您必须检查：

 _dt.DefaultView.RowStateFilter

我觉得默认的设置将不显示已删除的行，也许你的地方改变它。

I think that the default setting won't show deleted rows, maybe you change it somewhere.

您可以随时创建一个额外的RowView并控制其过滤器，做你的遍历视图。

You can always create an extra RowView and control its filter and do your loop over the View.