Question

我有一个匿名类型列表List<'a>, a' is new {OptionSetValue servingTime, OptionSetValue servingGroup, string servingClass, string desc, string childName, Guid childId, EntityReference item, OptionSetValue type, Guid sensitivity}

我已经在foreach语句中构造了一个这样的列表，并且需要将该列表从for循环（groupedAllergies）外部添加到另一个相同类型的列表中。显然，我写的内容不起作用，因为对象不包含我要访问的匿名类型的定义。我该如何补救？！

    var groupedAllergies = new List<object>(); <--- problem

    foreach (var line in items)
    {
        OptionSetValue servingTime = line.servingTime;
        OptionSetValue servingGroup = line.servingGroup;
        string servingClass = line.servingClass;
        string desc = line.desc;
        string childName = line.childName;
        Guid childId = line.childId;
        Guid sensitivity = line.sensitivity;


         var queryAllergyItems = groupAllergies.Where(e => e.servingClass == servingClass
                                                          && e.servingTime == servingTime
                                                          && e.servingGroup == servingGroup
                                                          && e.desc == desc
                                                          && e.allergies.Intersect(allergies).Any()).Select(r => new
                                                          {
                                                              r.item,
                                                              r.type,
                                                              r.allergies
                                                          }).ToList();

         var items = queryAllergyItems.Select(r => new
         {
             servingTime,
             servingGroup,
             servingClass,
             desc,
             childName,
             childId,
             r.item,
             r.type,
             sensitivity = r.allergies.Intersect(allergies).First()


          }).ToList();

          items.ForEach(e => groupedAllergies.Add(e));

    }



     foreach(var allergy in groupedAllergies)
     {
          var servingTime = allergy.servingTime;  
          //object doesn't have definition for servingTime!!

     }

这是有效的解决方案吗？！

var o = new { servingTime = new OptionSetValue(), servingGroup = new OptionSetValue(), servingClass = "", desc = "", childName = "", childId = new Guid(), item = new EntityReference(), type = new OptionSetValue(), sensitivity = new Guid() };

var groupedAllergies = new[] { o }.ToList();
groupedAllergies.Clear();

Answer 1

尝试一下：

List<dynamic> list = new List<dynamic>();

这将创建一个可以存储任何类型对象的列表。

Answer 2

如果您使用的是C＃7，则实际上不需要匿名类型。您可以使用值元组。它们基本上是具有特殊语言支持的元组。

https://blogs.msdn.microsoft.com/mazhou/2017/05/26/c-7-series-part-1-value-tuples/

对于List<dynamic>，取决于类型是否相同，动态性会变得非常快。不会比静态类型快。

对象没有为serveTime定义

2 个答案: