我正在嘗試替換基類中的派生實(shí)例。它適用于動(dòng)物（抽象類的簡單用法），但不適用于泛型。錯(cuò)誤在SomeMethod. 有沒有干凈的解決方案？編輯：在另一個(gè)界面的幫助下，它確實(shí)是可行的。用 [S] 注釋的代碼是我原來問題的解決方案。public abstract class Animal{    public void Feed()    {    }}public class Tiger:Animal{}public class Dog : Animal{}public class Consumer{    public Tiger Tiger { get; set; }    public Dog Dog { get; set; }    public Animal FavoriteAnimal { get; set; }    void SomeMethod()    {        // This is fine        FavoriteAnimal = Tiger;        FavoriteAnimal = Dog;        FavoriteAnimal.Feed();        //Also fine         int numberOfDogs = PlaceForDogs.CountAnimals();        int numberOfTigers = PlaceForTigers.CountAnimals();        //[S] This is doable now        FavoritePlaceForAnimals = PlaceForDogs;//[S]  no more ERROR        int numberOfAnimalsOnMyFavoritPlace = FavoritePlaceForAnimals.CountAnimals(); // No error, but I do not get here...    }    public PlaceForDogs PlaceForDogs { get; set; } = new PlaceForDogs();    public PlaceForTigers PlaceForTigers { get; set; } = new PlaceForTigers();    //public PlaceForAnimals<Animal> FavoritePlaceForAnimals { get; set; }    //[S] favorite place is of type IPlaceForAnimals instead of PlaceForAnimals    public IPlaceForAnimals FavoritePlaceForAnimals { get; set; }}//[S]new interfacepublic interface IPlaceForAnimals{    int CountAnimals();}//[S]abstract class implements the interfacepublic abstract class PlaceForAnimals<T>:IPlaceForAnimals  where T : Animal{    public List<T> Animals { get; set; }    public int CountAnimals()    {        //special counting using properties from Animal class        return 0;    }}