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我想了解鍵盤掛鉤如何工作和失敗。我收集了一些我想要的代碼。
我想要做的是攔截某些鍵盤輸入並執行我的代碼，而不是將這些特定的鍵盤輸入傳遞迴應用程序。我的代碼能夠攔截鍵盤輸入並執行我的代碼，但鍵盤輸入總是在代碼執行後傳遞到應用程序。有什麼建議麼？鍵盤掛鉤，防止鍵盤輸入到應用程序
Imports System
Imports System.Runtime.CompilerServices
Imports System.Runtime.InteropServices
Imports System.Windows.Forms
Friend Class KeyboardHooking
' Methods
<DllImport("user32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
Private Shared Function CallNextHookEx(ByVal hhk As IntPtr, ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
End Function
<DllImport("kernel32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
Private Shared Function GetModuleHandle(ByVal lpModuleName As String) As IntPtr
End Function
Private Shared Function HookCallback(ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As Integer
If ((nCode >= 0) AndAlso (nCode = 0)) Then
Dim keyData As Keys = DirectCast(CInt(wParam), Keys)
If ((BindingFunctions.IsKeyDown(Keys.ControlKey) AndAlso BindingFunctions.IsKeyDown(Keys.ShiftKey)) AndAlso BindingFunctions.IsKeyDown(My.Settings.keyLinkQuickToDB)) Then
linkQuickToDB()
'Qty Changer
ElseIf ((BindingFunctions.IsKeyDown(Keys.ControlKey) AndAlso BindingFunctions.IsKeyDown(Keys.ShiftKey)) AndAlso BindingFunctions.IsKeyDown(My.Settings.keyQtyChange)) Then
qtyChanger()
End If
End If
Return CInt(KeyboardHooking.CallNextHookEx(KeyboardHooking._hookID, nCode, wParam, lParam))
End Function
Public Shared Sub ReleaseHook()
KeyboardHooking.UnhookWindowsHookEx(KeyboardHooking._hookID)
End Sub
Public Shared Sub SetHook()
KeyboardHooking._hookID = KeyboardHooking.SetWindowsHookEx(2, KeyboardHooking._proc, IntPtr.Zero, Convert.ToUInt32(AppDomain.GetCurrentThreadId))
End Sub
<DllImport("user32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
Private Shared Function SetWindowsHookEx(ByVal idHook As Integer, ByVal lpfn As LowLevelKeyboardProc, ByVal hMod As IntPtr, ByVal dwThreadId As UInt32) As IntPtr
End Function
<DllImport("user32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
Private Shared Function UnhookWindowsHookEx(ByVal hhk As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function
' Fields
Private Shared _hookID As IntPtr = IntPtr.Zero
Private Shared _proc As LowLevelKeyboardProc = New LowLevelKeyboardProc(AddressOf KeyboardHooking.HookCallback)
Private Const WH_KEYBOARD As Integer = 2
Private Const WH_KEYBOARD_LL As Integer = 13
Private Const WM_KEYDOWN As Integer = &H100
' Nested Types
Public Delegate Function LowLevelKeyboardProc(ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As Integer
End Class
Public Class BindingFunctions
' Methods
<DllImport("user32.dll")> _
Private Shared Function GetKeyState(ByVal nVirtKey As Integer) As Short
End Function
Public Shared Function IsKeyDown(ByVal keys As Keys) As Boolean
Return ((BindingFunctions.GetKeyState(CInt(keys)) And &H8000) = &H8000)
End Function
End Class