主题：分页流水账的统计

不要用重置列，单独写一个代码计算，如

Dim dt As Datatable = DataTables("半成品流水")
Dim dic As new Dictionary(of String, Double)
For Each dr As DataRow In dt.Select("")
    Dim key = dr("半成品件号")
    If dic.ContainsKey(key) = False Then
        Dim dt1 As Integer = dt.sqlCompute("Sum(入库)","半成品件号 = '" & key & "'")
        Dim dt2 As Integer = dt.sqlCompute("Sum(出库)","半成品件号 = '" & key & "'")
        dr("库存") = dt1 - dt2
        dic.Add(key,  dt1 - dt2)
    Else
        dr("库存") = dic(key)
    End If
Next

关键是执行了多少次 sqlCompute 函数，每一次执行都是很耗时的。

或者试试改成下面这样，如果还是耗时，做具体实例发上来测试优化

systemready = false
Dim dt As Datatable = DataTables("半成品流水")
Dim dic As new Dictionary(of String, Double)
For Each dr As DataRow In dt.Select("")
    Dim key = dr("半成品件号")
    If dic.ContainsKey(key) = False Then
        Dim dt1 As Integer = dt.sqlCompute("Sum(入库)","半成品件号 = '" & key & "'")
        Dim dt2 As Integer = dt.sqlCompute("Sum(出库)","半成品件号 = '" & key & "'")
        dr("库存") = dt1 - dt2
        dic.Add(key,  dt1 - dt2)
    Else
        dr("库存") = dic(key)
    End If
Next
systemready = true