確認コード byte[] buff = new byte[256]; int r = SendMessageA(hnd, WM_GETTEXT, 100, buff); int r = SendMessageW(hnd, WM_GETTEXT, 100, buff); [DllImport("user32.dll")] public static extern int SendMessageA(IntPtr hWnd, int Msg, int wParam, byte[] lParam); [DllImport("user32.dll")] public static extern int SendMessageW(IntPtr hWnd, int Msg, int wParam, byte[] lParam);