.net C#应用程序中的全局键盘捕获
我想在我的应用程序中捕获一个键盘快捷键,并在用户在应用程序之外按下键盘组合时触发一个对话框。类似于谷歌桌面搜索的Ctrl键,Ctrl键打开搜索对话框 我尝试过使用一些键盘钩子模块,这些模块基本上使用Win32 interop来获得这种效果,但我尝试过的每个实现都会在一定程度上限制键盘,当应用程序执行某些密集型操作时,会出现奇怪的行为。例如加载大量数据,这将导致键盘和鼠标锁定 我正在寻找一种轻量级的解决方案,它可以在不束缚键盘和鼠标的情况下实现这一点。Stephen Toub关于在C#中实现全局键盘挂钩的介绍:.net C#应用程序中的全局键盘捕获,.net,events,keyboard-hook,.net,Events,Keyboard Hook,我想在我的应用程序中捕获一个键盘快捷键,并在用户在应用程序之外按下键盘组合时触发一个对话框。类似于谷歌桌面搜索的Ctrl键,Ctrl键打开搜索对话框 我尝试过使用一些键盘钩子模块,这些模块基本上使用Win32 interop来获得这种效果,但我尝试过的每个实现都会在一定程度上限制键盘,当应用程序执行某些密集型操作时,会出现奇怪的行为。例如加载大量数据,这将导致键盘和鼠标锁定 我正在寻找一种轻量级的解决方案,它可以在不束缚键盘和鼠标的情况下实现这一点。Stephen Toub关于在C#中实现全局键
如果一个全局热键就足够了,那么就可以实现这个技巧了
using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.InteropServices;
namespace SnagFree.TrayApp.Core
{
class GlobalKeyboardHookEventArgs : HandledEventArgs
{
public GlobalKeyboardHook.KeyboardState KeyboardState { get; private set; }
public GlobalKeyboardHook.LowLevelKeyboardInputEvent KeyboardData { get; private set; }
public GlobalKeyboardHookEventArgs(
GlobalKeyboardHook.LowLevelKeyboardInputEvent keyboardData,
GlobalKeyboardHook.KeyboardState keyboardState)
{
KeyboardData = keyboardData;
KeyboardState = keyboardState;
}
}
//Based on https://gist.github.com/Stasonix
class GlobalKeyboardHook : IDisposable
{
public event EventHandler<GlobalKeyboardHookEventArgs> KeyboardPressed;
public GlobalKeyboardHook()
{
_windowsHookHandle = IntPtr.Zero;
_user32LibraryHandle = IntPtr.Zero;
_hookProc = LowLevelKeyboardProc; // we must keep alive _hookProc, because GC is not aware about SetWindowsHookEx behaviour.
_user32LibraryHandle = LoadLibrary("User32");
if (_user32LibraryHandle == IntPtr.Zero)
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to load library 'User32.dll'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_windowsHookHandle = SetWindowsHookEx(WH_KEYBOARD_LL, _hookProc, _user32LibraryHandle, 0);
if (_windowsHookHandle == IntPtr.Zero)
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to adjust keyboard hooks for '{Process.GetCurrentProcess().ProcessName}'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
// because we can unhook only in the same thread, not in garbage collector thread
if (_windowsHookHandle != IntPtr.Zero)
{
if (!UnhookWindowsHookEx(_windowsHookHandle))
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to remove keyboard hooks for '{Process.GetCurrentProcess().ProcessName}'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_windowsHookHandle = IntPtr.Zero;
// ReSharper disable once DelegateSubtraction
_hookProc -= LowLevelKeyboardProc;
}
}
if (_user32LibraryHandle != IntPtr.Zero)
{
if (!FreeLibrary(_user32LibraryHandle)) // reduces reference to library by 1.
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to unload library 'User32.dll'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_user32LibraryHandle = IntPtr.Zero;
}
}
~GlobalKeyboardHook()
{
Dispose(false);
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
private IntPtr _windowsHookHandle;
private IntPtr _user32LibraryHandle;
private HookProc _hookProc;
delegate IntPtr HookProc(int nCode, IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll")]
private static extern IntPtr LoadLibrary(string lpFileName);
[DllImport("kernel32.dll", CharSet = CharSet.Auto)]
private static extern bool FreeLibrary(IntPtr hModule);
/// <summary>
/// The SetWindowsHookEx function installs an application-defined hook procedure into a hook chain.
