C#挂钩全局键盘事件-.net 4.0
本文关键字：net 事件 键盘 全局 | 更新日期: 2023-09-27 18:26:57
作为我正在开发的媒体播放器应用程序的一部分，我想为媒体控制键（播放、向前跳过、向后跳过等）挂起全局按键。
我已经搜索了大约2个小时，试图找到一个解决方案，但我找不到一个有效的。我找到了几个关于同一件事的Stack Overflow答案，但都不起作用。
我尝试了MouseKeyHook NuGet包，但它永远不会触发事件。我也尝试了FMUtils.KeyboardHook包，但发生了同样的事情，只是控制台上打印出它在启动后立即关闭了挂钩——我不知道为什么，即使在查看了源代码之后也是如此。
我试图获取此代码项目http://www.codeproject.com/Articles/18638/Using-Window-Messages-to-Implement-Global-System-H但我甚至无法运行演示，两个演示都出现了我无法追踪的奇怪错误。
我的问题是，在.NET4.0中捕获键盘按压的已知工作方式是什么，当我的WinForms应用程序没有聚焦时，我可以使用它来捕获键盘按压？
这是我在过去X几年中为几个项目使用的代码。应该可以正常工作（对于Windows上的任何.NET版本）。
public class KeyboardHook : IDisposable
{
bool Global = false;
public delegate void LocalKeyEventHandler(Keys key, bool Shift, bool Ctrl, bool Alt);
public event LocalKeyEventHandler KeyDown;
public event LocalKeyEventHandler KeyUp;
public delegate int CallbackDelegate(int Code, int W, int L);
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct KBDLLHookStruct
{
public Int32 vkCode;
public Int32 scanCode;
public Int32 flags;
public Int32 time;
public Int32 dwExtraInfo;
}
[DllImport("user32", CallingConvention = CallingConvention.StdCall)]
private static extern int SetWindowsHookEx(HookType idHook, CallbackDelegate lpfn, int hInstance, int threadId);
[DllImport("user32", CallingConvention = CallingConvention.StdCall)]
private static extern bool UnhookWindowsHookEx(int idHook);
[DllImport("user32", CallingConvention = CallingConvention.StdCall)]
private static extern int CallNextHookEx(int idHook, int nCode, int wParam, int lParam);
[DllImport("kernel32.dll", CallingConvention = CallingConvention.StdCall)]
private static extern int GetCurrentThreadId();
public enum HookType : int
{
WH_JOURNALRECORD = 0,
WH_JOURNALPLAYBACK = 1,
WH_KEYBOARD = 2,
WH_GETMESSAGE = 3,
WH_CALLWNDPROC = 4,
WH_CBT = 5,
WH_SYSMSGFILTER = 6,
WH_MOUSE = 7,
WH_HARDWARE = 8,
WH_DEBUG = 9,
WH_SHELL = 10,
WH_FOREGROUNDIDLE = 11,
WH_CALLWNDPROCRET = 12,
WH_KEYBOARD_LL = 13,
WH_MOUSE_LL = 14
}
private int HookID = 0;
CallbackDelegate TheHookCB = null;
//Start hook
public KeyboardHook(bool Global)
{
this.Global = Global;
TheHookCB = new CallbackDelegate(KeybHookProc);
if (Global)
{
HookID = SetWindowsHookEx(HookType.WH_KEYBOARD_LL, TheHookCB,
0, //0 for local hook. eller hwnd til user32 for global
0); //0 for global hook. eller thread for hooken
}
else
{
HookID = SetWindowsHookEx(HookType.WH_KEYBOARD, TheHookCB,
0, //0 for local hook. or hwnd to user32 for global
GetCurrentThreadId()); //0 for global hook. or thread for the hook
}
}
bool IsFinalized = false;
~KeyboardHook()
{
if (!IsFinalized)
{
UnhookWindowsHookEx(HookID);
IsFinalized = true;
}
}
public void Dispose()
{
if (!IsFinalized)
{
UnhookWindowsHookEx(HookID);
IsFinalized = true;
}
}
//The listener that will trigger events
private int KeybHookProc(int Code, int W, int L)
{
KBDLLHookStruct LS = new KBDLLHookStruct();
if (Code < 0)
{
return CallNextHookEx(HookID, Code, W, L);
}
try
{
if (!Global)
{
if (Code == 3)
{
IntPtr ptr = IntPtr.Zero;
int keydownup = L >> 30;
if (keydownup == 0)
{
if (KeyDown != null) KeyDown((Keys)W, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
if (keydownup == -1)
{
if (KeyUp != null) KeyUp((Keys)W, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
//System.Diagnostics.Debug.WriteLine("Down: " + (Keys)W);
}
}
else
{
KeyEvents kEvent = (KeyEvents)W;
Int32 vkCode = Marshal.ReadInt32((IntPtr)L); //Leser vkCode som er de første 32 bits hvor L peker.
