Question

我正在尝试禁用Windows密钥。在运行应用程序时，我收到错误＆＃34;检测到CallbackOnCollectedDelegate＆＃34;以下是我的代码

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

非常感谢任何帮助

Answer 1

问题与this post相同。不同之处在于他们正在使用C＃。但是，VB正在做同样的事情;为你生成一个代表。作为参考，这是反编译代码在表单的Load事件中的样子。

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。我不会在这里彻底改变@HansPassant's answer，因为他在描述问题和解决方案方面表现出色;只说你需要存储自己对LowLevelKeyboardProcDelegate委托的引用。

＆＃34;检测到CallbackOnCollectedDelegate＆＃34;

1 个答案: