当我不需要条形码扫描仪时,我正尝试禁用它。我有活动的键盘和条形码扫描仪(我们可以称其为另一个键盘)。我设法在KEYDOWN和KEYUP事件上获取键,并设置e.Handled = true以禁用特定键。现在,我需要一些帮助来禁用特定设备上的所有按键。
我正在从这两篇文章中研究代码: https://stackoverflow.com/a/34384189/4183512 https://www.codeproject.com/Articles/17123/Using-Raw-Input-from-C-to-handle-multiple-keyboard
我设法从第二篇文章中找到哪种设备的密钥,并在第一篇文章中禁用了特定的密钥,但不知道如何从第二篇文章到第一篇文章中实现设备识别。
这是我到目前为止所拥有的:
从第一个链接中获取课程
Router
CODEBEHIND
namespace DisableBarcode
{
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);
}
}
}
我可能还需要在“结构LowLevelKeyboardInputEvent”中添加内容以获取设备信息,但是不知道如何。
预先感谢您的帮助!