You need to get a hook into the win32 api. As soon as you hide your .net form, the events and event subscribers stop working because they only exist in the container of the form. You need something like this.
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Windows.Input;
public class GlobalHotKey : IDisposable
{
public static bool RegisterHotKey(string aKeyGestureString, Action aAction)
{
var c = new KeyGestureConverter();
KeyGesture aKeyGesture = (KeyGesture)c.ConvertFrom(aKeyGestureString);
return RegisterHotKey(aKeyGesture.Modifiers, aKeyGesture.Key, aAction);
}
public static bool RegisterHotKey(ModifierKeys aModifier, Key aKey, Action aAction)
{
if (aModifier == ModifierKeys.None)
{
throw new ArgumentException("Modifier must not be ModifierKeys.None");
}
if (aAction is null)
{
throw new ArgumentNullException(nameof(aAction));
}
System.Windows.Forms.Keys aVirtualKeyCode = (System.Windows.Forms.Keys)KeyInterop.VirtualKeyFromKey(aKey);
currentID = currentID + 1;
bool aRegistered = RegisterHotKey(window.Handle, currentID,
(uint)aModifier | MOD_NOREPEAT,
(uint)aVirtualKeyCode);
if (aRegistered)
{
registeredHotKeys.Add(new HotKeyWithAction(aModifier, aKey, aAction));
}
return aRegistered;
}
public void Dispose()
{
for (int i = currentID; i > 0; i--)
{
UnregisterHotKey(window.Handle, i);
}
window.Dispose();
}
static GlobalHotKey()
{
window.KeyPressed += (s, e) =>
{
registeredHotKeys.ForEach(x =>
{
if (e.Modifier == x.Modifier && e.Key == x.Key)
{
x.Action();
}
});
};
}
private static readonly InvisibleWindowForMessages window = new InvisibleWindowForMessages();
private static int currentID;
private static uint MOD_NOREPEAT = 0x4000;
private static List<HotKeyWithAction> registeredHotKeys = new List<HotKeyWithAction>();
private class HotKeyWithAction
{
public HotKeyWithAction(ModifierKeys modifier, Key key, Action action)
{
Modifier = modifier;
Key = key;
Action = action;
}
public ModifierKeys Modifier { get; }
public Key Key { get; }
public Action Action { get; }
}
[DllImport("user32.dll")]
private static extern bool RegisterHotKey(IntPtr hWnd, int id, uint fsModifiers, uint vk);
[DllImport("user32.dll")]
private static extern bool UnregisterHotKey(IntPtr hWnd, int id);
private class InvisibleWindowForMessages : System.Windows.Forms.NativeWindow, IDisposable
{
public InvisibleWindowForMessages()
{
CreateHandle(new System.Windows.Forms.CreateParams());
}
private static int WM_HOTKEY = 0x0312;
protected override void WndProc(ref System.Windows.Forms.Message m)
{
base.WndProc(ref m);
if (m.Msg == WM_HOTKEY)
{
var aWPFKey = KeyInterop.KeyFromVirtualKey(((int)m.LParam >> 16) & 0xFFFF);
ModifierKeys modifier = (ModifierKeys)((int)m.LParam & 0xFFFF);
if (KeyPressed != null)
{
KeyPressed(this, new HotKeyPressedEventArgs(modifier, aWPFKey));
}
}
}
public class HotKeyPressedEventArgs : EventArgs
{
private ModifierKeys _modifier;
private Key _key;
internal HotKeyPressedEventArgs(ModifierKeys modifier, Key key)
{
_modifier = modifier;
_key = key;
}
public ModifierKeys Modifier
{
get { return _modifier; }
}
public Key Key
{
get { return _key; }
}
}
public event EventHandler<HotKeyPressedEventArgs> KeyPressed;
#region IDisposable Members
public void Dispose()
{
this.DestroyHandle();
}
#endregion
}
}
Now register S and H with Alt + Shift by calling and passing in a call back of type
Action
.
RegisterHoitKey
.
Wire up an Action for your call back that will show your form or hide it.