CLSA 3.6.2 - Type Coercion from Int16 to Nullable<Enum> is not supported?

rfcdejong posted on Thursday, April 02, 2009

I have an enumeration defined like:

public enum MyColor
{
      red = 1,
      white = 2,
      blue = 3
}

From my datareader i have an value as valuetype System.Int16
In my businessobject i have a property Nullable<MyColor>

Using LoadProperty(), Doing TypeCoerce, it can't convert to the desired type.

Why?

Is this not supported or a missing Coercion?
I traced the code and at cnv.CanConvertFrom(valueType) it steps into the else statement.

cnv = "System.ComponentModel.EnumConverter"
desiredType = "MyNameSpace.MyColor"
valueType = "System.Int16"
value = "1"

catch
{
      TypeConverter cnv = TypeDescriptor.GetConverter(desiredType);
      if (cnv != null && cnv.CanConvertFrom(valueType))
            return cnv.ConvertFrom(value);
      else
            throw;
}

I really don't know and i must use the type coercion since it's my generic mapper calling LoadProperty without knowing which type a property is.
I've no other option then converting it myself first before calling LoadProperty.

Why can't the EnumConverter convert from Int16 ?

rfcdejong replied on Thursday, April 02, 2009

Ok i know why:
http://msdn.microsoft.com/en-us/library/at9d6zbw.aspx

RockfordLhotka replied on Thursday, April 02, 2009