Public Overrides Function IsEditable( _
   ByVal row As Integer, _
   ByVal col As Integer _
) As Boolean

Dim instance As GroupDataModel
Dim row As Integer
Dim col As Integer
Dim value As Boolean
 
value = instance.IsEditable(row, col)

public override bool IsEditable( 
   int row,
   int col
)

private int GetYear(DateTime value)
{
return value.Year;
}

private int GetDecade(DateTime value)
{
int x = 0;
x = value.Year % 10;
x = value.Year - x;
return x;
}

<Serializable()>
public class MyGroupComparer1 : IComparer
{
private bool birthDate = true;

public MyGroupComparer1(bool bd)
{
birthDate = bd;
}

public int Compare(object x1, object y1)
{
int x;
int y;
x = 0;
y = 0;
if (birthDate)
{
if ((x1) is DateTime)
{
x = ((DateTime)(x1)).Year % 10;
x = ((DateTime)(x1)).Year - x;
}
if ((y1) is DateTime)
{
y = ((DateTime)(y1)).Year % 10;
y = ((DateTime)(y1)).Year - y;
}
}
else
{
if ((x1) is DateTime)
{
x = ((DateTime)(x1)).Year;
}
if ((y1) is DateTime)
{
y = ((DateTime)(y1)).Year;
}
}
if (x == y)
{
return 0;
}
else if (x > y)
{
return 1;
}
else
{
return -1;
}
}
}

void FpSpread1_Grouping(object sender, GroupingEventArgs e)
{
int c = e.SortInfo.Index;
FarPoint.Web.Spread.FpSpread ss = (FarPoint.Web.Spread.FpSpread)sender;
FarPoint.Web.Spread.Model.DefaultSheetDataModel dm;
if ((ss.ActiveSheetView.DataModel) is FarPoint.Web.Spread.Model.DefaultSheetDataModel)
{
    dm = (FarPoint.Web.Spread.Model.DefaultSheetDataModel)ss.ActiveSheetView.DataModel;
}
else
{
dm = (FarPoint.Web.Spread.Model.DefaultSheetDataModel)((FarPoint.Web.Spread.Model.GroupDataModel)ss.ActiveSheetView.DataModel).TargetModel;
}

c = dm.GetDataColumnFromModelColumn(c);
if (dm.GetDataView().Table.Columns[c].DataType.Equals(typeof(DateTime)))
{
if ((dm.GetDataView().Table.Columns[c].Caption.IndexOf("Birth") >= 0))
{
e.GroupComparer = new MyGroupComparer1(true);
}
else
{
e.GroupComparer = new MyGroupComparer1(false);
}
}
}

void FpSpread1_Grouped(object sender, EventArgs e)
{
FarPoint.Web.Spread.FpSpread ss = (FarPoint.Web.Spread.FpSpread)sender;
FarPoint.Web.Spread.Model.GroupDataModel gm;
if ((ss.ActiveSheetView.DataModel) is FarPoint.Web.Spread.Model.GroupDataModel)
{
gm = (FarPoint.Web.Spread.Model.GroupDataModel)ss.ActiveSheetView.DataModel;
if ((gm.GroupComparer) is MyGroupComparer1)
{
int i;
for (i = 0; i <= ss.ActiveSheetView.RowCount - 1; i++)
{
if (gm.IsGroup(i))
{
FarPoint.Web.Spread.Model.Group g;
g = gm.GetGroup(i);
if ((g.Rows[0]) is int & !(gm.IsEditable(i, g.Column))) 
{
string s = ss.ActiveSheetView.GetColumnLabel(0, ss.ActiveSheetView.GetViewColumnFromModelColumn(g.Column));
if (s.IndexOf("Birth") >= 0)
{
g.Text = s + ": " + GetDecade((DateTime)gm.TargetModel.GetValue((int)g.Rows[0], g.Column)) + "s";
}
else
{
g.Text = s + ": " + GetYear((DateTime)gm.TargetModel.GetValue((int)g.Rows[0], g.Column));
}
}
}
}
}
}
}

