加一列【累计实付金额】,然后显示累计结果,如
Dim drs As List(of DataRow)
Dim Filter As String
Dim d1 As Date = e.DataRow("付款日期")
d1 = new Date(d1.Year, d1.Month, 1)
Dim d2 As Date = d1.AddMonths(1)
Filter = "[付款日期] >= #" & d1 & "# and 付款日期 < #" & d2 & "# And [户名] = '" & e.DataRow("户名") & "'"
drs = e.DataTable.Select(Filter, "付款日期,_sortkey")
For Each dr As DataRow In drs
Filter = "[付款日期] <= #" & e.DataRow("付款日期") & "# and 付款日期 >= #" & d1 & "# And [户名] = '" & e.DataRow("户名") & "'"
Dim Val1 As Double = e.DataTable.Compute("Sum(实付金额)",Filter)
dr("累计实付金额") = Val1
Next