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c#enumstype-conversionflagsuint64
Joel in Gö
Joel in Gö

Reputation: 7570

How to get a flags enum to convert to UInt64 with a TypeConverter

I have a class which takes a generic class TState in its constructor, under the condition that TState can be converted to a UInt64using a TypeConverter. It will then be used as flags.

I want to use a [Flags] enum for TState, but even if I define it as 

[Flags]  
public enum EState : ulong
{
    None = 0x0,
    State1= 0x1,
    State2= 0x2,
    State3= 0x4
}

then if TypeConverter typeConv = TypeDescriptor.GetConverter(typeof(EState)); typeConv.CanConvertTo(typeof(UInt64))is false.

How can I make an enum which will convert appropriately? Thanks!

Upvotes: 3

Views: 2118

Answers (1)

Aliostad
Aliostad

Reputation: 81660

You can use Convert.ChangeType():

[Flags]
private enum MyEnum1 : ulong 
{
   A =1,
   B = 2
}

And then

MyEnum1 enum1 = MyEnum1.A | MyEnum1.B;
ulong changeType = (ulong) Convert.ChangeType(enum1, typeof (ulong));

UPDATE

Why TypeDescriptor does not work?

According to docs:

This method looks for the appropriate type converter by looking for a TypeConverterAttribute. If it cannot find a TypeConverterAttribute, it traverses the base class hierarchy of the class until it finds a primitive type.

TypeDescriptor and TypeConvertor work with ExpandableObjectConverter while Convert works with IConvertible.

Upvotes: 2

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