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Accepted
Iván Rodríguez
Asked: 2022-03-29 05:53:25 +0800 CST 2022-03-29 05:53:25 +0800 CST

what is the syntax to cast a generic class? C#

  • 772

How do you do a casting of a geric class?

I am trying the following but it doesn't work. This is the error that is giving me

CS0119 C# 'Entity' is type, which is not valid in the given context

//-----------------------------------------------------------------
//DataBase: Es un tipo génerico
public class Entity<DataBase> : MonoBehaviour where DataBase : class
{
    [SerializeField] private DataBase dataBase;
}
//-----------------------------------------------------------------
//EnemyDataBase: Es un tipo específico
public class Enemy : Entity<EnemyDataBase>
{
    EnemyDataBase enemyDataBase;
}
//-----------------------------------------------------------------
//DataBase: Es un tipo génerico
public class State <DataBase> where DataBase : class
{
   protected Entity<DataBase> entity;

   Public method(Entity<DataBase> entity)
   {
   }
}
//-----------------------------------------------------------------
public class MyEnemy : Enemy
{
   State state;
   Public void Start()
   {
         state = new State();

         state.method( Entity<EnemyDataBase> this);      // --> asi no funciona
         state.method( (Entity)<EnemyDataBase> this);    // --> asi no funciona
         state.method( ((Entity)<EnemyDataBase>) this);  // --> asi no funciona
   }
}
//-----------------------------------------------------------------

Thank you very much!!

c#

1 Answers

  1. Best Answer

    I understand that your question would be to know if your object is of the same type created, but I am missing some mental information to give you a totally clear answer, so excuse me if I don't get it right. I also don't see where you're creating the object you want to cast but you're trying to pass the same class to it thisinstead of a concrete object.

    If you create a Generic Type and then want to know if that created type is equal to another, you can use two operators in C#, isandas

    the operator isasks if this is of a certain type, which returns an trueor false;

    The operator astries to cast the object and if it can't, it leaves the object in nulland doesn't break your app. Otherwise, it would happen if you want to do the cast like this: (Enemy)MiObjetoCreado;

    //-----------------------------------------------------------------
public class MyEnemy : Enemy
{
   State state;
   Public void Start()
   {
         state = new State();
         
           if(MiObjetoCreado is Entity<EnemyDataBase>)
           {
              state.method(MiObjetoCreado);      
           }
           
           var objetoNuevo = MiObjetoCreado as Entity<EnemyDataBase>;

           if(objetoNuevo != null)
           {
              state.method(MiObjetoCreado);  
           }
   }
}
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