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.
