public class Master
{
    public string MasterName = "Something";

    public List<Detail> details = new List<Detail>();
}

public class Detail
{
    public string Foo = "Test";
}

DataGridViewTextBoxColumn column = new DataGridViewTextBoxColumn();
column.DataPropertyName = "Details.Foo";
column.HeaderText = "Foo header";

dgv.Columns.Add(column);

public class FormulariosENT {

    #region PROPERTIES

    public int IdFromulario { get; set; }
    public string DescripcionFormulario { get; set; }

    #endregion

    #region PUBLIC METHODS
    public override string ToString() {

        return DescripcionFormulario;
    }

List<Detail> list = new List<Detail>();
for (int i = 0; i < 10; i++)
{
     Detail d = new Detail();
     d.Foo = "test";
     list.Add(d);
}

this.dgv.DataSource = list;
this.dgv.Columns[0].Visible = false;
DataGridViewTextBoxColumn dgvc = new DataGridViewTextBoxColumn();
dgvc.HeaderText = "列标题";
dgvc.DataPropertyName = "foo";
this.dgv.Columns.Add(dgvc);

public class Detail
{
     private string foo;

     public string Foo
     {
         get { return foo; }
         set { foo = value; }
     }
 }

class MyClass
{
   public int Id;
   public MyOtherClass OtherClass;
}

class MyOtherClass
{
   public string Name;
   public int Number;
}

private void dgv_CellFormatting( object sender, DataGridViewCellFormattingEventArgs e )
{
   MyClass data = dgv.Rows[ e.RowIndex ].DataBoundItem as MyClass;

   dgv.Rows[ e.RowIndex ].Cells[ "colName" ].Value = data.OtherClass.Name;
   dgv.Rows[ e.RowIndex ].Cells[ "colNumber" ].Value = data.OtherClass.Number;
}