C# Signature:

[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool RegisterHotKey(IntPtr hWnd, int id, uint fsModifiers,
   uint vk);

VB Signature:

<DllImport("user32.dll")> _
Public Shared Function RegisterHotKey(ByVal hWnd As IntPtr, ByVal id As Integer, _
    ByVal fsModifier As Integer, ByVal vk As Integer) As Integer
End Function

VB.net Signature:

Declare Auto Function registerhotkey Lib "user32.dll" (ByVal id As Integer, ByVal fsModifier As Integer, ByVal vk As Integer) As Integer

User-Defined Types:

None.

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

    // c#
    public class WindowsShell
    {
        #region fields
        public static int MOD_ALT = 0x1;
        public static int MOD_CONTROL = 0x2;
        public static int MOD_SHIFT = 0x4;
        public static int MOD_WIN = 0x8;
        public static int WM_HOTKEY = 0x312;
        #endregion

        [DllImport("user32.dll")]
        private static extern bool RegisterHotKey(IntPtr hWnd, int id, int fsModifiers, int vlc);

        [DllImport("user32.dll")]
        private static extern bool UnregisterHotKey(IntPtr hWnd, int id);

        private static int keyId;
        public static void RegisterHotKey(Form f, Keys key)
        {
            int modifiers = 0;

            if ((key & Keys.Alt) == Keys.Alt)
                modifiers = modifiers | WindowsShell.MOD_ALT;

            if ((key & Keys.Control) == Keys.Control)
                modifiers = modifiers | WindowsShell.MOD_CONTROL;

            if ((key & Keys.Shift) == Keys.Shift)
                modifiers = modifiers | WindowsShell.MOD_SHIFT;

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

            Func ff = delegate()
                {
                    keyId = f.GetHashCode(); // this should be a key unique ID, modify this if you want more than one hotkey
                    RegisterHotKey((IntPtr)f.Handle, keyId, modifiers, (int)k);
                };

            f.Invoke(ff); // this should be checked if we really need it (InvokeRequired), but it's faster this way
        }

        private delegate void Func();

        public static void UnregisterHotKey(Form f)
        {
            try
            {
                Func ff = delegate()
                {
                    UnregisterHotKey(f.Handle, keyId); // modify this if you want more than one hotkey
                };

                f.Invoke(ff); // this should be checked if we really need it (InvokeRequired), but it's faster this way
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.ToString());
            }
        }
    }

    public partial class Form1 : Form, IDisposable
    {
        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);
            Keys k = Keys.A | Keys.Control;
            WindowsShell.RegisterHotKey(this, k);
        }

        // CF Note: The WndProc is not present in the Compact Framework (as of vers. 3.5)! please derive from the MessageWindow class in order to handle WM_HOTKEY
        protected override void WndProc(ref Message m)
        {
            base.WndProc(ref m);

            if (m.Msg == WindowsShell.WM_HOTKEY)
                this.Visible = !this.Visible;
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            WindowsShell.UnregisterHotKey(this);
        }
    }

Alternative Managed API:

The ManagedWindowsApi project (http://mwinapi.sourceforge.net) provides a

Hotkey class to register global hotkeys.

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