为什么下列代码执行不完整

If e.DataCol.name = "单位" Then
    Dim dr As DataRow = e.DataRow
    Dim t As Table = Tables("Xxbb")
    Dim g As Subtotalgroup
    t.SubtotalGroups.Clear()
    t.GroupAboveData = False
    t.TreeVisible = False
    t.SpillNode = True
   
    g = New Subtotalgroup
    g.Aggregate = AggregateEnum.Sum
    g.GroupOn = "单位"
    g.TotalOn = "一年级,二年级,三年级,四年级,五年级,六年级"
    g.Caption = "{0} 小计"
    t.SubtotalGroups.Add(g)
   
    t.Subtotal()
    For i As Integer = 0 To Tables("Xxbb").Rows.Count(True) - 1 \'Count加上参数True
        If Tables("Xxbb").Rows(i,True).IsGroup Then \'如果是分组行
            If dr("单位") = Tables("Xxbb").Rows(i,True)("单位").SubString(0,4)  Then
                dr("SYBB") = Tables("Xxbb").Rows(i,True)("一年级")
            End If
        End If
    Next
   
End If

不在里面设置汇总后，把相单位相对应的数据调过来，可是有几个单位无数据