System.Xml.XmlWriter.WriteAttributeString C# (CSharp) Method

        public void WriteAttributeString(string prefix, string localName, string ns, string value) {
            WriteStartAttribute(prefix, localName, ns);
            WriteString(value);
            WriteEndAttribute();
        }

 public static void writeVertex(XmlWriter writer, Vector2D vert)
 {
     writer.WriteStartElement("vertex");
     writer.WriteAttributeString("x", vert.x.ToString());
     writer.WriteAttributeString("y", vert.y.ToString());
     writer.WriteEndElement();
 }