using System;

using System.Linq;

using System.Xml;

public class Program

{

        static void Main(string[] args)

        {

            var doc = new XmlDocument();

            doc.LoadXml("<a><c>text</c><b/><ggg/><fff/></a>");

            RemoveEmptyChildNodes(doc);

​

            Console.WriteLine(doc.OuterXml);

        }

​

        private static void RemoveEmptyChildNodes(XmlDocument node)

        {

            foreach (var childNode in node.ChildNodes.OfType<XmlNode>())

            {

                RemoveEmptyChildNodes(childNode, node);

            }

        }

​

        private static void RemoveEmptyChildNodes(XmlNode node, XmlNode parent)

        {

            foreach (var childNode in node.ChildNodes.OfType<XmlNode>().Where(x => x.NodeType != XmlNodeType.Text && x.NodeType != XmlNodeType.Attribute).ToList())

            {

                RemoveEmptyChildNodes(childNode, node);

            }

​

            if (node.InnerXml == String.Empty)

            {

                parent.RemoveChild(node);

            }

        }

}