Question

I have a function with generic return type. If value parameter is a valid enum value, the method returns the related enum value.

How can I return the related enum value? Compiler error: Cannot convert type ‘int?’ to ‘T’

public static T? GetEnumValue<T>(int? value)
{
    if (value == null)
    {
        return null;
    }

    try
    {
        var enumValues = Enum.GetValues(typeof(T));

        foreach (object enumValue in enumValues)
        {
            if (Convert.ToInt32(enumValue).Equals(value))
            {
                // ERROR: Cannot convert type 'int?' to 'T'
                return (T)value;
            }
        }
    }
    catch (ArgumentNullException)
    {
    }
    catch (ArgumentException)
    {
    }
    catch
    {
    }

    return null;
}

Thanks,

Answer 1

Three changes made it work for me. Changed return type to Nullabel and added where T : struct (nipped from https://stackoverflow.com/a/209219/455904) and changed the return in the middle to return enumValue.

    public static Nullable<T> GetEnumValue<T>(int? value) 
        where T : struct
    {
        if (value == null)
        {
            return null;
        }

        try
        {
            var enumValues = Enum.GetValues(typeof(T));

            foreach (object enumValue in enumValues)
            {
                if (Convert.ToInt32(enumValue).Equals(value))
                {
                    return (T)enumValue;
                }
            }
        }
        catch (ArgumentNullException)
        {
        }
        catch (ArgumentException)
        {
        }
        catch
        {
        }

        return null;
    }