Hello InfraOracle,

You are missing two important things. First in order for the WebDataGrid to propery add fields, you must make id bound and assign the DataKeyFields to Id, and secondly you will want to use ClientIDMode="Static".  So your web data grid should look like this:

<ig:WebDataGrid ID="WebDataGrid1" ClientIDMode="Static" runat="server" Visible="true" Height="350px" Width="400px" AutoGenerateColumns="false" DataKeyFields="Id" onrowadding="WebDataGrid1_RowAdding">
    <Columns>
        <ig:BoundDataField DataFieldName="Id" Key="Id" Hidden="true">
        </ig:BoundDataField>
        <ig:BoundDataField DataFieldName="Name" Key="Name">
            <Header Text="Name" />
        </ig:BoundDataField>
        <ig:BoundDataField DataFieldName="Type" Key="Type">
            <Header Text="Type" />
        </ig:BoundDataField>
    </Columns>
    <Behaviors>
        <ig:EditingCore AutoCRUD="false">
            <Behaviors>
            </Behaviors>
        </ig:EditingCore>
    </Behaviors>
</ig:WebDataGrid>

Next you will want to change your javascript row add to actually have data; as all fields must be populated for the row add to work.

<script type="text/javascript">
function AddRow() {
    var grid = $find("WebDataGrid1");
    var row = new Array(grid.get_rows().length, "Name", "Employee"); // create a new empty row
        grid.get_rows().add(row);
    }
</script>

Finally you will need to wireup the rowAdding event to handling adding the new row, as well as storing the list in the session to handle keeping the data managed:

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
             List<Employee> Details = new List<Employee>();
      for (int i = 0; i < 2; i++)
            {
         Employee obj = new Employee();
                   obj.Name = "David";
                   obj.Type =  "Employee";
                   obj.Id = i;
                   Details.Add(obj);
            }
        Session.Add("MyList", Details);
      }

     WebDataGrid1.DataSource = Session["MyList"];
     WebDataGrid1.DataBind();
}

protected void WebDataGrid1_RowAdding(object sender, Infragistics.Web.UI.GridControls.RowAddingEventArgs e)

{
        var MyList = (List<Employee>)Session["MyList"];
    MyList.Add(new Employee() { Name = (string)e.Values["Name"], Type = (string)e.Values["Type"] });

}

With the above code, your list will get initialized on pageload, and then on postback it will load the current list from the session. When you add a row, the RowAdding event will trigger first and you will add the new item to the list, then it will get loaded with the session.

Hope that helps you on your way.

Sincerely,
Jon
Infragistics, Inc.
http://es.infragistics.com/help/