title: Generic interface problem
body: <p>I'd like to have one interface for all my grid related tasks.The tasks implement this interface:</p>
  
  <pre><code>public interface IDataForGrid&lt;T&gt;
  {
      IGridResponse&lt;T&gt; GetList(IGridRequest request);
  }
  </code></pre>
  
  <p>The T type is always a DTO class. I cant't create a common interface for this DTOs because they have nothing common.Just a dumb DTO with particular properties.</p>
  
  <p>I'd like to use it like this :</p>
  
  <pre><code>public class Service1
  {
      public IGridResponse CreateResponse(IGridRequest request)
      {
  
          ...
          IDataForGrid&lt;T&gt; aa;
  
          if(request == 1) aa = new CustomerGridData;
          if(request == 2) aa = new OrderGridData;
  
          var coll = aa.GetList();
      }
  }
  
  public class CustomerGridData : IDataForGrid&lt;CustomerDTO&gt;
  {
     ...
  }
  </code></pre>
  
  <p>The problem is I don't know what to put instead of the T. </p>