i have a class for build xml sitemap in c# , i use it in a mvc controller to generate sitemap :
public class Location
    {
        public enum eChangeFrequency
        {
            always,
            hourly,
            daily,
            weekly,
            monthly,
            yearly,
            never
        }
        [XmlElement("loc")]
        public string Url { get; set; }
        [XmlElement("changefreq")]
        public eChangeFrequency? ChangeFrequency { get; set; }
        public bool ShouldSerializeChangeFrequency() { return ChangeFrequency.HasValue; }
        [XmlElement("lastmod")]
        public DateTime? LastModified { get; set; }
        public bool ShouldSerializeLastModified() { return LastModified.HasValue; }
        [XmlElement("priority")]
        public double? Priority { get; set; }
        public bool ShouldSerializePriority() { return Priority.HasValue; }
        [XmlElement("image")]
        public Image Image { get; set; }
    }
    [XmlType("image")]
    public class Image
    {
        [XmlElement(ElementName = "loc")]
        public string UrlLocation { get; set; }
        [XmlElement(ElementName = "caption")]
        public string Caption { get; set; }
        [XmlElement(ElementName = "title")]
        public string Title { get; set; }
    }
this is output , when i use it :
<url>
  <loc>http://...</loc>
  <priority>0.5</priority>
    <image>
      <loc>http://...</loc>
    </image>
</url>
but i want correct format , like this :
<url>
  <loc>http://...</loc>
  <priority>0.5</priority>
  <image:image>
    <image:loc>http://...</image:loc>
  </image:image>
</url>
i want to add this prefix to image element , thanks for your help