copy_string.cs

class copy_string : Callable
{
    public override uint Call32from16(Machine machine, bool hook, bool dlgproc, ref Win16.MSG msg16, ref Win32.MSG msg32, Func<IntPtr> callback)
    {
        unsafe
        {
            var str = machine.ReadString(msg16.lParam);
            fixed (char* psz = str)
            {
                msg32.wParam = (IntPtr)msg16.wParam;
                msg32.lParam = (IntPtr)psz;
                return (uint)(callback());
            }
        }
    }

    public override IntPtr Call16from32(Machine machine, bool hook, bool dlgproc, ref Win32.MSG msg32, ref Win16.MSG msg16, Func<uint> callback)
    {
        // Get the string
        string text = null;
        if (msg32.lParam != IntPtr.Zero)
        {
            text = Marshal.PtrToStringUni(msg32.lParam);
        }

        // Allocate string
        var ptr = machine.SysAllocString(text);
        msg16.wParam = msg32.wParam.Loword();
        msg16.lParam = ptr;
        
        // Call 
        var retv = callback();
        
        // Cleanup
        machine.SysFree(ptr);

        return (IntPtr)retv;
    }
}