if (kEvent != KeyEvents.KeyDown && kEvent != KeyEvents.KeyUp && kEvent != KeyEvents.SKeyDown && kEvent != KeyEvents.SKeyUp)
{
}
if (kEvent == KeyEvents.KeyDown || kEvent == KeyEvents.SKeyDown)
{
if (KeyDown != null) KeyDown((Keys)vkCode, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
if (kEvent == KeyEvents.KeyUp || kEvent == KeyEvents.SKeyUp)
{
if (KeyUp != null) KeyUp((Keys)vkCode, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
}
}
catch (Exception)
{
//Ignore all errors...
}
return CallNextHookEx(HookID, Code, W, L);
}
public enum KeyEvents
{
KeyDown = 0x0100,
KeyUp = 0x0101,
SKeyDown = 0x0104,
SKeyUp = 0x0105
}
[DllImport("user32.dll")]
static public extern short GetKeyState(System.Windows.Forms.Keys nVirtKey);
public static bool GetCapslock()
{
return Convert.ToBoolean(GetKeyState(System.Windows.Forms.Keys.CapsLock)) & true;
}
public static bool GetNumlock()
{
return Convert.ToBoolean(GetKeyState(System.Windows.Forms.Keys.NumLock)) & true;
}
public static bool GetScrollLock()
{
return Convert.ToBoolean(GetKeyState(System.Windows.Forms.Keys.Scroll)) & true;
}
public static bool GetShiftPressed()
{
int state = GetKeyState(System.Windows.Forms.Keys.ShiftKey);
if (state > 1 || state < -1) return true;
return false;
}
public static bool GetCtrlPressed()
{
int state = GetKeyState(System.Windows.Forms.Keys.ControlKey);
if (state > 1 || state < -1) return true;
return false;
}
public static bool GetAltPressed()
{
int state = GetKeyState(System.Windows.Forms.Keys.Menu);
if (state > 1 || state < -1) return true;
return false;
}
}
测试应用程序：
static class Program
{
[STAThread]
static void Main()
{
var kh = new KeyboardHook(true);
kh.KeyDown += Kh_KeyDown;
Application.Run();
}
private static void Kh_KeyDown(Keys key, bool Shift, bool Ctrl, bool Alt)
{
Debug.WriteLine("The Key: " + key);
}
}
它可以进行一些代码清理，但我并没有因为它的工作而烦恼。
以下是该类的一个固定版本，它不会产生访问冲突错误：
public class KeyboardHook : IDisposable
{
bool Global = false;
public delegate void ErrorEventHandler(Exception e);
public delegate void LocalKeyEventHandler(Keys key, bool Shift, bool Ctrl, bool Alt);
public event LocalKeyEventHandler KeyDown;
public event LocalKeyEventHandler KeyUp;
public event ErrorEventHandler OnError;
public delegate int CallbackDelegate(int Code, IntPtr W, IntPtr L);
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct KBDLLHookStruct
{
public Int32 vkCode;
public Int32 scanCode;
public Int32 flags;
public Int32 time;
public Int32 dwExtraInfo;
}
[DllImport("user32", CallingConvention = CallingConvention.StdCall)]
private static extern IntPtr SetWindowsHookEx(HookType idHook, CallbackDelegate lpfn, IntPtr hInstance, int threadId);
[DllImport("user32", CallingConvention = CallingConvention.StdCall)]
private static extern bool UnhookWindowsHookEx(IntPtr idHook);
[DllImport("user32", CallingConvention = CallingConvention.StdCall)]
private static extern int CallNextHookEx(IntPtr idHook, int nCode, IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll", CallingConvention = CallingConvention.StdCall)]
private static extern int GetCurrentThreadId();
[DllImport("kernel32.dll")]
static extern IntPtr LoadLibrary(string lpFileName);
public enum HookType : int
{
WH_JOURNALRECORD = 0,
WH_JOURNALPLAYBACK = 1,
WH_KEYBOARD = 2,
WH_GETMESSAGE = 3,
WH_CALLWNDPROC = 4,
WH_CBT = 5,
WH_SYSMSGFILTER = 6,
WH_MOUSE = 7,
WH_HARDWARE = 8,
WH_DEBUG = 9,
