主题：逻辑值

Dim t As Row = Tables("收购").current()
Dim Total As Integer
Dim Amount As Double
With Tables("收购.销售")
    Total = .Compute("Sum(份数)")
    Amount = .Compute("Sum(重量)")
End With
Total = t("头数") - Total
Amount = t("重量") - Amount
If Total = 0 And Amount = 0 Then
    For Each t1 As Row In Tables("收购")
        If t1.Isnull("重量")  Then
            t1("销售已录入") = False
        Else
            t1("销售已录入") = True
        End If
    Next
   
    For Each t2 As Row In Tables("收购.销售")
        If t2.Isnull("重量")  Then
            t2("修改") = False
        Else
            t2("修改") = True
        End If
    Next
   
    With Tables("收购")
        .Position = .Rows.Count - 1
    End With
    Forms("录入销售").Close()
    Forms("录入窗口").Open()
Else
   
    MessageBox.Show("与收购不符,请修改收购!")
   
End If

为什么“销售已录入”逻辑不能正确显示？造成录入一行选true，下一行也选true.