Accessing an enum in a different namespace

Question

I'm using C# in VS2005. I have a class library that contains several enums common to a number of different projects. When accessing one of these enums I have to specify the whole namespace path to the enum even though I have declared a 'using' directive to the namespace that contains the enum.

For example I have the following enum:

namespace Company.General.Project1
{
   public static class Rainbow
   {
    [Flags]
    public enum Colours
    {
      Red,
      Blue,
      Orange
    }
  }
}

Then in another project I have:

using Company.General.Project1;

namespace Company.SpecialProject.Processing
{
  public class MixingPallette
  {
    int myValue = Company.General.Project1.Colours.Red;
  }
}

Even though I have the 'Using' directive referencing the project that contains the class of the enum, I still have to write the enum longhand. Why can't I do the following...

using Company.General.Project1;

namespace Company.SpecialProject.Processing
{
  public class MixingPallette
  {
    int myValue = Colours.Red;
  }
}

Answer 1

Your enum isn't just in a namespace - it's a nested type. In fact, your sample "working" code wouldn't work, it would have to be

int myValue = (int) Company.General.Project1.Rainbow.Colours.Red;

(Not only do you need to include the Rainbow part, but there's also no implicit conversion from an enum to int.)

Make your enum a top-level type:

namespace Company.General.Project1
{
    [Flags]
    public enum Colours
    {
        Red,
        Blue,
        Orange
    }
}

Then you will be able to write:

using Company.General.Project1;

...

Colours x = Colours.Red;
int y = (int) Colours.Red;

(Note that to use [Flags] effectively, you should be assigning values explicitly, e.g. 1, 2, 4, 8...)

---

EDIT: I've been assuming you really do want to be able to use Colours.Red etc. You can keep your current structure, using a nested type, and just write:

Rainbow.Colours x = Rainbow.Colours.Red;
int y = (int) Rainbow.Colours.Red;

Unless you have a particular reason to make the enum nested, however, I wouldn't.

Answer 2

You can move your enums out of the static class - they can exist in their own right. So this would work:

namespace Company.General.Project1
{
  [Flags]
  public enum Colours
  {
    Red,
    Blue,
    Orange
  }
}

using Company.General.Project1;

namespace Company.SpecialProject.Processing
{
  public class MixingPallette
  {
    int myValue = (int)Colours.Red;
  }
}

But if you keep the enum within this static class, then it can only be referenced in that context:

using Company.General.Project1;

namespace Company.SpecialProject.Processing
{
  public class MixingPallette
  {
    int myValue = (int)Rainbow.Colours.Red;
  }
}