CODEWITHSUNDEEP
c#.net
user1765862
user1765862

Reputation: 14145

can enum type derive from interface

I have three enums inside my class 

public enum CPUBrandEnum { 
   Intel = 1,
   AMD = 2                    
}

and

public enum CPUTypeIntel {
   Celeron,
   Pentium4
}
public enum CPUTypeAMD {
   ASeries,
   ESeries
}

so I have property which hold cpu brand 

public CPUBrandEnum CPUBrand { get; set; }
public SelectedCPUType ???

but since I don't know which cpu type will be choosed by the user in runtime I don't know how to construct propertytype which will hold choosen cpu.

If those are object I would derive them from some interface ICPUType but in this case (enum) I'm stuck.

Update: Let me explain usage of this property SelectedType.

User will select cpu brand type from CPUBrandEnum, based on that value I will display either CPUTypeIntel of CPUTypeAMD.

So based on that value SelectedCPUType can be one choosed value from CPUTypeXXX enum.

Upvotes: 0

Views: 162

Answers (5)

Matthew Layton
Matthew Layton

Reputation: 42260

No, you can't implement an interface on an enum.

You could do this:

enum CPU
{
    IntelCeleron,
    IntelPentium,
    AmdASeries,
    AmdESeries
}

This approach allows you to pick a CPU based on the values that exist in this enum only, or you could use [System.Flags]

[System.Flags]
enum CPU
{
    Intel = 1,
    Amd = 2,
    Celeron = 4,
    Pentium = 8,
    ASeries = 16,
    ESeries = 32
}

This will allow you to combine values like so

var cpu = CPU.Intel | CPU.Pentium;

But it also opens the playing field to incorrect values like so

var cpu = CPU.Amd | CPU.Pentium;

Upvotes: 2

Deepak Bhatia
Deepak Bhatia

Reputation: 6276

Rather creating two enums, just create a single enum, CPUTye

public enum CPUTypeIntel 
{
   Celeron,
   Pentium4,
   ASeries,
   ESeries
}

enum in .NET can not implement interface, and moreover the enum are just a distinct type that consists of a set of named constants.

EDIT I do not understand why you are trying to have two enum when the nature and the definition is almost same. Both represent the CPUType and to have a single named list for all the CPUType is more logical then the other way how you approach to the problem.

Upvotes: 1

stevethethread
stevethethread

Reputation: 2524

I would have two properties of type CPUTypeIntel, and CPUTypeAMD, and the for each enum have a default value of None, e.g. public enum CPUInteltype {None, Celeron, Pentium4} Then you can later test those properties, and only do work if the value is not None.

Upvotes: 1

Sean
Sean

Reputation: 62472

An enum cannot implement an interface.

If you're looking to mark the absence of an enum value then you've got two option. One is to have an enum member called Unknown (or something similar). For example:

public enum CPUBrandEnum { 
   Unknown = 0,
   Intel = 1,
   AMD = 2                    
}

The other is to use a nullable value:

public CPUBrandEnum? CPUBrand { get; set; }

Upvotes: 1

Jon Skeet
Jon Skeet

Reputation: 1500495

No, enums can't implement interfaces in .NET. They're really just named numbers.

Even if they could implement interfaces, you'd end up with the potential for bad data (e.g. an "Intel ASeries".

It's not clear what you want to do with these values anyway, but it's possible that you should just have one enum with all the valid possibilities. That might not work for your real situation, of course.

Upvotes: 10

Related Questions