System.Runtime.Serialization.ExtensionDataReader.GetPrefix C# (CSharp) Method

        internal static string GetPrefix(string ns)
        {
            string prefix;
            ns = ns ?? String.Empty;
            if (!s_nsToPrefixTable.TryGetValue(ns, out prefix))
            {
                lock (s_nsToPrefixTable)
                {
                    if (!s_nsToPrefixTable.TryGetValue(ns, out prefix))
                    {
                        prefix = (ns == null || ns.Length == 0) ? String.Empty : "p" + s_nsToPrefixTable.Count;
                        AddPrefix(prefix, ns);
                    }
                }
            }
            return prefix;
        }

        internal void AddQualifiedNameAttribute(ElementData element, string elementPrefix, string elementName, string elementNs, string valueName, string valueNs)
        {
            string prefix = ExtensionDataReader.GetPrefix(valueNs);

            element.AddAttribute(elementPrefix, elementNs, elementName, String.Format(CultureInfo.InvariantCulture, "{0}:{1}", prefix, valueName));

            bool prefixDeclaredOnElement = false;

            if (element.attributes != null)
            {
                for (int i = 0; i < element.attributes.Length; i++)
                {
                    AttributeData attribute = element.attributes[i];
                    if (attribute != null && attribute.prefix == Globals.XmlnsPrefix && attribute.localName == prefix)
                    {
                        prefixDeclaredOnElement = true;
                        break;
                    }
                }
            }
            if (!prefixDeclaredOnElement)
            {
                element.AddAttribute(Globals.XmlnsPrefix, Globals.XmlnsNamespace, prefix, valueNs);
            }
        }