如何识别具有枚举返回类型的公共类属性？

Question

I have automatically generated service references and I need to analyze them to identify classes with public properties that return enums . This is for an asp.net project that was originally serializing enums as int and was converted to string , so I'm trying to produce a list of enums and their int/string values.

I just copied & pasted all of the service references into a .NET console project and I'm able to enumerate the properties and I am focusing on a known enum for testing, but the output from the below code is not identifying it as an enum when it is:

[AxdEntity_PurchTable_1\Property\PurchStatus]: Nullable`1; False

How can I correctly identify it as an enum ?

My Reflection Code:

var q = from t in Assembly.GetExecutingAssembly().GetTypes()
            where t.IsClass && t.Namespace == "MyNamespace"
            && t.Name == "AxdEntity_PurchTable_1" // I plan to remove this, but focusing on one class
            select t;

foreach (var refClass in q.ToList())
{
    foreach (var prop in refClass.GetProperties())
    {
        if (prop.Name == "PurchStatus")
        {
            // How do I determine if the return type is an enum?
            Console.WriteLine($"[{refClass.Name}\\Property\\{prop.Name}]: {prop.PropertyType.Name}; {prop.PropertyType.BaseType.IsEnum}");

            // OUTPUT: [AxdEntity_PurchTable_1\Property\PurchStatus]: Nullable`1; False

            // prop.PropertyType.BaseType.IsEnum == false?
        }
    }
}

Automatically generated service reference sample code:

namespace MyNamespace
{
    // <... Many other generated classes in this namespace>
    public partial class AxdEntity_PurchTable_1
    {
        private System.Nullable<AxdEnum_PurchStatus> purchStatusField;
        
        // <... Many other properties in this class ...>
        public System.Nullable<AxdEnum_PurchStatus> PurchStatus
        {
            get
            {
                return this.purchStatusField;
            }
            set
            {
                this.purchStatusField = value;
            }
        }
    }
    
    // <... Many other enums in this namespace ...>
    public enum AxdEnum_PurchStatus
    {
        None,
        Backorder,
        Received,
        Invoiced,
        Canceled,
    }
}

Answer 1

You have to check if the generic type is Nullable<> and if its parameter is an enum. This should detect normal and nullable enum properties:

foreach (var refClass in q.ToList())
{
    foreach (var prop in refClass.GetProperties())
    {
        if(
            prop.PropertyType.IsEnum
            || (prop.PropertyType.IsGenericType
            && prop.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>)
            && prop.PropertyType.GetGenericArguments()[0].IsEnum))
        {
            Console.Write(prop);
        }
    }
}

Answer 2

PurchStatus property type is not just enum, but nullable enum. Use Nullable.GetUnderlyingType (returns null if type is not nullable so coalesce with type itself):

foreach (var refClass in q.ToList())
{
    foreach (var prop in refClass.GetProperties())
    {
        var type = Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType;
        if (type.IsEnum)
        {
            // do something
        }
    }
}