Binding a GridView to a Dynamic or ExpandoObject object

Question

I\'m using Rob Conery\'s Massive ORM, and I haven\'t been able to bind the resulting ExpandoObject to a GridView.

I did find another Stacko

Answer 1

I adapted Brian's accepted answer to be a little more concise and LINQ-y:

public static DataTable ToDataTable(this IEnumerable<dynamic> items)
{
    var list = items.Cast<IDictionary<string, object>>().ToList();
    if(!list.Any()) return null;

    var table = new DataTable();
    list.First().Keys.Each(x => table.Columns.Add(x));
    list.Each(x => x.Values.Each(y => table.Rows.Add(y)));

    return table;
}

(This assumes you've defined an IEnumerable.Each extension, which every codebase I've worked on has had).

Answer 2

If we are talking GridView (meaning not WPF) then impromptu can proxy an expando to a poco given an interface. Say we have a list of expando's you can convert them to poco's:

IEnumerable<IMyInterface> listOfPocos
       = Impropmtu.AllActLike<IMyInterface>(listOfExpandos, typeof(INotifyPropertyChanged));

Answer 3

Since you can't bind to an ExpandoObject, you can convert the data into a DataTable. This extension method will do that for you. I might submit this for inclusion to Massive.

/// <summary>
/// Extension method to convert dynamic data to a DataTable. Useful for databinding.
/// </summary>
/// <param name="items"></param>
/// <returns>A DataTable with the copied dynamic data.</returns>
public static DataTable ToDataTable(this IEnumerable<dynamic> items) {
    var data = items.ToArray();
    if (data.Count() == 0) return null;

    var dt = new DataTable();
    foreach(var key in ((IDictionary<string, object>)data[0]).Keys) {
        dt.Columns.Add(key);
    }
    foreach (var d in data) {
        dt.Rows.Add(((IDictionary<string, object>)d).Values.ToArray());
    }
    return dt;
}

Answer 4

Ok, apparently as of now, you just can't bind a GridView control to an ExpandoObject instance. I had to use reflection to convert the ExpandoObject to a POCO class.

Answer 5

adapting from Ben's answer

 public static DataTable ToDataTable(this IEnumerable<dynamic> items)
    {
        if (!items.Any()) return null;

        var table = new DataTable();
        bool isFirst = true;

        items.Cast<IDictionary<string, object>>().ToList().ForEach(x =>
        {
            if (isFirst) 
              {
                x.Keys.Select(y => table.Columns.Add(y)).ToList();
                isFirst = false;
              }
            table.Rows.Add(x.Values.ToArray());
        });

        return table;
    }

Answer 6

I came to this thread after researching on the same topic, I found no solution but constructed my own as I desperately needed this one. So here is my solution without going POCO that really works.

// Fill "list" with your dynamic objects.

// cast a dynamic object to dictionary so we get the properties from it.
var props = list[0] as IDictionary<string, object>;

// create a datatable 
var table = new System.Data.DataTable();
    foreach (var c in props.Keys)
        table.Columns.Add(new DataColumn(c));

foreach (var o in list)
{
    var row = table.NewRow();
    var op =  o as IDictionary<string, object>;
    foreach (var p in op.Keys)
    {
        row[p] = op[p];
    }
    table.Rows.Add(row);
}

And simply bind this table to your grid!

I tested it and it worked for me.