Home / Questions / 442572
Accepted
Iván Rodríguez
Asked: 2022-04-09 03:29:08 +0800 CST 2022-04-09 03:29:08 +0800 CST

How to access the data of a structure declared inside an interface? C#

  • 772

I have an interface and I have declared a structure inside it. I want the interface to handle events. At first I had it like this:

public interface IEventInfo
{
    public int Health { set; get; }    
    public int Lives { set; get; }      
    public int Damage { set; get; }     
    public int Coin { set; get; }     
    public int Tokens { set; get; }     
    public int Score { set; get; }      
    public string Power { set; get; }  
    public string Weapon { set; get; }  
    public string Armor { set; get; }   

}

But after using it in a couple of classes I have thought that it would be much more comfortable, tidy and clean if I did it this way.

public interface IEventInfo
{
    public struct SData
    {
        public int Health;     
        public int Lives;      
        public int Damage;    
        public int Coin;       
        public int Tokens;     
        public int Score;      
        public string Power;  
        public string Weapon;  
        public string Armor;   
    }
    public SData Data { set; get; }
}

And so I would only have to implement the following in all my classes.

public SData Data { set; get; }

The issue is that it is giving me an error when trying to access the value of the variables:

public class myClass : MonoBehaviour, IEventInfo
{
      public SData Data { set; get; }

      public myClass()
      {
        Data = new IEventInfo.SData();

        Data.Health = 100; 
        Data.Lives = 1;
        Data.Damage = 10;
        Data.Coin = 5;
        Data.Tokens = 1;
        Data.Score = 50;
      }
}

Compiler error CS1612 Cannot modify return value of 'expression' because it is not a variable

I go to the error page

And it tells me the following:

To modify the structure, first assign it to a local variable, modify the variable, and then assign the variable back to the collection element.

I do this but the error persists:

Data = new IEventInfo.SData();

int tmp = Data.Health;
tmp = 100;
Data.Health = tmp;

Does anyone know how to do it correctly? Thank you so much!!

c#

1 Answers

  1. Best Answer

    I don't know if it's exactly what you want, but I'll give you an answer.

    Types cannot be defined in interfaces, that is prohibited. What you can do is the following:

    Define your structure in a separate class, not in the interface:

    public struct SData
{
    public int Health;
    public int Lives;
    public int Damage;
    public int Coin;
    public int Tokens;
    public int Score;
    public string Power;
    public string Weapon;
    public string Armor;
}

    Your interface would then look like this:

    public interface IEventInfo
{
    SData Data { set; get; }
}

    The way to use it would be something like this:

    public class myClass :IEventInfo
{
    public SData Data { get; set;}

    public void prueba()
    {
        var datos = new SData();
        datos.Armor = "1";
        //....
        Data = datos;
    }
}
    • 1