QueryStringBuilder.cs

namespace Utilities
{
    public class QueryStringBuilder : Dictionary<string, string>
    {
        public string Generate()
        {
            if (Count == 0) return string.Empty;
            return "?" + string.Join("&", GenerateSegments());
        }

        private IEnumerable<string> GenerateSegments()
        {
            return Keys.Select(key => key + "=" + this[key]);
        }
    }
}