Form1.vb

Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Windows.Forms
Imports DevExpress.XtraGrid.Columns

Namespace WindowsApplication1

    Public Partial Class Form1
        Inherits Form

        Private _KeyField As DataColumn

        Private _Tbl As DataTable

        Private _Cache As MyCache = New MyCache("ID")

        Private Function CreateTable(ByVal RowCount As Integer) As DataTable
            _Tbl = New DataTable()
            _KeyField = _Tbl.Columns.Add("ID", GetType(Integer))
            _KeyField.ReadOnly = True
            _KeyField.AutoIncrement = True
            _Tbl.Columns.Add("Name", GetType(String))
            _Tbl.Columns.Add("Number", GetType(Integer))
            _Tbl.Columns.Add("Date", GetType(Date))
            For i As Integer = 0 To RowCount - 1
                _Tbl.Rows.Add(New Object() {Nothing, String.Format("Name{0}", i), 3 - i, Date.Now.AddDays(i)})
            Next

            Return _Tbl
        End Function

        Public Sub New()
            InitializeComponent()
            gridControl1.DataSource = CreateTable(20)
            CreateUnboundColumn()
        End Sub

        Private Sub CreateUnboundColumn()
            Dim col As GridColumn = gridView1.Columns.AddVisible("Unbound", "Unbound column")
            col.UnboundType = DevExpress.Data.UnboundColumnType.String
        End Sub

        Private Sub gridView1_CustomUnboundColumnData(ByVal sender As Object, ByVal e As DevExpress.XtraGrid.Views.Base.CustomColumnDataEventArgs)
            If e.IsGetData Then e.Value = _Cache.GetValue(e.Row)
            If e.IsSetData Then _Cache.SetValue(e.Row, e.Value)
        End Sub
    End Class
End Namespace