XDocument 使用

摘要：

正文：

1.引入XDocument的命名空间

using System.Xml.Linq;

2. List<CourseItem> to XML doc

        //List<CourseItem> to XML
        public XDocument InitDownloadData(List<CourseItem> item)
        {
            XElement courseItemElement = new XElement("Courses",
                item.Select(c => new XElement("Course",
                    new XAttribute("Title", c.Title),
                    new XElement("Description", c.Description),
                    new XElement("Owner", c.Owner),
                    new XElement("PublishDate", c.PublishDate),
                    new XElement("Rating", c.Rating),
                    new XElement("TotalPoints", c.TotalPoints),
                    new XElement("Modules",
                        c.Modules.Select(m => new XElement("Module",
                            new XAttribute("Title", m.Title),
                            new XElement("Description", m.Description),
                            new XElement("Points", m.Points),
                            new XElement("Materials",
                                m.Materials.Select(ma => new XElement("Material",
                                    new XAttribute("Title", ma.Title),
                                    new XElement("Id", ma.Id),
                                    new XElement("MType", ma.MType))))))),
                    new XElement("ID", c.ID))));
            XDocument doc = new XDocument(courseItemElement);

            if (doc != null)
                return doc;
            else return null;

        }

3. XML to List<CourseItem>

        //XML to List<CourseItem> Note: doc 是由List<CourseItem> 转化而来
        public List<CourseItem> DeserializeToClass(XDocument doc)
        {
            if (doc != null)
            {
                var courses =
                    (from c in doc.Descendants("Course")
                     select new CourseItem
                     {
                         Title=c.Attribute("Title").Value ,
                         ID = c.Element("ID").Value,
                         Description =c.Element ("Description").Value ,
                         Owner = c.Element("Owner").Value,
                         TotalPoints =c.Element ("TotalPoints").Value ,
                         PublishDate =DateTime.Parse(c.Element ("PublishDate").Value),
                         Rating=c.Element ("Rating").Value ,
                         Modules = (from m in c.Descendants("Module")
                                   select new Module
                                   {
                                       Title = m.Attribute("Title").Value,
                                       Description=m.Element ("Description").Value,
                                       Points =m.Element ("Points").Value ,
                                       Materials = (from ma in m.Descendants("Material")
                                                   select new Material {
                                                       Title = ma.Attribute("Title").Value,
                                                       Id = ma.Element("Id").Value,

                                                       //string to enum conversion in C#
                                                       MType=(MaterialType)Enum.Parse (typeof(MaterialType),ma.Element ("MType").Value )
                                                   }).ToList()
                                   }).ToList()
                     }).ToList();

                if (courses != null)
                    return courses;
            }
            return null;
        }

4. CourseItem, Module, Material类型定义

    class CourseItem
    {
        private string _title;
        public string Title { get { return _title; } set { _title = value; } }

        private string _id;
        public string ID { get { return _id; } set { _id = value; } }

        private string _description;
        public string Description { get { return _description; } set { _description = value; } }

        private string _totalPoints;
        public string TotalPoints { get { return _totalPoints; } set { _totalPoints = value; } }

        private string _level;
        public string Level { get { return _level; } set { _level = value; } }

        private string _owner;
        public string Owner { get { return _owner; } set { _owner = value; } }

        private string _rating;
        public string Rating { get { return _rating; } set { _rating = value; } }

        private Category _category;
        public Category Category { get { return _category; } set { _category = value; } }

        private DateTime _pubDate;
        public DateTime PublishDate { get { return _pubDate; } set { _pubDate = value; } }

        public List<Module> Modules { get; set; }
    }

    public class Module
    {
        public string Title { get; set; }
        public string Description { get; set; }
        public string Points { get; set; }
        public List<Material> Materials { get; set; }
    }

    public class Material
    {
        public string Title { get; set; }
        public string Id { get; set; }
        public MaterialType MType { get; set; }
    }

参考：

http://*.com/questions/1542073/xdocument-or-xmldocument?rq=1

http://*.com/questions/1187085/string-to-enum-conversion-in-c-sharp