CODEWITHSUNDEEP
c#asp.netdynamic
Biswajeet
Biswajeet

Reputation: 362

how to convert dynamic to list<dynamic>

i have a variable swimlaneAttribute:

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

but in a function i have a return type of dynamic

public dynamic GetSwimlaneAttribute(List<ProjectSwimlaneAttribute> swimlaneAttributeTable, Dictionary<string, string> dic)
    {
        dynamic swimlaneAttributes = null;

        swimlaneAttributes = swimlaneAttributeTable.Select(s => new
        {
            ID = s.Id,
            DataType = s.AttributeDataType,
            IsCriticalField = s.IsCriticalField,
        });
        return swimlaneAttributes;
    }

this will return some records from table parameter that i am passing!!

now i have to call this GetSwimlaneAttribute function, in return i will get all the required records(from a table) but when i pass this to swimlaneAttributes it goes to catch block!!!

swimlaneAttributes = GetSwimlaneAttribute();

if i pass it this way, (i think the record count becomes 0)

//swimalneAttributes = GetSwimlaneAttribute as List<dynamic>;

So how to convert Dynamic to List

Thanks!

Upvotes: 6

Views: 30218

Answers (3)

Mohamed
Mohamed

Reputation: 520

why don't you try this way?

public List<dynamic> GetSwimlaneAttribute(List<ProjectSwimlaneAttribute> swimlaneAttributeTable, Dictionary<string, string> dic)
{
    List<dynamic> swimlaneAttributes = new List<dynamic>(); // modified dynamic to List<dynamic>

    swimlaneAttributes = swimlaneAttributeTable.Select(s => new
    {
        ID = s.Id,
        DataType = s.AttributeDataType,
        IsCriticalField = s.IsCriticalField,
    });
    return swimlaneAttributes;
}

Upvotes: 0

Jon Skeet
Jon Skeet

Reputation: 1502806

You're currently returning a sequence of anonymous type objects. That sequence can't be cast to a List<T> because it isn't a List<T>.

You could change the declaration to:

IEnumerable<dynamic> GetSwimlaneAttribute(...)

with no change to the body of the code - then to get a List<dynamic> just call it as:

List<dynamic> list = GetSwimlaneAttribute(...).ToList();

If you absolutely can't change the declaration, you could convert it outside the method:

IEnumerable<dynamic> sequence = GetSwimlaneAttribute(...);
List<dynamic> list = sequence.ToList();

Or call the extension method directly:

List<dynamic> list = Enumerable.ToList<dynamic>(GetSwimlaneAttirbute(...));

However, you should be aware that anonymous types don't cross assembly boundaries (without a bit of hackery). You should strongly consider creating a named type for this instead.

Additionally, your method body is a bit crufty - you declare a variable and assign it a null value, then immediately assign a different value, and then just return that value. The whole thing could be written as:

return swimlaneAttributeTable.Select(s => new
{
    ID = s.Id,
    DataType = s.AttributeDataType,
    IsCriticalField = s.IsCriticalField,
});

Upvotes: 5

Mohamed
Mohamed

Reputation: 520

How about this one?

  List<dynamic> lstDynamic = new List<dynamic>();
  lstDynamic.Add(GetSwimlaneAttribute());

and use lstDynamic.

Upvotes: 1

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