AjaxControlToolkit.Gravatar.GetUrl C# (CSharp) Method

        string GetUrl(string email, int? size, string defaultImage, GravatarRating rating)
        {
            var url = new StringBuilder("http://www.gravatar.com/avatar/");
            url.Append(GetHash(Email));

            if(size == null) size = 80;
            url.Append("?s=");
            url.Append(size);

            if(!String.IsNullOrEmpty(defaultImage)) {
                url.Append("&d=");
                url.Append(defaultImage);
            }
            else if(DefaultImageBehavior != GravatarDefaultImageBehavior.Default) {
                var behaviorName = DefaultImageBehavior.ToString().ToLower();
                switch(DefaultImageBehavior) {
                    case GravatarDefaultImageBehavior.MysteryMan:
                        behaviorName = "mm";
                        break;
                }

                url.Append("&d=" + behaviorName);
            }

            if(rating != GravatarRating.Default) {
                url.Append("&r=");
                url.Append(rating.ToString().ToLowerInvariant());
            }

            return url.ToString();
        }