主题：每次打开表都锁定表

下面代码有错误的地方吗？为什么数据表一打开就锁定表了呢？

表时间DataColChanged

 Select Case e.DataCol.Name
    Case  "实际用车日期_起","实际用车日期_止"
        Dim dr  As  DataRow = e.DataRow
        If dr.IsNull("实际用车日期_起") OrElse dr.IsNull("实际用车日期_止") Then
            dr("实际用车日期_天数") = Nothing
        Else
            Dim tp As TimeSpan = dr("实际用车日期_止") - dr("实际用车日期_起")
            dr("实际用车日期_天数")= tp.TotalDays + 1
        End  If
    End  Select
    Select Case e.DataCol.name
        Case  "用车时间_上车时间","用车时间_下车时间"
            Dim dr As DataRow = e.DataRow
            If dr.IsNull("用车时间_上车时间") Or dr.IsNull("用车时间_下车时间") Then
                dr("总工时") = Nothing
            Else
                Dim  tp As TimeSpan
                tp = dr("用车时间_下车时间") - dr("用车时间_上车时间")
                dr("总工时") = tp.TotalSeconds()
            End  If
        End  Select
       
        If e.DataCol.Name = "实际用车日期_起" Then
            If e.DataRow.IsNull("实际用车日期_起") Then
                e.DataRow("订单编号") = Nothing
            Else
                Dim bh As String = Format(e.DataRow("实际用车日期_起"),"yyyyMMdd")
                If e.DataRow("订单编号").StartsWith(bh) = False
                    Dim max As String
                    Dim idx As Integer
                    max = e.DataTable.Compute("Max(订单编号)","实际用车日期_起 = #" & e.DataRow("实际用车日期_起") & "# And [_Identify] <> " & e.DataRow("_Identify"))
                    If max > "" Then
                        idx = CInt(max.Substring(9,3)) + 1
                    Else
                        idx = 1
                    End If
                    e.DataRow("订单编号") = bh & "-" & Format(idx,"000")
                End If
            End If
        End If
       
        If e.DataRow("锁定本行") <> Nothing Then
            e.DataRow.Locked = False
        Else
            e.DataRow.Locked = True
        End If