public static void ShowHelp(Control control, string message)
{
HH_POPUP popup = new HH_POPUP(Marshal.StringToCoTaskMemUni(message));
try
{
if (GetCursorPos(out popup.pt))
{
RECT WindowBounds;
HandleRef Parent = new HandleRef(control, control.Handle);
if (GetWindowRect(Parent, out WindowBounds))
{
if (!WindowBounds.Contains(popup.pt))
{
#warning TODO: proper alignment if partially off the screen
popup.pt.X = WindowBounds.Left + ((WindowBounds.Right - WindowBounds.Left) >> 1);
popup.pt.Y = WindowBounds.Top + ((WindowBounds.Bottom - WindowBounds.Top) >> 1);
}
HtmlHelpW(Parent, IntPtr.Zero, HH_DISPLAY_TEXT_POPUP, ref popup); // file parameter must be null
}
}
}
finally
{
Marshal.FreeCoTaskMem(popup.pszText);
}
}
private static extern IntPtr HtmlHelpW(HandleRef control, IntPtr file, uint command, [In] ref HH_POPUP popup);