主题：关联与增加行导致崩溃退出的问题

Select Case e.DataCol.Name
    Case "订单编号"
        If e.DataRow.IsNull("订单编号") = False Then '如果已经输入订单编号
            If e.DataRow.GetChildRows("订单明细").Count = 0 Then '而且无订单明细
                systemready = False
                Dim dr As DataRow = DataTables("订单明细").AddNew()
                dr("订单编号") = e.DataRow("订单编号")
                systemready = True
            End If
        End If
End Select

 主表删除代码

If e.DataRow.GetChildRows("订单明细").Count > 0 Then
    Dim s As String = "此订单存在订单明细, 是否确定要删除此订单及其订单明细?"
    If MessageBox.Show(s,"提示",MessageBoxButtons.YesNo,MessageBoxIcon.Question) = DialogResult.No
        e.Cancel= True
    Else
        systemready = False
        DataTables("订单明细").DeleteFor("单号 = '" & e.DataRow("单号") & "'")
        systemready = True
    End If
End If