CODEWITHSUNDEEP
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user2535425
user2535425

Reputation:

Enum behaviour between VB and C#

I've searched and tried many things but I'm not really fully happy.

While converting an old project from VB.Net to C# I found that the behaviour between the 2 languages is very different and breaks the logic in C# if not dealt with.

Consider an enum like:

public enum TestEnum
{
    Val1 = 1,
    Val2 = 2
}

I have this code in VB.Net

// Will contain 1
txthMyHiddenField.Value = TestEnum1.Val1

And also

// Will contain ~/Something?var=1
Dim Url As String = "~/Something?var=" & TestEnum1.Val1

In C# this would have the first case having Val1 and on the second case "~/Something?var=Val1"

The solution so far I could come up with without redesigning lots of code is to go everywhere and do something like:

= myEnum.ToString("d");

// Or

= ((int)myEnum).ToString();

// Or an extension.

I also considered creating an enum "class" but then I would have to change all switch statements, which is an even worse solution.

Am I missing something? Is there a cleaner way?

Upvotes: 1

Views: 253

Answers (2)

JFish222
JFish222

Reputation: 1026

@Rivers,

I added a comment requesting more info in @Tim Schmelter's post but will try to provide a solution in the mean time.

@Eric, is correct in that it appears to come down to the explicit nature of C#. I also agree with @THG that if there is any change of repeatedly requiring this conversion, then an extension method is the cleanest way to go.

I haven't found a way to explicitly filter for enum, so I would be very interested in how such an extension method could be implemented.

In my case, I have limited type filtering and perform runtime validation. (I would obviously prefer compile time):

public static string ToIntString<T>(this T enumVal) where T : struct, IConvertible, IComparable, IFormattable
{
   TestGenericEnum<T>();
   return (Convert.ToInt32(enumVal).ToString();
}

private static void TestGenericEnum<T>()
{
    if (!typeof(T).IsEnum)
        throw new ArgumentException("T must be of type System.Enum");
}

Update: Tossed in IComparable, IFormattable restrictions per @Preston's advice.
Update 2: Bone headed move, can't cast int directly, need to use Convert class.

Upvotes: 1

Tim Schmelter
Tim Schmelter

Reputation: 460340

Why not simply

var url = "~/Somethimg?var=" + (int)myEnum;

For what it's worth, maybe this extension helps:

public static class EnumExtensions
{ 
    public static int AsInt<TEnum>(this TEnum enumType) where TEnum : struct, IConvertible
    {
        if (!typeof(TEnum).IsEnum)
            throw new ArgumentException("TEnum must be an enum type");
        return ((IConvertible)enumType).ToInt32(null);
    }
}

var url = "~/Somethimg?var=" + myEnum.AsInt();

Upvotes: 5

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