/// You would install a hook procedure to monitor the system for certain types of events. These events are
/// associated either with a specific thread or with all threads in the same desktop as the calling thread.
/// </summary>
/// <param name="idHook">hook type</param>
/// <param name="lpfn">hook procedure</param>
/// <param name="hMod">handle to application instance</param>
/// <param name="dwThreadId">thread identifier</param>
/// <returns>If the function succeeds, the return value is the handle to the hook procedure.</returns>
[DllImport("USER32", SetLastError = true)]
static extern IntPtr SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hMod, int dwThreadId);
/// <summary>
/// The UnhookWindowsHookEx function removes a hook procedure installed in a hook chain by the SetWindowsHookEx function.
/// </summary>
/// <param name="hhk">handle to hook procedure</param>
/// <returns>If the function succeeds, the return value is true.</returns>
[DllImport("USER32", SetLastError = true)]
public static extern bool UnhookWindowsHookEx(IntPtr hHook);
/// <summary>
/// The CallNextHookEx function passes the hook information to the next hook procedure in the current hook chain.
/// A hook procedure can call this function either before or after processing the hook information.
/// </summary>
/// <param name="hHook">handle to current hook</param>
/// <param name="code">hook code passed to hook procedure</param>
/// <param name="wParam">value passed to hook procedure</param>
/// <param name="lParam">value passed to hook procedure</param>
/// <returns>If the function succeeds, the return value is true.</returns>
[DllImport("USER32", SetLastError = true)]
static extern IntPtr CallNextHookEx(IntPtr hHook, int code, IntPtr wParam, IntPtr lParam);
[StructLayout(LayoutKind.Sequential)]
public struct LowLevelKeyboardInputEvent
{
/// <summary>
/// A virtual-key code. The code must be a value in the range 1 to 254.
/// </summary>
public int VirtualCode;
/// <summary>
/// A hardware scan code for the key.
/// </summary>
public int HardwareScanCode;
/// <summary>
/// The extended-key flag, event-injected Flags, context code, and transition-state flag. This member is specified as follows. An application can use the following values to test the keystroke Flags. Testing LLKHF_INJECTED (bit 4) will tell you whether the event was injected. If it was, then testing LLKHF_LOWER_IL_INJECTED (bit 1) will tell you whether or not the event was injected from a process running at lower integrity level.
/// </summary>
public int Flags;
/// <summary>
/// The time stamp stamp for this message, equivalent to what GetMessageTime would return for this message.
/// </summary>
public int TimeStamp;
/// <summary>
/// Additional information associated with the message.
/// </summary>
public IntPtr AdditionalInformation;
}
public const int WH_KEYBOARD_LL = 13;
//const int HC_ACTION = 0;
public enum KeyboardState
{
KeyDown = 0x0100,
KeyUp = 0x0101,
SysKeyDown = 0x0104,
SysKeyUp = 0x0105
}
public const int VkSnapshot = 0x2c;
//const int VkLwin = 0x5b;
//const int VkRwin = 0x5c;
//const int VkTab = 0x09;
//const int VkEscape = 0x18;
//const int VkControl = 0x11;
const int KfAltdown = 0x2000;
public const int LlkhfAltdown = (KfAltdown >> 8);
public IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam)
{
bool fEatKeyStroke = false;
var wparamTyped = wParam.ToInt32();
if (Enum.IsDefined(typeof(KeyboardState), wparamTyped))
{
object o = Marshal.PtrToStructure(lParam, typeof(LowLevelKeyboardInputEvent));
LowLevelKeyboardInputEvent p = (LowLevelKeyboardInputEvent)o;
var eventArguments = new GlobalKeyboardHookEventArgs(p, (KeyboardState)wparamTyped);
EventHandler<GlobalKeyboardHookEventArgs> handler = KeyboardPressed;
handler?.Invoke(this, eventArguments);
fEatKeyStroke = eventArguments.Handled;
}
return fEatKeyStroke ? (IntPtr)1 : CallNextHookEx(IntPtr.Zero, nCode, wParam, lParam);
}
}
}
根据的要求,我将发布我的修改版的答案。如果要检查我的更改,请搜索
//EDT
。我已经评论了大部分
设置
class GlobalKeyboardHookEventArgs : HandledEventArgs
{
public GlobalKeyboardHook.KeyboardState KeyboardState { get; private set; }
public GlobalKeyboardHook.LowLevelKeyboardInputEvent KeyboardData { get; private set; }
public GlobalKeyboardHookEventArgs(
GlobalKeyboardHook.LowLevelKeyboardInputEvent keyboardData,
GlobalKeyboardHook.KeyboardState keyboardState)
{
KeyboardData = keyboardData;
KeyboardState = keyboardState;
}
}
//Based on https://gist.github.com/Stasonix
class GlobalKeyboardHook : IDisposable
{
public event EventHandler<GlobalKeyboardHookEventArgs> KeyboardPressed;
// EDT: Added an optional parameter (registeredKeys) that accepts keys to restict
// the logging mechanism.
