“检测到CallbackOnCollectedDelegate”

Question

我试图禁用Windows键。转Bt基因在运行应用程序我得到一个错误“检测CallbackOnCollectedDelegate”下面是我的代码

Declare Function SetWindowsHookEx Lib "user32" Alias "SetWindowsHookExA" (ByVal idHook As Integer, ByVal lpfn As LowLevelKeyboardProcDelegate, ByVal hMod As IntPtr, ByVal dwThreadId As Integer) As IntPtr 
Declare Function UnhookWindowsHookEx Lib "user32" Alias "UnhookWindowsHookEx" (ByVal hHook As IntPtr) As Boolean 
Declare Function CallNextHookEx Lib "user32" Alias "CallNextHookEx" (ByVal hHook As IntPtr, ByVal nCode As Integer, ByVal wParam As Integer, ByRef lParam As KBDLLHOOKSTRUCT) As Integer 
Delegate Function LowLevelKeyboardProcDelegate(ByVal nCode As Integer, ByVal wParam As Integer, ByRef lParam As KBDLLHOOKSTRUCT) As Integer 

Const WH_KEYBOARD_LL As Integer = 13 

Structure KBDLLHOOKSTRUCT 
    Dim vkCode As Integer 
    Dim scanCode As Integer 
    Dim flags As Integer 
    Dim time As Integer 
    Dim dwExtraInfo As Integer 
End Structure 

Dim intLLKey As IntPtr 

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load 
    intLLKey = SetWindowsHookEx(WH_KEYBOARD_LL, AddressOf LowLevelKeyboardProc, IntPtr.Zero, 0) 
End Sub 

Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing 
    UnhookWindowsHookEx(intLLKey) 
End Sub 

Private Function LowLevelKeyboardProc(ByVal nCode As Integer, ByVal wParam As Integer, ByRef lParam As KBDLLHOOKSTRUCT) As Integer 
    Dim blnEat As Boolean = False 
    Select Case wParam 
     Case 256, 257, 260, 261 
      'Alt+Tab, Alt+Esc, Ctrl+Esc, Windows Key  
      blnEat = ((lParam.vkCode = 9) AndAlso (lParam.flags = 32)) Or 
      ((lParam.vkCode = 27) AndAlso (lParam.flags = 32)) Or 
      ((lParam.vkCode = 27) AndAlso (lParam.flags = 0)) Or 
      ((lParam.vkCode = 91) AndAlso (lParam.flags = 1)) Or 
      ((lParam.vkCode = 92) AndAlso (lParam.flags = 1)) 
    End Select 

    If blnEat = True Then 
     Return 1 
    Else 
     Return CallNextHookEx(IntPtr.Zero, nCode, wParam, lParam) 
    End If 
End Function 

任何帮助是非常赞赏

Answer 1

的问题是一样的this post。不同之处在于他们使用C＃。但是，VB正在做同样的事情;为您生成一个委托。作为参考，这是您的表单的Load事件中反编译的代码的样子。

Private Sub Form1_Load(sender As Object, e As EventArgs) 
    Me.intLLKey = Form1.SetWindowsHookEx(13, New Form1.LowLevelKeyboardProcDelegate(Me.LowLevelKeyboardProc), IntPtr.Zero, 0) 
End Sub 

请注意，它正在为您创建一个LowLevelKeyboardProcDelegate委托。我不会在这里完全重复@HansPassant's answer，因为他在描述问题和解决方案方面做得非常出色;只能说你需要存储自己对LowLevelKeyboardProcDelegate委托的引用。