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How can I assign TypeConverter to Enum in `Options`?

Open TetraTheta opened this issue 5 months ago • 0 comments

I've declared Options which will be used for parsing command line.

public class Options {
  // ...
  [Option('o', "operation", HelpText = "")]
  [TypeConverter(typeof(OperationConverter))]
  public Operation Operation { get; set; }
}

And the Operation looks like this:

[TypeConverter(typeof(OperationConverter))]
public enum Operation {
  // ...
  CreateDirectory,
  // ...
}

Since CreateDirectory is quite long to type in command line, I want to allow cd as valid Operation.CreateDirectory

public class OperationConverter : EnumConverter {
  // ... candidates for other enum values
  private static readonly List<string> OperationCandidate = ["createdirectory", "cd"];

  // ...
  public override object ConvertFrom(ITypeDescriptorContext? ctx, CultureInfo? ci, object value) {
    if (value is string s) {
      string l = s.Trim().ToLowerInvariant();
      // ...
      if (OperationCandidate.Contains(l)) return Operation.CreateDirectory;
      // ...
    }
  }
}

But I can't assign this OperationConverter to Options.Operation. I don't see anything that might be related to this.

#83 says it is resolved, but at the bottom of that issue, someone said:

I dont think this works in the latest version. I tried annotating my option's property, but the converter is not invoked. Instead I had to register it using TypeDescriptor.AddAttributes().

But I don't see any methods named .AddAttributes() in TypeDescriptor. this has .AddAttributes(), but this doesn't seem to work.

  private static void Main(string[] args) {
    // ...
    TypeDescriptor.AddAttributes(typeof(Operation), new TypeConverterAttribute(typeof(OperationConverter)));
    // other logic + command line parsing
  }

Now I'm completely lost. Wiki doesn't provide any useful information that I can easily access.

How can I assign TypeConverter to Enum in Options?

TetraTheta avatar Jun 06 '25 08:06 TetraTheta