Lluís Franco on Geeks.ms

   1: using System;

   2: using System.Runtime.InteropServices;

   3: using System.Windows.Forms;

   4:  

   5: namespace TestRegisterHotKey

   6: {

   7:     public class WindowsShell

   8:     {

   9:         public enum ModifierEnum

  10:         {

  11:             MOD_ALT = 0x1,

  12:             MOD_CONTROL = 0x2,

  13:             MOD_SHIFT = 0x4,

  14:             MOD_WIN = 0x8

  15:         }

  16:  

  17:         private static int keyId;

  18:         public static int WM_HOTKEY = 0x312;

  19:  

  20:         [DllImport("user32.dll")]

  21:         private static extern bool RegisterHotKey(

  22:             IntPtr hWnd, int id, int fsModifiers, int vlc);

  23:  

  24:         [DllImport("user32.dll")]

  25:         private static extern bool UnregisterHotKey(

  26:             IntPtr hWnd, int id);

  27:  

  28:         public static void RegisterHotKey(Form f, Keys key)

  29:         {

  30:             int modifiers = 0;

  31:             if ((key & Keys.Alt) == Keys.Alt)

  32:                 modifiers = modifiers | (int)WindowsShell.ModifierEnum.MOD_ALT;

  33:             if ((key & Keys.Control) == Keys.Control)

  34:                 modifiers = modifiers | (int)WindowsShell.ModifierEnum.MOD_CONTROL;

  35:             if ((key & Keys.Shift) == Keys.Shift)

  36:                 modifiers = modifiers | (int)WindowsShell.ModifierEnum.MOD_SHIFT;

  37:             Keys k = key & ~Keys.Control & ~Keys.Shift & ~Keys.Alt;

  38:             f.Invoke(new Action(() =>

  39:             {

  40:                 keyId = f.GetHashCode();

  41:                 RegisterHotKey((IntPtr)f.Handle, keyId, modifiers, (int)k);

  42:             }));

  43:         }

  44:  

  45:         public static void UnregisterHotKey(Form f)

  46:         {

  47:             try

  48:             {

  49:                 f.Invoke(new Action(() =>

  50:                 {

  51:                     UnregisterHotKey(f.Handle, keyId);

  52:                 }));

  53:             }

  54:             catch (Exception)

  55:             {

  56:                 throw;

  57:             }

  58:         }

  59:  

  60:     }

  61: }

   1: using System;

   2: using System.Windows.Forms;

   3:  

   4: namespace TestRegisterHotKey

   5: {

   6:     public partial class Form1 : Form

   7:     {        

   8:         public Form1()

   9:         {

  10:             InitializeComponent();

  11:             this.Shown += Form1_Shown;

  12:             this.FormClosed += Form1_FormClosed;

  13:         }

  14:  

  15:         void Form1_FormClosed(object sender, FormClosedEventArgs e)

  16:         {

  17:             WindowsShell.UnregisterHotKey(this);

  18:         }

  19:  

  20:         void Form1_Shown(object sender, EventArgs e)

  21:         {

  22:             Keys k = Keys.A | Keys.Control;

  23:             WindowsShell.RegisterHotKey(this, k);

  24:         }

  25:  

  26:         protected override void WndProc(ref Message m)

  27:         {

  28:             if (m.Msg == WindowsShell.WM_HOTKEY)

  29:             {

  30:                 Keys key = (Keys)(((int)m.LParam >> 16) & 0xFFFF);

  31:                 WindowsShell.ModifierEnum modifier = 

  32:                     (WindowsShell.ModifierEnum)((int)m.LParam & 0xFFFF);

  33:                 if (key == Keys.A && modifier == WindowsShell.ModifierEnum.MOD_CONTROL)

  34:                     showForm();

  35:             }

  36:             base.WndProc(ref m);

  37:         }

  38:  

  39:         private void showForm()

  40:         {

  41:             this.Text = 

  42:                 String.Format("Hokey pressed at: {0}", 

  43:                 DateTime.Now.ToLongTimeString());

  44:             this.Show();

  45:             if (this.WindowState == FormWindowState.Minimized)

  46:                 this.WindowState = FormWindowState.Normal;

  47:         }

  48:     }

  49: }