/// <summary>
///
/// </summary>
/// <param name="registeredKeys">Keys that should trigger logging. Pass null for full logging.</param>
public GlobalKeyboardHook(Keys[] registeredKeys = null)
{
RegisteredKeys = registeredKeys;
_windowsHookHandle = IntPtr.Zero;
_user32LibraryHandle = IntPtr.Zero;
_hookProc = LowLevelKeyboardProc; // we must keep alive _hookProc, because GC is not aware about SetWindowsHookEx behaviour.
_user32LibraryHandle = LoadLibrary("User32");
if (_user32LibraryHandle == IntPtr.Zero)
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to load library 'User32.dll'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_windowsHookHandle = SetWindowsHookEx(WH_KEYBOARD_LL, _hookProc, _user32LibraryHandle, 0);
if (_windowsHookHandle == IntPtr.Zero)
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to adjust keyboard hooks for '{Process.GetCurrentProcess().ProcessName}'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
// because we can unhook only in the same thread, not in garbage collector thread
if (_windowsHookHandle != IntPtr.Zero)
{
if (!UnhookWindowsHookEx(_windowsHookHandle))
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to remove keyboard hooks for '{Process.GetCurrentProcess().ProcessName}'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_windowsHookHandle = IntPtr.Zero;
// ReSharper disable once DelegateSubtraction
_hookProc -= LowLevelKeyboardProc;
}
}
if (_user32LibraryHandle != IntPtr.Zero)
{
if (!FreeLibrary(_user32LibraryHandle)) // reduces reference to library by 1.
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to unload library 'User32.dll'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_user32LibraryHandle = IntPtr.Zero;
}
}
~GlobalKeyboardHook()
{
Dispose(false);
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
private IntPtr _windowsHookHandle;
private IntPtr _user32LibraryHandle;
private HookProc _hookProc;
delegate IntPtr HookProc(int nCode, IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll")]
private static extern IntPtr LoadLibrary(string lpFileName);
[DllImport("kernel32.dll", CharSet = CharSet.Auto)]
private static extern bool FreeLibrary(IntPtr hModule);
/// <summary>
/// The SetWindowsHookEx function installs an application-defined hook procedure into a hook chain.
/// You would install a hook procedure to monitor the system for certain types of events. These events are
/// associated either with a specific thread or with all threads in the same desktop as the calling thread.
/// </summary>
/// <param name="idHook">hook type</param>
/// <param name="lpfn">hook procedure</param>
/// <param name="hMod">handle to application instance</param>
/// <param name="dwThreadId">thread identifier</param>
/// <returns>If the function succeeds, the return value is the handle to the hook procedure.</returns>
[DllImport("USER32", SetLastError = true)]
static extern IntPtr SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hMod, int dwThreadId);
/// <summary>
/// The UnhookWindowsHookEx function removes a hook procedure installed in a hook chain by the SetWindowsHookEx function.
/// </summary>
/// <param name="hhk">handle to hook procedure</param>
/// <returns>If the function succeeds, the return value is true.</returns>
[DllImport("USER32", SetLastError = true)]
public static extern bool UnhookWindowsHookEx(IntPtr hHook);
/// <summary>
/// The CallNextHookEx function passes the hook information to the next hook procedure in the current hook chain.
/// A hook procedure can call this function either before or after processing the hook information.
/// </summary>
/// <param name="hHook">handle to current hook</param>
/// <param name="code">hook code passed to hook procedure</param>
/// <param name="wParam">value passed to hook procedure</param>
/// <param name="lParam">value passed to hook procedure</param>
/// <returns>If the function succeeds, the return value is true.</returns>
[DllImport("USER32", SetLastError = true)]
static extern IntPtr CallNextHookEx(IntPtr hHook, int code, IntPtr wParam, IntPtr lParam);
[StructLayout(LayoutKind.Sequential)]
public struct LowLevelKeyboardInputEvent
{
/// <summary>
/// A virtual-key code. The code must be a value in the range 1 to 254.
