c# - 如何使用 linq 读取 xml 文件

Question

我有这个 db.xml 文件

<items>
 <item>
  <title>Title1</title>
  <year>2013</title>
  <categories>
   <category>Category1</category>
   <category>Category2</category>
   <category>Category3</category>
  </categories>
  <count>10</count>
 </item>
 (and so on)
</items>

我是这样读的：

var items = from item in xdoc.Descendants("item")
               select new
               {
                   Title = item.Element("title").Value,
                   Year = item.Element("year").Value,
                   Categories = item.Element("categories").Value, // I know this is wrong 
                   Count = item.Element("count").Value
           };

问题是我如何阅读类别并将它们添加到列表中？

foreach (var item in items)
{
    book.Title = item.Title;
    book.Year = item.Year;
    foreach (var Category in Categories)
    {
        book.Categories.Add(Category);
    }
    book.Count = item.Count;
    books.Add(book);
}

Answer 1

最好使用强制转换 (to string， toint等，然后直接读取元素的值。这里是返回整数值的查询Year和Count属性。Categories是IEnumerable<string>：

var items = from item in xdoc.Descendants("item")
            select new {
               Title = (string)item.Element("title"),
               Year = (int)item.Element("year"),
               Count = (int)item.Element("count"),
               Categories = from c in item.Element("categories").Elements()
                            select (string)c                   
            };

如果你想Categories这样List<string>解析类别：

 Categories = item.Element("categories")
                  .Elements()
                  .Select(c => (string)c)
                  .ToList()

Answer 2

您可以获取其元素列表

已编辑

var items = from item in xdoc.Descendants("item")
       select new
       {
           Title = item.Element("title").Value,
           Year = item.Element("year").Value,
           Categories = item.Descendants("categories").Descendants().Select(x=>x.Value).ToList(),
           Count = item.Element("count").Value
       };