Enum localization

Question

How do you localize enums for a ListBoxFor where multiple options are possible?

For example an enum that contains roles:

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Answer 1

There is a way of using attributes to specify a string to use for enums when displaying them, but we found it way too fiddly when you had to handle localization.

So what we usually do for enums that need to be localized is to write an extension class that provides a method to obtain the translated name. You can just use a switch that returns strings from the usual resources. That way, you provide translated strings for enums via the resources just like you do for other strings.

For example:

public enum Role
{
    Administrator,
    Moderator,
    Webmaster,
    Guest
}

public static class RoleExt
{
    public static string AsDisplayString(this Role role)
    {
        switch (role)
        {
            case Role.Administrator: return Resources.RoleAdministrator;
            case Role.Moderator:     return Resources.RoleModerator;
            case Role.Webmaster:     return Resources.RoleWebmaster;
            case Role.Guest:         return Resources.RoleGuest;

            default: throw new ArgumentOutOfRangeException("role");
        }
    }
}

Which you can use like this:

var role = Role.Administrator;
Console.WriteLine(role.AsDisplayString());

If you keep the RoleExt class implementation next to the enum Role implementation it will effectively become part of the interface for Role. Of course you could also add to this class any other useful extensions for the enum .

[EDIT]

If you want to handle multiple flags settings ("Administrator AND Moderator AND Webmaster") then you need to do things a little differently:

[Flags]
public enum Roles
{
    None          = 0,
    Administrator = 1,
    Moderator     = 2,
    Webmaster     = 4,
    Guest         = 8
}

public static class RolesExt
{
    public static string AsDisplayString(this Roles roles)
    {
        if (roles == 0)
            return Resources.RoleNone;

        var result = new StringBuilder();

        if ((roles & Roles.Administrator) != 0)
            result.Append(Resources.RoleAdministrator + " ");

        if ((roles & Roles.Moderator) != 0)
            result.Append(Resources.RoleModerator + " ");

        if ((roles & Roles.Webmaster) != 0)
            result.Append(Resources.RoleWebmaster + " ");

        if ((roles & Roles.Guest) != 0)
            result.Append(Resources.RoleGuest + " ");

        return result.ToString().TrimEnd();
    }
}

Which you might use like this:

Roles roles = Roles.Administrator | Roles.Guest | Roles.Moderator;
Console.WriteLine(roles.AsDisplayString());

Resource Files

Resource files are the way that you internationalize your strings. For more information on how to use them, see here:

http://msdn.microsoft.com/en-us/library/vstudio/aa992030%28v=vs.100%29.aspx http://msdn.microsoft.com/en-us/library/vstudio/756hydy4%28v=vs.100%29.aspx