Question

My Solution

[DllImport("user32.dll")]
public static extern bool RegisterHotKey(IntPtr hWnd, int id, uint fsModifiers, int vk);
[DllImport("user32.dll")]
public static extern bool UnregisterHotKey(IntPtr hWnd, int id);
public enum KeyModifiers : uint { None = 0, Alt = 1, Control = 2, Shift = 4, Windows = 8, }
Actions<int, string> Directories = new Dictionary<int, string>();
const string MessageTitle = "Opps, Somthing Happened!";
const MessageBoxButtons msgButtons = MessageBoxButtons.OK;
const MessageBoxIcon msgIcon = MessageBoxIcon.Information;

private void btnCreateShortcut_Click(object sender, EventArgs e)
{
    if (cboModifier.SelectedIndex > 0)
    {
        uint key = (uint)Enum.Parse(typeof(KeyModifiers), cboModifier.SelectedItem.ToString());
        if (txtShortcutKey.Text != "")
            CreateHotKey(key, txtShortcutKey.Text.ToString());
        else
            MessageBox.Show("Please enter a Hot key to use", MessageTitle, msgButtons, msgIcon);
    }
    else
        MessageBox.Show("Please Select a Base Key", MessageTitle, msgButtons, msgIcon);
}

private void btnDestroyShortcuts_Click(object sender, EventArgs e)
{
    destroyShortcuts();
}

private void quickActions_FormClosing(object sender, FormClosingEventArgs e)
{
    destroyShortcuts();
}

protected override void WndProc(ref Message msg)
{
    switch (msg.Msg)
    {
        case 0x0312:
            if (Actions.ContainsKey((int)msg.WParam))
                // Preform Action
            break;
    }
    base.WndProc(ref msg);
}


public void destroyShortcuts()
{
    foreach (KeyValuePair<int, string> pair in Actions)
        UnregisterHotKey(this.Handle, pair.Key);

    lstActiveKeys.Items.Clear();
    Actions.Clear();
}

public void CreateHotKey(uint modifier, string key)
{
    int keyID = (Actions.Count + 1) * 100;
    Actions.Add(keyID, txtAction.Text.ToString());
    lstActiveKeys.Items.Add(modifier + "+" + key[0] + " - " + txtAction.Text.ToString());
    RegisterHotKey(this.Handle, keyID, modifier, (int)((char)key[0]));
}

I would like to know how to make it so that my users could define their own hot keys given the options for select a control key and a letter.

All of the code I found showed how to define one single hot key, but one users could have 3 and another could have 5 and they may not be the same keys.

What I would like, is given a control key and a alphanumeric key I can create a Windows Hot Key.

I also need to be able to destroy the registered keys when the application is closed.

PS: These needs to be system-wide not just within the application. Thanks @scott-chapman for pointing that out

Answer 1

Here is the solution I developed this is a C# method that appears to be working rather nicely.

[DllImport("user32.dll")]
public static extern bool RegisterHotKey(IntPtr hWnd, int id, uint fsModifiers, int vk);
[DllImport("user32.dll")]
public static extern bool UnregisterHotKey(IntPtr hWnd, int id);
public enum KeyModifiers : uint { None = 0, Alt = 1, Control = 2, Shift = 4, Windows = 8, }
Actions<int, string> Directories = new Dictionary<int, string>();
const string MessageTitle = "Opps, Somthing Happened!";
const MessageBoxButtons msgButtons = MessageBoxButtons.OK;
const MessageBoxIcon msgIcon = MessageBoxIcon.Information;

private void btnCreateShortcut_Click(object sender, EventArgs e)
{
    if (cboModifier.SelectedIndex > 0)
    {
        uint key = (uint)Enum.Parse(typeof(KeyModifiers), cboModifier.SelectedItem.ToString());
        if (txtShortcutKey.Text != "")
            CreateHotKey(key, txtShortcutKey.Text.ToString());
        else
            MessageBox.Show("Please enter a Hot key to use", MessageTitle, msgButtons, msgIcon);
    }
    else
        MessageBox.Show("Please Select a Base Key", MessageTitle, msgButtons, msgIcon);
}

private void btnDestroyShortcuts_Click(object sender, EventArgs e)
{
    destroyShortcuts();
}

private void quickActions_FormClosing(object sender, FormClosingEventArgs e)
{
    destroyShortcuts();
}

protected override void WndProc(ref Message msg)
{
    switch (msg.Msg)
    {
        case 0x0312:
            if (Actions.ContainsKey((int)msg.WParam))
                // Preform Action
            break;
    }
    base.WndProc(ref msg);
}


public void destroyShortcuts()
{
    foreach (KeyValuePair<int, string> pair in Actions)
        UnregisterHotKey(this.Handle, pair.Key);

    lstActiveKeys.Items.Clear();
    Actions.Clear();
}

public void CreateHotKey(uint modifier, string key)
{
    int keyID = (Actions.Count + 1) * 100;
    Actions.Add(keyID, txtAction.Text.ToString());
    lstActiveKeys.Items.Add(modifier + "+" + key[0] + " - " + txtAction.Text.ToString());
    RegisterHotKey(this.Handle, keyID, modifier, (int)((char)key[0]));
}