Question

I have my repositories setup like below.

interface IRepository<T> where T : DataRow
{
  T Get(int key);
}

interface ICartonRepository : IRepository<CartonDataRow>
{

}

class CartonRepository : ICartonRepository
{
  public CartonDataRow Get(int key)
  {

  }
}

I also have a PackRepository which is defined in the same way as the CartonRepository. What I would like to do is something like the following.

IRepository<DataRow> repository;
switch (rowType)
{
  case Carton:
    repository = new CartonRepository();
    break;
  case Pack:
    repository = new PackRepository();
    break;
}

Is there a way I can achieve this?

Answer 1

For C# 3.5 you will have to add the following:

public interface IRepository {
   DataRow Get(int key);
}

public abstract class Repository<T> : IRepository<T>, IRepository
    where T : DataRow
{
   public abstract T Get(int key);

   DataRow IRepository.Get(int key) {
       return this.Get(key);
   }
}

Then change CartonRepository to class CartonRepository : Repository<CartonDataRow> (I do not think you need ICartonRepository, but you can use it if you want). Then

IRepository repository;
switch (rowType)
{
  case Carton:
    repository = new CartonRepository();
    break;
  case Pack:
    repository = new PackRepository();
    break;
}