//An example of a simple class 
public class MyCustomClass
{
    public MyCustomClass(int intValue, double doubleValue, string stringValue)
    {
        IntValue = intValue;
        DoubleValue = doubleValue;
        StringValue = stringValue;
    }

    public int IntValue { get; set; }
    public double DoubleValue { get; set; }
    public string StringValue { get; set; }
}

//Collection with some MyCustomClass objects 
public class MyCollection : List<MyCustomClass>
{
    public MyCollection()
    {
        //Add some data 
        Add(new MyCustomClass(10, 11.12, "some string 1"));
        Add(new MyCustomClass(20, 21.33, "some string 2"));
    }
}

<Window x:Class="TestApplication.Tutorial.DataTypesWindow" 
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
           xmlns:df="clr-namespace:Dapfor.Wpf.Controls;assembly=Dapfor.Wpf" 
           xmlns:Tutorial="clr-namespace:TestApplication.Tutorial"
           Title="Objects of arbitrary classes" Height="352" Width="671"> 

  <Window.Resources> 
    <Tutorial:MyCollection x:Key="myCollection"/> 
  </Window.Resources> 

  <df:GridControl Name="grid" ItemsSource="{StaticResource myCollection}"> 
    <df:GridControl.Headers> 
      <df:Header ScrollType="Stretch"> 
        <df:Header.Columns> 
          <df:Column Id="IntValue" Title="Int Value" /> 
          <df:Column Id="DoubleValue" Title="Double Value" /> 
          <df:Column Id="StringValue" Title="String Value" /> 
        </df:Header.Columns> 
      </df:Header> 
    </df:GridControl.Headers> 
  </df:GridControl> 
</Window>

// Interaction logic for DataTypesWindow.xaml 
public partial class DataTypesWindow : Window
{
    public DataTypesWindow()
    {
        InitializeComponent();

        //Bind the Wpf GridControl to the collection MyCollection using program means 
        IList<MyCustomClass> collection = new List<MyCustomClass>
        collection.Add(new MyCustomClass(10, 11.12, "some string 1"));
        collection.Add(new MyCustomClass(20, 21.33, "some string 2"));

        grid.ItemsSource = collection;
    }
}

Row row = grid.Rows[1];
row.Add(new object[] { 200, null,"subitem1"});
row.Add(new object[] { 33, 33.33,"subitem2" });