CODEWITHSUNDEEP
c#enumsstatic-methods
tb189
tb189

Reputation: 2012

Static construction methods for enums in C#

I'm trying to add static methods to a C# enum. By adding a static class, I can create a 'getter' method, which converts the enum value in e.g. a byte. However, I cannot seem to make a 'construction' method, which takes the byte and converts it into an enum. In java, I would use the below code without the separate static class.

Enum code:

public enum PoseLocation {

  UP,
  DOWN,
  LEFT,
  RIGHT,
  UP_LEFT,
  UP_RIGHT,
  DOWN_LEFT,
  DOWN_RIGHT

}

public static class PoseLocationMethods {

  public static byte toByte (this PoseLocation location) {
    return (byte)location;
  }

  public static PoseLocation fromByte (byte poseByte) {
    return (PoseLocation)poseByte;
  }

}

Method calls:

byte poseByte = PoseLocation.UP.toByte (); //OK
PoseLocation fromByte = PoseLocation.fromByte (poseByte); //this does not work

Upvotes: 1

Views: 984

Answers (1)

Sweeper
Sweeper

Reputation: 270780

You seem to think that fromByte is also an extension method...

Look at the declaration carefully:

public static PoseLocation fromByte (byte poseByte)

Do you see the word this? No. So it's not an extension method. It's just a normal static method like any other. To call a static method, you need to put the class in which it is declared in in front. In this case, fromByte is declared in PoseLocationMethods, so you should do:

PoselocationMethods.fromByte(1);

However, I don't think fromByte belongs to the PoseLocationMethods class. You might want to write an extension method for byte:

public static PoseLocation ToPoseLocation(this byte poseByte) {
    return (Poselocation)poseByte;
}

Alternatively, get rid of these To and From methods. I think using a cast is clear enough.

Upvotes: 1

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