private static int HookCallback(int code, IntPtr wParam, ref NativeHook.KBDLLHOOKSTRUCT lParam)
{
if (code < 0)
{
return(NativeHook.CallNextHookEx(IntPtr.Zero, code, wParam, ref lParam));
}
KeyboardHookEventArgs.EventType evtType;
switch ((NativeHook.WmKeyUpDown)wParam.ToInt32())
{
case NativeHook.WmKeyUpDown.WM_KEYDOWN:
case NativeHook.WmKeyUpDown.WM_SYSKEYDOWN:
evtType = KeyboardHookEventArgs.EventType.KeyDown;
break;
case NativeHook.WmKeyUpDown.WM_KEYUP:
case NativeHook.WmKeyUpDown.WM_SYSKEYUP:
evtType = KeyboardHookEventArgs.EventType.KeyUp;
break;
default:
Trace.TraceWarning($"Received unexpected WM_KEYXXXX ({wParam.ToInt32()}) in HookCallback");
return(NativeHook.CallNextHookEx(IntPtr.Zero, code, wParam, ref lParam));
}
var evt = new KeyboardHookEventArgs(KeyInterop.KeyFromVirtualKey(lParam.vkCode), evtType);
KeyboardHookCalled?.Invoke(null, evt);
return(evt.Handled ? 1 : NativeHook.CallNextHookEx(IntPtr.Zero, code, wParam, ref lParam));
}
public static void DisableKeyboardHook()
{
if (_currentHook != IntPtr.Zero)
{
NativeHook.UnhookWindowsHookEx(_currentHook);
_currentHook = IntPtr.Zero;
}
}
public static void ActivateKeyboardHook()
{
if (_currentHook != IntPtr.Zero)
{
throw new Exception("LL Keyboard Hook already set.");
}
#pragma warning disable CS0618 // Type or member is obsolete
_currentHook = NativeHook.SetWindowsHookExA(NativeHook.HookType.WH_KEYBOARD_LL, _hookFunction, IntPtr.Zero, 0);
#pragma warning restore CS0618 // Type or member is obsolete
if (_currentHook == IntPtr.Zero)
{
int res = Marshal.GetLastWin32Error();
throw new Exception($"Error setting up LL Hook: {res}");
}
}
private static void Main(string[] args)
{
// Managed hook example.
MethodBase writeLineMethod = "System.Console".GetMethod("WriteLine", new[] { typeof(string) }, BindingFlags.Static | BindingFlags.Public);
MethodBase replacementMethod = "DotNetHook.Program".GetMethod("WriteLineReplacement", BindingFlags.Static | BindingFlags.NonPublic);
_managedHook = new ManagedHook(writeLineMethod, replacementMethod);
Console.WriteLine("Before Hook");
// Apply the hook.
_managedHook.Apply();
// Call the method we hooked.
Console.WriteLine("Modified Hello");
// Remove the hook, alternatively you can use a "using" statement to dispose of the hook.
_managedHook.Remove();
Console.WriteLine("After Hook");
Console.ReadLine();
// Native hook example.
MethodBase nativeReplacementMethod = "DotNetHook.Program".GetMethod("MessageBoxReplacement", BindingFlags.Static | BindingFlags.NonPublic);
_nativeHook = new NativeHook(new NativeMethod("MessageBoxA", "user32.dll"), nativeReplacementMethod);
MessageBoxA(IntPtr.Zero, "Before Hook", "The title!", 0);
// Apply the hook.
_nativeHook.Apply();
// Call the method hooked.
MessageBoxA(IntPtr.Zero, "Modified Hello", "The title!", 0);
// Remove the hook, alternatively you can use a "using" statement to dispose of the hook.
_nativeHook.Remove();
MessageBoxA(IntPtr.Zero, "After Hook", "The title!", 0);
}