主题：关于垂直表和水平表的转换

Dim dtb As New DataTableBuilder("表B")
 dtb.AddDef("部门名称",Gettype(String),10)
 dtb.AddDef("部门属性",Gettype(String),10)
 For Each v As String In DataTables("水平转换测试").GetValues("成本大类")
     dtb.AddDef(v & "_" & "本期金额", Gettype(Double))
     dtb.AddDef(v & "_" & "同期金额", Gettype(Double))
 Next
 dtb.Build()
For Each v As String() In DataTables("水平转换测试").GetValues("部门名称|部门属性")
     Dim dr1 As DataRow = DataTables("表B").AddNew()
     dr1("部门名称") = v(0)
     dr1("部门属性") = v(1)
     For Each dr2 As DataRow In DataTables ("水平转换测试").Select("部门名称 = '" & v(0) &  "' and 部门属性 = '" & v(1) &  "'")
         dr1(dr2("成本大类") & "_" & "本期金额") = dr2("本期金额")
         dr1(dr2("成本大类") & "_" & "同期金额") = dr2("同期金额")
     Next
 Next
DataTables("表B").DataCols.Add("合计_本期金额",Gettype(Double))
DataTables("表B").DataCols.Add("合计_同期金额",Gettype(Double))
Dim t As Table = Tables("表B")
Dim r As Row
For i As Integer = 0 To t.Rows.Count(True) - 1
    r = t.Rows(i,True)
     For Each v2 As String In DataTables("水平转换测试").GetValues("成本大类")
        r("合计_本期金额")=r(v2 & "_" & "本期金额")
Next
Next
MainTable = Tables("表B")

 当存在多个成本大类时， r("合计_本期金额")=r(v2 & "_" & "本期金额")只能合计到其中一个大类的值，如何才能合计到所有v2 & "_" & "本期金额"的值呢

改成

r("合计_本期金额") += r(v2 & "_" & "本期金额")