以特定格式附加

Question

我需要以下格式 S_subno-brandno，brandno_subno-brandno

        deptBrandListName = cmbChannel.SelectedItem.ToString().Split('-')[0].Trim() +"_"+"sdfs";

        for (int i = 0; i < chklstBrandList.Items.Count; i++)
        {
            subNo[i] = chklstBrandList.Items[i].ToString().Split('-')[0];
        }

        for (int i = 0; i < chklstBrandList.Items.Count; i++)
        {
            brandNumber[i] = chklstBrandList.Items[i].ToString().Split('-')[1];
        }