Create c# dynamic object from elements of a list

Question

how to convert : A List :

var list = new List<string>(){"str1","str2"}

to a anonymous object :

var anonymousObject = new {str1 = "str1",str2 = "str2"}

during runtime

i'm trying to join two data tables using lambda expressions. when i have to join on a single column its easy and it looks like this <code> Table1.Join(Table2, leftTable => leftTable["joincolumn"], rightTable => rightTable["joincolumn"], (leftTable,rightTable) => new {leftTable,rightTable} ) </code> But i have an list in place of "joinColumn" and this needs to be handled using a dynamic object <code> new {column1=leftTable.column1,column2=leftTable.column2} </code> and my list has column1 and column2 — Nikhil
– Nikhil, Commented May 18, 2016 at 0:08
Do you want to slice List items into object of two properties? — Hari Prasad
– Hari Prasad, Commented May 18, 2016 at 0:13

vendettamit · Accepted Answer · 2016-05-18 00:20:37Z

3

You can use the ExpandoObject which will give you the feature of dynamic type.

        var list = new List<string>() { "str1", "str2" };
        ExpandoObject obj = new ExpandoObject();
        var store = (IDictionary<string, object>)obj;

        list.ForEach(x => store.Add(x, x));

        dynamic lst  = obj;
        var val = lst.str1; // Test

answered May 18, 2016 at 0:20

vendettamit

14.7k2 gold badges36 silver badges56 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

farid bekran · Accepted Answer · 2016-05-18 05:15:52Z

You can also use extension method represented below (from here).

Because converting list to dynamic object by iterating on items manually can be painful when there is many situations like this in your application.

You can use this extension method like this:

  dynamic list = new List<string>() { "str1", "str2" }
       .ToDictionary(dd => dd, dd => (object)dd)
       .ToExpando();

The extension method:

    public static ExpandoObject ToExpando(this IDictionary<string, object> dictionary)
    {
        var expando = new ExpandoObject();
        var expandoDic = (IDictionary<string, object>)expando;

        // go through the items in the dictionary and copy over the key value pairs)
        foreach (var kvp in dictionary)
        {
            // if the value can also be turned into an ExpandoObject, then do it!
            if (kvp.Value is IDictionary<string, object>)
            {
                var expandoValue = ((IDictionary<string, object>)kvp.Value).ToExpando();
                expandoDic.Add(kvp.Key, expandoValue);
            }
            else if (kvp.Value is ICollection)
            {
                // iterate through the collection and convert any strin-object dictionaries
                // along the way into expando objects
                var itemList = new List<object>();
                foreach (var item in (ICollection)kvp.Value)
                {
                    if (item is IDictionary<string, object>)
                    {
                        var expandoItem = ((IDictionary<string, object>)item).ToExpando();
                        itemList.Add(expandoItem);
                    }
                    else
                    {
                        itemList.Add(item);
                    }
                }

                expandoDic.Add(kvp.Key, itemList);
            }
            else
            {
                expandoDic.Add(kvp);
            }
        }

        return expando;
    }

Collectives™ on Stack Overflow

Create c# dynamic object from elements of a list

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related