If e.DataRow("收款总额") IsNot Nothing Then
    Dim Sum1 As Double
    Dim Sum2 As Double
    Dim Sum3 As Double
    Sum1 = DataTables("收款明细表").Compute("Sum(收款总额)", "客户名称=\'" & e.DataRow("客户名称") & "\'")
    Sum2 = DataTables("合同一览表").Compute("Sum(合同总价款)", "客户名称=\'" & e.DataRow("客户名称") & "\'")
    Sum3=DataTables("历史结余明细").Compute("Sum(金额)", " 客户名称= \'" & e.DataRow("客户名称") & "\'and 年份=\'" & Date.now.year -1 & "\'")
    Dim Sum4 =Sum1-Sum3
    If Sum4< Sum2 Then
        Dim vrs As List(Of DataRow)
        vrs = DataTables("合同一览表").Select("[客户名称]=\'" & e.DataRow("客户名称") & "\'","合同日期 DESC")
        For n As Integer = vrs.Count - 1 To 0
            Dim Sum5 As Double
            Sum5=Sum5 + vrs(n)("合同总价款")
            If Sum5 > Sum4 then

               当前记录和剩下记录的“执行完毕”=否

              elseif Sum5 = Sum4 then

               剩下记录的“执行完毕”=否

            Exit For
            End If
        Next
    ElseIf Sum4= Sum2 Then
        MessageBox.show("该客户货款已全部结清","提示")
    Else
        MessageBox.show("该客户货款已全部结清,并有结余!","提示")
    End If
End If

红色部分也不知道思路对不对，帮忙改正，谢谢！

For n As Integer = vrs.Count - 1 To 0 Step -1
    Dim Sum5 As Double
    Sum5=Sum5 + vrs(n)("合同总价款")
    If Sum5 > Sum4
        For i As Integer = n To 0 Step -1
            vrs(i)("执行完毕") = "否"
           
        Next
        Exit For
    ElseIf Sum5 = Sum4
        For i As Integer = n+1 To 0 Step -1
            vrs(i)("执行完毕") = "否"
           
        Next
        Exit For
    End If
Next

 Sum2 = DataTables("合同一览表").Compute("Sum(合同总价款)", "客户名称=\'" & e.DataRow("客户名称") & "\'")
这句话少了一个条件：合同日期的年份=date。now。year

不知道该怎么写？，想写成tr（“合同日期”）。year ，dim 变量tr 为datarow 好像不行

日期的条件，参考

http://www.foxtable.com/help/topics/2720.htm

红袍兄：还有一个问题，vrs = DataTables("合同一览表").Select("[客户名称]=\'" & e.DataRow("客户名称") & "\'","合同日期 DESC")

那么，同一个客户同一天的合同，系统默认的是如何排序的呢？

因为上述代码，好像执行的不是很好，即便是收款额远大于今年合同款和去年结余，那些合同记录好像还是“否”

你可以根据合同日期、客户名称排序啊， 不行，就上传具体例子说明逻辑

合同日期 DESC,客户名称

想再填写红色部分的代码

For n As Integer = vrs.Count - 1 To 0 Step -1
    Dim Sum5 As Double
    Sum5=Sum5 + vrs(n)("合同总价款")
    If Sum5 > Sum4
        For i As Integer = vrs.Count - 1 To n step -1
            vrs(i)("执行完毕") = "否"
           
        Next
        Exit For
    ElseIf Sum5 = Sum4
        For i As Integer = vrs.Count - 1 To n-1 step -1
            vrs(i)("执行完毕") = "否"
           
        Next
        Exit For
    End If
Next