试试这个:

var result = new List<object>();

foreach (var test in model.ToList()) {
   result.Add(new {Id = test.IdSoc,Nom = test.Nom});
}

对于第二个示例，您必须初始化一个新的List<T>，一个想法是创建一个匿名列表，然后清除它。

var list = new[] { o, o1 }.ToList();
list.Clear();

//and you can keep adding.
while (....)
{
    ....
    list.Add(new { Id = x, Name = y });
    ....
}

或作为扩展方法，应该更容易:

public static List<T> GetEmptyListOfThisType<T>(this T item)
{
    return new List<T>();
}

//so you can call:
var list = new { Id = 0, Name = "" }.GetEmptyListOfThisType();

或者更短，

var list = new int[0].Select(x => new { Id = 0, Name = "" }).Tolist();

您可以创建一个动态列表。

List<dynamic> anons=new List<dynamic>();
foreach (Model model in models)
{
   var anon= new
   {
      Id = model.Id,
      Name=model.Name
   };
   anons.Add(anon);
}

"dynamic"由第一个添加的值初始化。

你可以这样做:

var o = new { Id = 1, Name = "Foo" };
var o1 = new { Id = 2, Name = "Bar" };

var array = new[] { o, o1 };
var list = array.ToList();

list.Add(new { Id = 3, Name = "Yeah" });

对我来说，这似乎有点“俗气”，但它是可行的——如果你真的需要一个列表，不能只使用匿名数组。

如果您使用c# 7或更高版本，您可以使用元组类型而不是匿名类型。

var myList = new List<(int IntProp, string StrProp)>();
myList.Add((IntProp: 123, StrProp: "XYZ"));

根据这个答案，我提出了两种可以完成任务的方法:

    /// <summary>
    /// Create a list of the given anonymous class. <paramref name="definition"/> isn't called, it is only used
    /// for the needed type inference. This overload is for when you don't have an instance of the anon class
    /// and don't want to make one to make the list.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="definition"></param>
    /// <returns></returns>
#pragma warning disable RECS0154 // Parameter is never used
    public static List<T> CreateListOfAnonType<T>(Func<T> definition)
#pragma warning restore RECS0154 // Parameter is never used
    {
        return new List<T>();
    }
    /// <summary>
    /// Create a list of the given anonymous class. <paramref name="definition"/> isn't added to the list, it is
    /// only used for the needed type inference. This overload is for when you do have an instance of the anon
    /// class and don't want the compiler to waste time making a temp class to define the type.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="definition"></param>
    /// <returns></returns>
#pragma warning disable RECS0154 // Parameter is never used
    public static List<T> CreateListOfAnonType<T>(T definition)
#pragma warning restore RECS0154 // Parameter is never used
    {
        return new List<T>();
    }

你可以使用这些方法

var emptyList = CreateListOfAnonType(()=>new { Id = default(int), Name = default(string) });
//or
var existingAnonInstance = new { Id = 59, Name = "Joe" };
var otherEmptyList = CreateListOfAnonType(existingAnonInstance);

这个答案也有类似的想法，但直到我创建了这些方法之后我才发现它。