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December 26, 2016 22:43
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using System; | |
using System.Collections.Generic; | |
using System.Linq; | |
using System.Runtime.InteropServices; | |
using System.Text; | |
using System.Windows.Forms; | |
namespace Utils | |
{ | |
public sealed class KeyboardHook : IDisposable | |
{ | |
// Registers a hot key with Windows. | |
[DllImport("user32.dll")] | |
private static extern bool RegisterHotKey(IntPtr hWnd, int id, uint fsModifiers, uint vk); | |
// Unregisters the hot key with Windows. | |
[DllImport("user32.dll")] | |
private static extern bool UnregisterHotKey(IntPtr hWnd, int id); | |
public event EventHandler<KeyPressedEventArgs> KeyPressed; | |
public event EventHandler<KeyPressedEventArgs> KeyRelease; | |
/// <summary> | |
/// Represents the window that is used internally to get the messages. | |
/// </summary> | |
private class Window : NativeWindow, IDisposable | |
{ | |
private const int WM_HOTKEY = 0x0312; | |
private const int WM_KEYDOWN = 0x0100; | |
private const int WM_KEYUP = 0x0101; | |
private const int WM_SYSKEYDOWN = 0x0104; | |
private const int WM_SYSKEYUP = 0x0105; | |
public event EventHandler<KeyPressedEventArgs> KeyPressed; | |
public event EventHandler<KeyPressedEventArgs> KeyRelease; | |
public Window() | |
{ | |
// create the handle for the window. | |
this.CreateHandle(new CreateParams()); | |
} | |
/// <summary> | |
/// Overridden to get the notifications. | |
/// </summary> | |
/// <param name="m"></param> | |
protected override void WndProc(ref Message m) | |
{ | |
base.WndProc(ref m); | |
// check if we got a hot key pressed. | |
if (m.Msg == WM_HOTKEY) | |
{ | |
// get the keys. | |
Keys key = (Keys)(((int)m.LParam >> 16) & 0xFFFF); | |
ModifierKeys modifier = (ModifierKeys)((int)m.LParam & 0xFFFF); | |
KeyPressed?.Invoke(this, new KeyPressedEventArgs(modifier, key)); | |
// TODO: KeyRelease?.Invoke(this, new KeyPressedEventArgs(modifier, key)); | |
} | |
} | |
#region IDisposable Members | |
public void Dispose() | |
{ | |
this.DestroyHandle(); | |
} | |
#endregion | |
} | |
private Window _window = new Window(); | |
private int _currentId; | |
public KeyboardHook() | |
{ | |
// register the event of the inner native window. | |
_window.KeyPressed += delegate (object sender, KeyPressedEventArgs args) | |
{ | |
KeyPressed?.Invoke(this, args); | |
}; | |
_window.KeyRelease += delegate (object sender, KeyPressedEventArgs args) | |
{ | |
KeyRelease?.Invoke(this, args); | |
}; | |
} | |
/// <summary> | |
/// Registers a hot key in the system. | |
/// </summary> | |
/// <param name="modifier">The modifiers that are associated with the hot key.</param> | |
/// <param name="key">The key itself that is associated with the hot key.</param> | |
public void RegisterHotKey(ModifierKeys modifier, Keys key) | |
{ | |
// increment the counter. | |
_currentId = _currentId + 1; | |
// register the hot key. | |
if (!RegisterHotKey(_window.Handle, _currentId, (uint)modifier, (uint)key)) | |
throw new InvalidOperationException("Couldn’t register the hot key."); | |
} | |
#region IDisposable Members | |
public void Dispose() | |
{ | |
// unregister all the registered hot keys. | |
for (int i = _currentId; i > 0; i--) | |
{ | |
UnregisterHotKey(_window.Handle, i); | |
} | |
// dispose the inner native window. | |
_window.Dispose(); | |
} | |
#endregion | |
} | |
/// <summary> | |
/// Event Args for the event that is fired after the hot key has been pressed. | |
/// </summary> | |
public class KeyPressedEventArgs : EventArgs | |
{ | |
private ModifierKeys _modifier; | |
private Keys _key; | |
internal KeyPressedEventArgs(ModifierKeys modifier, Keys key) | |
{ | |
_modifier = modifier; | |
_key = key; | |
} | |
public ModifierKeys Modifier | |
{ | |
get { return _modifier; } | |
} | |
public Keys Key | |
{ | |
get { return _key; } | |
} | |
} | |
/// <summary> | |
/// The enumeration of possible modifiers. | |
/// </summary> | |
[Flags] | |
public enum ModifierKeys : uint | |
{ | |
None = 0, | |
Alt = 1, | |
Control = 2, | |
Shift = 4, | |
Win = 8 | |
} | |
} |
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