namespace CairoObjective { public static class Set { public static void CheckContext() { if (Context == null) { throw new NullReferenceException("Context is Null. Set context on Set class."); } } public static Cairo.Context? Context; public static Cairo.Color Color = new Cairo.Color(1,1,1);//White #pragma warning disable CS8602 // Разыменование вероятной пустой ссылки. public static void Background(Cairo.Color color) { CheckContext(); var context = Set.Context; context.SetSourceColor(color); context.Paint(); } public static void Background() { CheckContext(); var context = Set.Context; context.SetSourceColor(Color); context.Paint(); } } }