Question

经过多次搜索后，我最终使用此类进行全局键盘挂钩。链接：Global Hook post

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 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

End Class

效果很好。

我的应用程序正在执行需要几秒钟才能完成的操作（ftp会间隔上传小文件），在这段时间内，钩子会占用键盘。我当然不想要

我现在无法跳转到Async FtpWebRequest，因为它需要进行许多更改，所以我认为解决方案是让hoook在另一个线程中生效。

我该怎么做？

编辑：建议是将我耗费时间的操作（上传）转移到另一个线程。这样做我面临其他问题。因为耗时的任务（上传）在计时器中，我将不得不重写大部分以便同步文件 - >保存与文件 - >上传，我不介意应用程序锁定3-4秒。我的主意是松开皮艇3-4秒......

Answer 1

不要让钩子在不同的线程上运行（我认为你不能，它基于消息循环）;相反，只需在另一个线程中运行您的任务。这可能是最简单的方法：

Call New Thread(Sub()
                    ' Do stuff here
                End Sub) With {.IsBackground = True}.Start()

Answer 2

您需要在后台线程上运行耗时的任务使用ThreadPool或Task。

如何在单独的线程上设置全局键盘钩子？

2 个答案: