Case "第二列","第二列前20行等于4的数量自动录入"
Dim dr As DataRow
Dim drs As List(of DataRow)
dr = e.DataTable.Find("[_SortKey] < " & e.DataRow("_SortKey"), "[_SortKey] Desc") '找出上一行
If dr Is Nothing Then '如果没有找到上一行,说明本行就是第一行
e.DataRow("第二列前20行等于4的数量自动录入") = Nothing
dr = e.DataRow
End If
drs = e.DataTable.Select("[_SortKey] <= " & dr("_SortKey"), "[_SortKey] desc")
dim sum as integer
For i As Integer = 0 To math.min(drs.Count - 1,19) '重算余下行的余额
If e.DataRow("第二列") = "4" Then sum += 1
next
e.DataRow("第二列前20行等于4的数量自动录入") = sum
End Select