Generic method for Similar Objects

C# 4.0 If i have N classes(Entities) with completely the same properties, they don’t have any common interface or any common inheritance I want to have method to be able to pass any of their instances, without copy any properties from one object to another. I think there should be a couple of ways of doing this in .NET 4.0.

e.g somehow using var or dynamik keywords or using generic types. May be something like that:

  开发者_运维问答  public void MyMethod<MyType>(AnyType myInstance)
    {
        Type myType = typeof(T);
        myInstance = myInstance as myType;

        AppendToFile(myInstance.Field1);
        AppendToFile(myInstance.Field2);
    }

Now i am investigating that, may be someone have any ideas about that.

If you don't want to or can't derive them or add an interface, then you will have to use dynamic

I believe this will do it, assuming AppendToFile takes dynamic parameters or the Field1 and Field2 are always the same types.

public void MyMethod(dynamic myInstance)
{
    AppendToFile(myInstance.Field1);
    AppendToFile(myInstance.Field2);
}

The best way would be to change the classes to just implement the interface.

Another approach would be to create the interface that you desire, and then create a default implementation of the interface that just wraps a dynamic object and implements the interface. Then any methods in this default implementation just become pass-throughs to the underlying dynamic.

This would allow you to consistently work with the IMyInterface interface instead of working with the dynamics directly.

For example:

public interface IMyInterface
{
      string Field1 { get; }
      string Field2 { get; }
}

public class MyDefaultInterface : IMyInterface
{
      private Dynamic _dynamic;
      public MyDefaultInterface(dynamic target)
      {
          _dynamic = target;
      }
      public string Field1 { get { return _dynamic.Field1; } }
      public string Field2 { get { return _dynamic.Field2; } }    
}

If you're looking to use dynamic, you can use this:

public void MyMethod(dynamic myInstance)
{
    AppendToFile(myInstance.Field1); //note: you will get no intellisense support
    AppendToFile(myInstance.Field2);
}

One way is to use reflection (not .NET 4.0 specific):

object field1Value = myType.GetField("Field1").GetValue(myInstance);

I have to ask, is it not possible to change the classes to implement the same interface?