如何对业务逻辑层的数据排序？

Question

我想对业务逻辑层的强类型dataset数据排序，但都出错。在业务逻辑层应该怎么排序？用ObjectDataSource又怎么排序？
以下是代码：
    public EZDData.ExamInfoDataTable GetExams(int ExamTypeID, string[,] Proportion, int Amount)
    {
        EZDData.ExamInfoDataTable NewExamInfos = new EZDData.ExamInfoDataTable();        for (int i = 0; i < Proportion.Length / 2; i++)
        {
            EZDData.ExamInfoDataTable examInfos = new EZDData.ExamInfoDataTable();
            examInfos = Adapter.GetExamInfoByExamLevel(Convert.ToInt32(Proportion[i, 1]), ExamTypeID, Proportion[i, 0]);            NewExamInfos.Merge(examInfos);
           
        }
        
        /*
        DataView dv = NewExamInfos.DefaultView;
        dv.Sort = "ExamLevel desc";
        dv.Table.AcceptChanges();        EZDData.ExamInfoDataTable new_ExamInfos = new EZDData.ExamInfoDataTable();
        new_ExamInfos = dv.Table.Copy();
        */
        //NewExamInfos = dv.ToTable()        //NewExamInfos.DefaultView.Sort = "ExamLevel desc";
        //NewExamInfos.AcceptChanges();        return NewExamInfos;
    }new_ExamInfos = dv.Table.Copy();　会报错NewExamInfos = dv.ToTable()　也会报错

Answer 1

可以试一试：将其中转一下， GridView1.DataSource = dv; 在将GridView 给 datatable

Answer 2

dv.Sort = "ExamLevel desc"; 
这句可能有误

Answer 3

类型不匹配？
EZDData.ExamInfoDataTable是什么类型？把DataView转换成EZDData.ExamInfoDataTable类型。

Answer 4

NewExamInfos.DefaultView.Sort = " order by ExamLevel desc ";
NewExamInfos.AcceptChanges(); 

Answer 5

/**//// <summary>
        /// 从GridView的数据生成DataTable
        /// </summary>
        /// <param name="gv">GridView对象</param>
        public static DataTable GridView2DataTable(GridView gv)
        {
            DataTable table = new DataTable();
            int rowIndex = 0;
            List<string> cols = new List<string>();
            if (!gv.ShowHeader && gv.Columns.Count == 0)
            {
                return table;
            }
            GridViewRow headerRow = gv.HeaderRow;
            int columnCount = headerRow.Cells.Count;
            for (int i = 0; i < columnCount; i++)
            {
                string text = GetCellText(headerRow.Cells[i]);
                cols.Add(text);
            }
            foreach (GridViewRow r in gv.Rows)
            {
                if (r.RowType == DataControlRowType.DataRow)
                {
                    DataRow row = table.NewRow();
                    int j = 0;
                    for (int i = 0; i < columnCount; i++)
                    {
                        string text = GetCellText(r.Cells[i]);
                        if (!String.IsNullOrEmpty(text))
                        {
                            if (rowIndex == 0)
                            {
                               string columnName = cols[i];
                                if (String.IsNullOrEmpty(columnName))
                                {        
                                        continue;
                                }
                                if (table.Columns.Contains(columnName))
                                {
                                    continue;
                                }
                                DataColumn dc = table.Columns.Add();
                                dc.ColumnName = columnName;
                                dc.DataType = typeof(string);
                            }
                            row[j] = text;
                            j++;
                        }                    
                    }
                    rowIndex++;
                    table.Rows.Add(row);
                }
            }
            return table;
        }

Answer 6

NewExamInfos.DefaultView.Sort = " order by ExamLevel desc "; 

Answer 7

NewExamInfos.DefaultView.Sort = " order by ExamLevel desc "; 
NewExamInfos.AcceptChanges(); 我改成上面的代码会提示出错异常详细信息: System.IndexOutOfRangeException: 无法找到列 order by ExamLevel。

Answer 8

EZDData.ExamInfoDataTable 是强数据集类型，在底层DAL定义的。
把DataView转换成EZDData.ExamInfoDataTable类型　到底怎么转换啊？

Answer 9

我是要把　NewExamInfos　按照　ExamLevel排序后再在GridView显示出来，该怎么处理各位大侠！