Declaration of Anonymous types List [duplicate]

Answer 1

You can make a list like this, but you'll again have to use some serious hackery, and you'll have to use some "type by example" situations. For example:

// create the first list by using a specific "template" type.
var list = new [] { new { Name="", Phones=new[] { "" } } }.ToList();

// clear the list.  The first element was just an example.
list.Clear();

// start adding "actual" values.
list.Add(new { Name = "Krishna", Phones = new[] { "555-555-5555", "666-666-6666" } });

Answer 2

It involves a bit of hackery but it can be done.

static List<T> CreateListFromSingle<T>(T value) {
  var list = new List<T>();
  list.Add(value);
  return list;
}

var list = CreateListFromSingle(
   new{Name="Krishna", 
                 Phones = new[] {"555-555-5555", "666-666-6666"}}
                );

Answer 3

How about dynamic?

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


dynamicList.Add(new { Name = "Krishna",  Phones = new[] { "555-555-5555", "666-666-6666" } }); 

Answer 4

You can't make a collection of an anonymous type like this.

If you need to do this, you'll need to either use List<object>, or make a custom class or struct for your type.

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Edit:

I'll rephrase this:

Although, technically, it's possible to make a list of an anonymous type, I would strongly recommend never doing this. There is pretty much always a better approach, as doing this is just making code that is nearly unmaintainable. I highly recommend making a custom type to hold your values instead of using anonymous types.

A custom type will have all of the same capabilities (since anonymous types are defined, by the compiler, at compile time), but will be much more understandable by the developer who follows you...

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And just to play, too, here's my entry for "code I'd never actually want to use in the real world":

var customer = new { Name = "Krishna", Phones = new[] { "555-555-5555", "666-666-6666" } };
var someVariable = new[]{1}.Select(i => customer).ToList();

Answer 5

I spent quite a lot of time trying to find a way to save myself some time using a list of anonymous types, then realised it was probably quicker just to use a private class inside the current class...

private class Lookup {
    public int Index;
    public string DocType;
    public string Text;
}
private void MyMethod() {
    List<Lookup> all_lookups = new List<Lookup> {
        new Lookup() {Index=4, DocType="SuperView", Text="SuperView XML File"},
        new Lookup() {Index=2, DocType="Word", Text="Microsoft Word Document"}
    };
    // Use my all_lookups variable here...

}

Answer 6

I don't think this is possible. Maybe in C# 4 using the dynamic keyword?