public void TestMethod1() { var products = new List <Product> { new Product { Name = "01", Amount = 10, Actived = false, Category = new Category { Actived = false } }, new Product { Name = "02", Amount = 11, Actived = false, Category = new Category { Actived = false } }, new Product { Name = "03", Amount = 8, Actived = true, Category = new Category { Actived = true } }, new Product { Name = "04", Amount = 5, Actived = true, Category = new Category { Actived = true } }, new Product { Name = "05", Amount = 4, Actived = false, Category = new Category { Actived = true } } }; var productQuery = new ProductQuery(); foreach (var product in productQuery.ExecuteQuery(products.AsQueryable()).ToList()) { Console.WriteLine(product.Name); } }