Private Function GetYear(ByVal value As DateTime) As Integer
Return value.Year
End Function

Private Function GetDecade(ByVal value As DateTime) As Integer
Dim x As Integer = 0
x = value.Year Mod 10
x = value.Year - x
Return x
End Function

<Serializable()> _
Public Class MyGroupComparer
Implements IComparer

Private birthDate As Boolean = True
Public Sub New(ByVal bd As Boolean)
birthDate = bd
End Sub

Public Function Compare(ByVal x1 As Object, ByVal y1 As Object) As Integer Implements System.Collections.IComparer.Compare

Dim x, y As Integer
x = 0
y = 0

If birthDate Then
If TypeOf (x1) Is DateTime Then
x = CType(x1, DateTime).Year Mod 10
x = CType(x1, DateTime).Year - x
End If
If TypeOf (y1) Is DateTime Then
y = CType(y1, DateTime).Year Mod 10
y = CType(y1, DateTime).Year - y
End If
Else
If TypeOf (x1) Is DateTime Then
x = CType(x1, DateTime).Year
End If
If TypeOf (y1) Is DateTime Then
y = CType(y1, DateTime).Year
End If
End If

If x = y Then
Return 0
ElseIf x > y Then
Return 1
Else
Return -1
End If
End Function

End Class

Protected Sub FpSpread1_Grouped(ByVal sender As Object, ByVal e As System.EventArgs) Handles FpSpread1.Grouped
Dim ss As FarPoint.Web.Spread.FpSpread = sender
Dim gm As FarPoint.Web.Spread.Model.GroupDataModel
If TypeOf (ss.ActiveSheetView.DataModel) Is FarPoint.Web.Spread.Model.GroupDataModel Then
gm = ss.ActiveSheetView.DataModel
If TypeOf (gm.GroupComparer) Is MyGroupComparer Then
Dim i As Integer
For i = 0 To ss.ActiveSheetView.RowCount - 1
If gm.IsGroup(i) Then
Dim g As FarPoint.Web.Spread.Model.Group
g = gm.GetGroup(i)
If TypeOf (g.Rows(0)) Is Integer And Not gm.IsEditable(i, g.Column) Is Integer Then
Dim s As String = ss.ActiveSheetView.GetColumnLabel(0, ss.ActiveSheetView.GetViewColumnFromModelColumn(g.Column))
If s.IndexOf("Birth") >= 0 Then
g.Text = s & ": " & GetDecade(gm.TargetModel.GetValue(g.Rows(0), g.Column)) & "s"
Else
g.Text = s & ": " & GetYear(gm.TargetModel.GetValue(g.Rows(0), g.Column))
End If
End If
End If
Next
End If
End If
End Sub

Protected Sub FpSpread1_Grouping(ByVal sender As Object, ByVal e As FarPoint.Web.Spread.GroupingEventArgs) Handles FpSpread1.Grouping
Dim c As Integer = e.SortInfo.Index
Dim ss As FarPoint.Web.Spread.FpSpread = sender
Dim dm As FarPoint.Web.Spread.Model.DefaultSheetDataModel
If TypeOf (ss.ActiveSheetView.DataModel) Is FarPoint.Web.Spread.Model.DefaultSheetDataModel Then
dm = ss.ActiveSheetView.DataModel
Else
dm = CType(ss.ActiveSheetView.DataModel, FarPoint.Web.Spread.Model.GroupDataModel).TargetModel
End If

c = dm.GetDataColumnFromModelColumn(c)
If dm.GetDataView().Table.Columns(c).DataType.Equals(GetType(DateTime)) Then
If dm.GetDataView().Table.Columns(c).Caption.IndexOf("Birth") >= 0 Then
e.GroupComparer = New MyGroupComparer(True)
Else
e.GroupComparer = New MyGroupComparer(False)
End If
End If
End Sub