C＃钩子全局键盘事件-.net 4.0 [英] C# Hook Global Keyboard Events - .net 4.0
问题描述
作为我正在处理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，向后跳等）挂接全局按键。
As part of a media player application I'm working on, I want to hook global keypresses for media control keys (play, skip forward, skip back, etc).
我一直在搜索约2个小时，试图找到一种解决方案-但找不到有效的解决方案。我发现了几个关于同一件事的Stackoverflow答案，但没有一个起作用。
I've been searching for about 2 hours now trying to find a solution - but I couldn't find one that worked. I found several Stackoverflow answers about the same thing, but none of them worked.
我尝试了 MouseKeyHook NuGet程序包，但它永远不会触发该事件。我尝试了 FMUtils.KeyboardHook 软件包也发生了，但是发生了同样的事情，除了它在控制台中打印出来，它在启动后立即关闭了钩子-而且我不知道为什么，在查看源代码后发生了事件。
I tried the MouseKeyHook NuGet package, but it would never fire the event. I tried the FMUtils.KeyboardHook package too, but the same thing happened, except it printed in the console that it shut down the hook right after starting it - and I have no idea why, event after looking at the source code.
我试图获得此代码项目项目 http://www.codeproject.com/Articles/18638/Using-Window-Messages-to-Implement-Global-System-H ，但我无法甚至没有运行演示，两个演示都抛出了我无法跟踪的奇怪错误。
I tried to get this codeproject project http://www.codeproject.com/Articles/18638/Using-Window-Messages-to-Implement-Global-System-H but I couldn't even run the demo, both the demos just threw weird errors that I couldn't trace.
我的问题是，在 .net 4.0 中捕获键盘按键的已知工作方式是什么？我的Winforms应用程序不集中？
My question is, what is a known to work way of capturing keyboard presses in .net 4.0 that I can use to capture keyboard presses when my Winforms application isn't focused?
推荐答案
这是过去X年来我在多个项目中一直使用的代码。应该没有问题（对于Windows上的任何.Net版本）。希望对您有帮助。
Here is the code I have been using for several projects for the last X years. Should work with no issues (for any .Net version on Windows). Hope it helps you.
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，但是我有不会因为它的工作而烦恼。
It could do with some code cleanup, but I have not bothered as it works.
这篇关于C＃钩子全局键盘事件-.net 4.0的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
