如何在C＃中的单个对象数组中访问不同类型的类

Question

I have an object array that is supposed to hold objects of different classes. I need to write down the attributes of those classes but don't know how to access them.

For example:

object[] NationalTeam;

possibly holding:

class Swimmer
class Runner

etc.

with different attributes. Can't access them with NationalTeam[i] . Can it be done with overloading [] indexer? If yes, how?

Answer 1

You will have to either:

1. Cast them:

    object teamMember = NationalTeam[0]; if (teamMember is Swimmer) { Swimmer swimmerTeamMember = (Swimmer)teamMember; // Work with swimmer } // ... and so on 

2. Add and implement an interface or base class such as ITeamMember or TeamMember .

    interface ITeamMember { /* common properties */ } class Swimmer : ITeamMember { /* ... */ } ITeamMember[] NationalTeam; 

3. Or use a combination of both.

Eric Lippert (one of the designers of C#) has a fantastic walk through to explain a very similar problem. I suggest that you read it. http://ericlippert.com/2015/04/27/wizards-and-warriors-part-one/