Zero Then 
      UnhookWindowsHookEx(HHookID) 
     End If 
     MyBase.Finalize() 
    End Sub 

    Private Sub kbHook_KeyDown(ByVal Key As System.Windows.Forms.Keys) Handles kbHook.KeyDown 
     Debug.WriteLine(Key.ToString) 
    End Sub 
    Private Sub kbHook_KeyUp(ByVal Key As System.Windows.Forms.Keys) Handles kbHook.KeyUp 
     Debug.WriteLine(Key) 
    End Sub 

End Class 

我已设置：项目 - > [项目名称]属性 - >调试 - >取消选中“启用在Visual Studio宿主进程”

我收到以下错误：

System.StackOverflowException was unhandled 
An unhandled exception of type 'System.StackOverflowException' occurred in System.Windows.Forms.dll 

请问在这种情况下可以得到一些帮助吗？

感谢

西蒙

Answer 1

Private WithEvents kbHook As New KeyboardHook 

你的KeyboardHook构造函数初始化类的成员，包括kbHook。其中，由于As New关键字构造了一个KeyboardHook的新实例。初始化类的成员，包括kbHook。其中，... Kaboom！

删除kbHook并将其放在其他地方，如在窗体中。

请注意，您的代码无法在AnyCPU生效的64位操作系统上运行，Marshal.GetHINSTANCE（）强制关闭。如果您需要帮助，请提出另一个问题。