internal static WindowClass Create(string className, User32.CS classStyle)
{
lock (s_wcInternalSyncObject)
{
WindowClass wc = s_cache;
if (className is null)
{
// If we weren't given a class name, look for a window
// that has the exact class style.
while (wc != null &&
(wc._className != null || wc._classStyle != classStyle))
{
wc = wc._next;
}
}
else
{
while (wc != null && !className.Equals(wc._className))
{
wc = wc._next;
}
}
if (wc is null)
{
// Didn't find an existing class, create one and attatch it to
// the end of the linked list.
wc = new WindowClass(className, classStyle)
{
_next = s_cache
};
s_cache = wc;
}
return(wc);
}
}
/// <summary>
/// Constructor.
/// </summary>
/// <param name="className">Name, or default will be generated.</param>
/// <param name="moduleInstance">Module to associate with the window. The entry assembly is the default.</param>
/// <param name="backgroundBrush">Use (IntPtr)(-1) for no background brush.</param>
/// <param name="icon">Use (IntPtr)(-1) for no icon.</param>
/// <param name="cursor">Use (IntPtr)(-1) for no cursor.</param>
/// <param name="menuName">Menu name, can not set with <paramref name="menuId"/>.</param>
/// <param name="menuId">Menu id, can not set with <paramref name="menuName"/>.</param>
public unsafe WindowClass(
string className = default,
IntPtr moduleInstance = default,
User32.CS classStyle = User32.CS.HREDRAW | User32.CS.VREDRAW,
IntPtr backgroundBrush = default,
IntPtr icon = default,
IntPtr cursor = default,
string menuName = null,
int menuId = 0,
int classExtraBytes = 0,
int windowExtraBytes = 0)
{
// Handle default values
className ??= Guid.NewGuid().ToString();
if (backgroundBrush == default)
{
backgroundBrush = User32.GetSysColorBrush(COLOR_WINDOW);
}
else if (backgroundBrush == (IntPtr)(-1))
{
backgroundBrush = default;
}
if (icon == default)
{
icon = LoadIconW(IntPtr.Zero, (IntPtr)IDI_APPLICATION);
}
else if (icon == (IntPtr)(-1))
{
icon = default;
}
if (cursor == default)
{
cursor = User32.LoadCursorW(IntPtr.Zero, (IntPtr)User32.CursorResourceId.IDC_ARROW);
}
else if (cursor == (IntPtr)(-1))
{
cursor = default;
}
if (moduleInstance == IntPtr.Zero)
{
Marshal.GetHINSTANCE(Assembly.GetCallingAssembly().Modules.First());
}
if (menuId != 0 && menuName != null)
{
throw new ArgumentException($"Can't set both {nameof(menuName)} and {nameof(menuId)}.");
}
_windowProcedure = WNDPROC;
ModuleInstance = moduleInstance;
_className = className;
_menuName = menuName ?? string.Empty;
_wndClass = new User32.WNDCLASS
{
style = classStyle,
lpfnWndProc = Marshal.GetFunctionPointerForDelegate(_windowProcedure),
cbClsExtra = classExtraBytes,
cbWndExtra = windowExtraBytes,
hInstance = moduleInstance,
hIcon = icon,
hCursor = cursor,
hbrBackground = backgroundBrush,
lpszMenuName = (char *)menuId
};
}
internal WindowClass(string className, User32.CS classStyle)
{
_className = className;
_classStyle = classStyle;
RegisterClass();
}
