将GridControl绑定到SortedList

我正在尝试将一个表（特别是DevExpress GridControl）绑定到SortedList。我希望表的第一列绑定到SortedList的Key，第二列绑定到SortedList的键中对象的字段，例如

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        InitializeTable();
    }
    public void InitializeTable()
    {
        SortedList<DateTime, Dividend> EquityDividends = new SortedList<DateTime, Dividend>();
        EquityDividends.Add(new DateTime(2011, 1, 12, 16, 30, 00, DateTimeKind.Local), new Dividend(new DateTime(2011, 1, 12, 16, 30, 00, DateTimeKind.Local), "120", 12, new TimeSpan(4, 0, 0)));
        EquityDividends.Add(new DateTime(2011, 1, 13, 16, 30, 00, DateTimeKind.Local), new Dividend(new DateTime(2011, 1, 12, 16, 30, 00, DateTimeKind.Local), "125", 12, new TimeSpan(4, 0, 0)));
        gridControl1.DataSource = new BindingSource() { DataSource = EquityDividends };
        bandedGridView1.Columns[1].FieldName = "ExpectedDividend";
    }
}
public class Dividend
{
    public DateTime InDividendDate;
    public string ExpectedDividend;
    public double Adjustment;
    public TimeSpan TimeRemaining;
    public Dividend(
        DateTime InDividendDate,
        string ExpectedDividend,
        double Adjustment,
        TimeSpan TimeRemaining)
    {
        this.InDividendDate = InDividendDate;
        this.ExpectedDividend = ExpectedDividend;
        this.Adjustment = Adjustment;
        this.TimeRemaining = TimeRemaining;
    }
}

这不太管用（键出现在第0列，字符串"WindowsFormsApplication10.股息"出现在第1列）。有人有什么建议吗？

public override string ToString()
{
    return "MyValue";
}