/// </summary>
public int VirtualCode;
// EDT: added a conversion from VirtualCode to Keys.
/// <summary>
/// The VirtualCode converted to typeof(Keys) for higher usability.
/// </summary>
public Keys Key { get { return (Keys)VirtualCode; } }
/// <summary>
/// A hardware scan code for the key.
/// </summary>
public int HardwareScanCode;
/// <summary>
/// The extended-key flag, event-injected Flags, context code, and transition-state flag. This member is specified as follows. An application can use the following values to test the keystroke Flags. Testing LLKHF_INJECTED (bit 4) will tell you whether the event was injected. If it was, then testing LLKHF_LOWER_IL_INJECTED (bit 1) will tell you whether or not the event was injected from a process running at lower integrity level.
/// </summary>
public int Flags;
/// <summary>
/// The time stamp stamp for this message, equivalent to what GetMessageTime would return for this message.
/// </summary>
public int TimeStamp;
/// <summary>
/// Additional information associated with the message.
/// </summary>
public IntPtr AdditionalInformation;
}
public const int WH_KEYBOARD_LL = 13;
//const int HC_ACTION = 0;
public enum KeyboardState
{
KeyDown = 0x0100,
KeyUp = 0x0101,
SysKeyDown = 0x0104,
SysKeyUp = 0x0105
}
// EDT: Replaced VkSnapshot(int) with RegisteredKeys(Keys[])
public static Keys[] RegisteredKeys;
const int KfAltdown = 0x2000;
public const int LlkhfAltdown = (KfAltdown >> 8);
public IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam)
{
bool fEatKeyStroke = false;
var wparamTyped = wParam.ToInt32();
if (Enum.IsDefined(typeof(KeyboardState), wparamTyped))
{
object o = Marshal.PtrToStructure(lParam, typeof(LowLevelKeyboardInputEvent));
LowLevelKeyboardInputEvent p = (LowLevelKeyboardInputEvent)o;
var eventArguments = new GlobalKeyboardHookEventArgs(p, (KeyboardState)wparamTyped);
// EDT: Removed the comparison-logic from the usage-area so the user does not need to mess around with it.
// Either the incoming key has to be part of RegisteredKeys (see constructor on top) or RegisterdKeys
// has to be null for the event to get fired.
var key = (Keys)p.VirtualCode;
if (RegisteredKeys == null || RegisteredKeys.Contains(key))
{
EventHandler<GlobalKeyboardHookEventArgs> handler = KeyboardPressed;
handler?.Invoke(this, eventArguments);
fEatKeyStroke = eventArguments.Handled;
}
}
return fEatKeyStroke ? (IntPtr)1 : CallNextHookEx(IntPtr.Zero, nCode, wParam, lParam);
}
}
谢谢你的来信。尽管我简化了使用,但这段初始代码对我来说非常有用
private void buttonHook_Click(object sender, EventArgs e)
{
// Hooks only into specified Keys (here "A" and "B").
// (***) Use this constructor
_globalKeyboardHook = new GlobalKeyboardHook(new Keys[] { Keys.A, Keys.B });
// Hooks into all keys.
// (***) Or this - not both
_globalKeyboardHook = new GlobalKeyboardHook();
_globalKeyboardHook.KeyboardPressed += OnKeyPressed;
}
然后工作正常。我的代表太低,无法发表评论,但关于
CallbackOnCollectedDelegate
异常,我修改了C4d的答案中的public void SetupKeyboardHooks()
,如下所示:
public void SetupKeyboardHooks(out object hookProc)
{
_globalKeyboardHook = new GlobalKeyboardHook();
_globalKeyboardHook.KeyboardPressed += OnKeyPressed;
hookProc = _globalKeyboardHook.GcSafeHookProc;
}
其中,GcSafeHookProc
只是OPs中\u hookProc
的公共getter
_hookProc = LowLevelKeyboardProc; // we must keep alive _hookProc, because GC is not aware about SetWindowsHookEx behaviour.
