[C#] Catching every multiple Keys

The solution is using PreviewKeyDown event.

Example:

private void OnPreviewKeyDown( object sender, PreviewKeyDownEventArgs e)
{
    if (e.Control && e.Shift && e.Alt && e.KeyCode = Keys.A);
    {
        MessageBox.Show("You've pressed Ctrl + Shift + Alt + A");        // Write your code here.
    }