C# (CSharp) CityViewModel.Remove示例

        public void RemoveTest()
        {
            CityViewModel cityViewModel = new CityViewModel();

            cityViewModel.Cities.Add(new City("NewYork"));
            cityViewModel.Cities.Add(new City("Saratov"));

            bool isTwoCity = cityViewModel.Cities.Count() == 2;

            cityViewModel.SelectedItem = cityViewModel.Cities.FirstOrDefault(c => string.Equals(c.Name, "NewYork"));

            if (cityViewModel.SelectedItem != null)
            {
                cityViewModel.Remove(cityViewModel.SelectedItem);
            }

            bool isNoNewYork = cityViewModel.Cities.FirstOrDefault(c => string.Equals(c.Name, "NewYork")) == null;

            bool isOneCity = cityViewModel.Cities.Count() == 1;

            cityViewModel.SelectedItem = null;
            City.AllCities.Clear();

            Assert.IsTrue(isTwoCity && isNoNewYork && isOneCity);
        }