并将
hookProc
存储为调用SetupKeyboardHooks(…)
的类中的私有字段,因此保持引用活动,从垃圾收集中保存,不再出现CallbackOnCollectedDelegate
异常。似乎在GlobalKeyboardHook
类中有此附加引用是不够的。可能要确保在关闭应用程序时也处理了此引用。您可以指定已经尝试过的模块。请看,这太棒了!您甚至可以捕获alt-F4并防止应用程序关闭。您甚至在示例中使用了C#6.0:)谢谢!我使用了这段代码,它可以工作。但是如果我在一段时间后按键,就会出现一个异常,表示委托被垃圾收集,托管代码应该让它保持活动状态。然后有一个空引用异常。你能帮我吗?我建议将公钥{get{return(Keys)VirtualCode;}}
添加到低层键盘输入事件
。这就需要处理虚拟代码,每个人都需要谷歌。另外:您可以将VkSnapshot
从int
更改为Keys
,然后轻松地放置一个键。我更进一步,放置了一个公共静态密钥[]RegisteredKeys
。如果(!GlobalKeyboardHook.RegisteredKeys.Contains(e.KeyboardData.Key))返回,则按下按钮将出现代码>。您当然可以防止触发事件;)@10年后的杜比?我不确定。但我明白了。一年过去了,在看了我的评论后,似乎有点难以理解。我将为今天晚上设置一个提醒。也许我会有一些时间来重建它。@dube hehe,这个问题已经有10年了。我已经在下面发布了我的修改版本。玩得开心!如何使用该类?有什么原因会返回奇数字符吗?@VAAA向您的解决方案中添加一个类。如果Program.cs中已有main(),请将此类中的main()重命名为InitializeComponent(),然后在project App()方法中调用它,例如SysTrayApp()。请参阅链接文章评论,了解Stephen回答的更多问题和回答。这将为您提供按下的原始键,如“S”,但是否有方法确定将插入哪个键,例如,如果caps lock关闭,则为“S”,但如果它打开,则为“S”?代码存在一些问题。首先,因为这是最后一个有XNA包装器的版本,而且我还写了一些旧的3D软件,所以我仍然使用VS2012来处理一些事情,包括这个。C#6运营者取代了我坐在那里准备尝试它。它不起作用,但我在VS2012中需要它,所以这可能是一个问题。我想我发现的问题在C#6中也是如此。GlobalKeyboardHook构造函数(如上)以:RegisteredKeys=RegisteredKeys开始;不幸的是,registeredKeys不会持久化,因此指向它的指针在返回时变得无效,并且在此后的所有调用中都为null。我的修复方法是在传入时检查它是否为null,在构造函数中创建一个大小相等的数组(静态和持久),并将传递的数组数据复制到其中)。非常感谢。非常感谢!这似乎失败后,一些按键?托管调试助手'CallbackOnCollectedDelegate'消息=托管调试助手'CallbackOnCollectedDelegate':'对'Keyboard'类型的垃圾收集委托进行了回调!键盘.GlobalKeyboardHook+HookProc::Invoke'。这可能会导致应用程序崩溃、损坏和数据丢失。将委托传递给非托管代码时,托管应用程序必须将其保持活动状态,直到保证永远不会调用它们为止。@C4d热键已被捕获,但在显示消息框后,我立即收到以下错误(以验证处理程序是否处于活动状态并正常工作):托管调试助手“CallbackOnCollectedDelegate”:“对类型为“GlobalKeyboardHook+HookProc::Invoke”的垃圾收集委托进行了回调。”。这可能会导致应用程序崩溃、损坏和数据丢失。将委托传递给非托管代码时,托管应用程序必须将其保持活动状态,直到保证永远不会调用它们为止。
如何解决此异常?^上述异常发生在LowLeveKeyboardProc()
底部的下一行:返回按键?(IntPtr)1:CallNextHookEx(IntPtr.Z
private void buttonHook_Click(object sender, EventArgs e)
{
// Hooks only into specified Keys (here "A" and "B").
// (***) Use this constructor
_globalKeyboardHook = new GlobalKeyboardHook(new Keys[] { Keys.A, Keys.B });
// Hooks into all keys.
// (***) Or this - not both
_globalKeyboardHook = new GlobalKeyboardHook();
_globalKeyboardHook.KeyboardPressed += OnKeyPressed;
}
public void SetupKeyboardHooks(out object hookProc)
{
_globalKeyboardHook = new GlobalKeyboardHook();
_globalKeyboardHook.KeyboardPressed += OnKeyPressed;
hookProc = _globalKeyboardHook.GcSafeHookProc;
}
_hookProc = LowLevelKeyboardProc; // we must keep alive _hookProc, because GC is not aware about SetWindowsHookEx behaviour.