WH_SHELL = 10,
WH_FOREGROUNDIDLE = 11,
WH_CALLWNDPROCRET = 12,
WH_KEYBOARD_LL = 13,
WH_MOUSE_LL = 14
}
private IntPtr HookID = IntPtr.Zero;
CallbackDelegate TheHookCB = null;
//Start hook
public KeyboardHook(bool Global)
{
this.Global = Global;
TheHookCB = new CallbackDelegate(KeybHookProc);
if (Global)
{
IntPtr hInstance = LoadLibrary("User32");
HookID = SetWindowsHookEx(HookType.WH_KEYBOARD_LL, TheHookCB,
hInstance, //0 for local hook. or hwnd to user32 for global
0); //0 for global hook. eller thread for hooken
}
else
{
HookID = SetWindowsHookEx(HookType.WH_KEYBOARD, TheHookCB,
IntPtr.Zero, //0 for local hook. or hwnd to user32 for global
GetCurrentThreadId()); //0 for global hook. or thread for the hook
}
}
public void test()
{
if (OnError != null) OnError(new Exception("test"));
}
bool IsFinalized = false;
~KeyboardHook()
{
if (!IsFinalized)
{
UnhookWindowsHookEx(HookID);
IsFinalized = true;
}
}
public void Dispose()
{
if (!IsFinalized)
{
UnhookWindowsHookEx(HookID);
IsFinalized = true;
}
}
[STAThread]
//The listener that will trigger events
private int KeybHookProc(int Code, IntPtr W, IntPtr L)
{
KBDLLHookStruct LS = new KBDLLHookStruct();
if (Code < 0)
{
return CallNextHookEx(HookID, Code, W, L);
}
try
{
if (!Global)
{
if (Code == 3)
{
IntPtr ptr = IntPtr.Zero;
int keydownup = L.ToInt32() >> 30;
if (keydownup == 0)
{
if (KeyDown != null) KeyDown((Keys)W, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
if (keydownup == -1)
{
if (KeyUp != null) KeyUp((Keys)W, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
//System.Diagnostics.Debug.WriteLine("Down: " + (Keys)W);
}
}
else
{
KeyEvents kEvent = (KeyEvents)W;
Int32 vkCode = Marshal.ReadInt32((IntPtr)L); //Leser vkCode som er de første 32 bits hvor L peker.
if (kEvent != KeyEvents.KeyDown && kEvent != KeyEvents.KeyUp && kEvent != KeyEvents.SKeyDown && kEvent != KeyEvents.SKeyUp)
{
}
if (kEvent == KeyEvents.KeyDown || kEvent == KeyEvents.SKeyDown)
{
if (KeyDown != null) KeyDown((Keys)vkCode, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
if (kEvent == KeyEvents.KeyUp || kEvent == KeyEvents.SKeyUp)
{
if (KeyUp != null) KeyUp((Keys)vkCode, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
}
}
catch (Exception e)
{
if (OnError != null) OnError(e);
//Ignore all errors...
}
return CallNextHookEx(HookID, Code, W, L);
}
public enum KeyEvents
{
KeyDown = 0x0100,
KeyUp = 0x0101,
SKeyDown = 0x0104,
SKeyUp = 0x0105
}
[DllImport("user32.dll")]
static public extern short GetKeyState(System.Windows.Forms.Keys nVirtKey);
public static bool GetCapslock()
{
return Convert.ToBoolean(GetKeyState(System.Windows.Forms.Keys.CapsLock)) & true;
}
public static bool GetNumlock()
{
return Convert.ToBoolean(GetKeyState(System.Windows.Forms.Keys.NumLock)) & true;
}
public static bool GetScrollLock()
{
return Convert.ToBoolean(GetKeyState(System.Windows.Forms.Keys.Scroll)) & true;
}
public static bool GetShiftPressed()
{
int state = GetKeyState(System.Windows.Forms.Keys.ShiftKey);
if (state > 1 || state < -1) return true;
return false;
}
public static bool GetCtrlPressed()
{
int state = GetKeyState(System.Windows.Forms.Keys.ControlKey);
if (state > 1 || state < -1) return true;
return false;
}
public static bool GetAltPressed()
{
int state = GetKeyState(System.Windows.Forms.Keys.Menu);
if (state > 1 || state < -1) return true;
return false;
}
}