Passing Enum Value from Unity Configuration - dependency-injection

Question

I am having trouble passing enum value from Unity. This is my enum
public enum MyChoice
{
Choice1 = 1,
Choice2 = 2
}
I have registered typeAlias for this Enum Type like below.
<typeAlias alias ="MyChoice" type ="SomeNamespace.MyChoice, SomeAssembly" />
So far so good. Now, I need to pass an enum value to the constructor of a class from the configuration file. I am doing it as follows:
<register type="IMyInterface" mapTo="SomeClass" name="MyClass">
<constructor>
<param name ="choice" value="MyChoice.Choice1" />
</constructor>
</register>
I get an error MyChoice.Choice1 is not a valid value for MyChoice
Any idea ?

Answer 1

For it to work out of the box you should use the actual value for the enum and not the name. In this case instead of "MyChoice.Choice1" you should use "1".
If you want to use the name in the configuration (despite the posted example it is almost always more meaningful to use the enum name) then you could use a type converter.
Here's an example configuration:
<typeAlias alias ="EnumConverter" type ="SomeNamespace.EnumConverter`1, SomeAssembly" />
<register type="IMyInterface" mapTo="SomeClass" name="MyClass">
<constructor>
<param name ="choice" value="Choice1" typeConverter="EnumConverter[MyChoice]" />
</constructor>
</register>
And then create the EnumConverter:
public class EnumConverter<T> : System.ComponentModel.TypeConverter where T : struct
{
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
T result;
if (value == null || !Enum.TryParse<T>(value.ToString(), out result))
{
throw new NotSupportedException();
}
return result;
}
}