ASP.NET中Dataset的table数据合并、数据截取、数据排序

1、两个相同字段表的合并：

 public static DataSet CombineTables(DataSet _ds, DataTable _dt1, DataTable _dt2)
         {
             DataSet ds = _ds.Clone();
             //ds.Tables[0].Clone();
             ds.Tables[].Rows.Clear();
             int i = ;
             for ( i = ; i < _dt1.Rows.Count; i++)
             {
                 ds.Tables[].ImportRow(_dt1.Rows[i]);
             }
             for (int j = ; j < _dt2.Rows.Count; j++)
             {
                 ds.Tables[].ImportRow(_dt2.Rows[j]);
             }
             return ds;
         }

2、对表的数据截取：

 public static DataSet CopyScopeRows(DataSet source, int startRowNum, int endRowNum) {
             DataSet des = source.Clone();
             des.Tables[].Rows.Clear();
             for (int i = startRowNum; i < source.Tables[].Rows.Count && i <= endRowNum; i++) {
                 des.Tables[].ImportRow(source.Tables[].Rows[i]);
             }
             return des;
         }

3、数据行的筛选：

 public static DataSet CopyScopeRows(DataSet source, string filter) {
             DataSet des = source.Clone();
             DataSet _ds = null;
             des.Tables[].Rows.Clear();
             try
                 {
             DataRow[] rows = source.Tables[].Select(filter);
             foreach (DataRow row in rows) {
                 des.Tables[].ImportRow(row);
             }}
             catch (Exception ex) { return _ds; }
             finally
                 {}
             return des;
         }

4、数据行的筛选，并可以排序：

 public static DataSet CopyScopeRows(DataSet source, string filter, string order) {
             DataSet des = source.Clone();
             des.Tables[].Rows.Clear();
             DataRow[] rows = source.Tables[].Select(filter, order);
             foreach (DataRow row in rows)
             {
                 des.Tables[].ImportRow(row);
             }
             return des;
         }

5、数据行的筛选，并可截取数据行：

 public static DataSet CopyScopeRows(DataSet source, string filter, int startRowNum, int endRowNum) {
             DataSet des = source.Clone();
             des.Tables[].Rows.Clear();
             DataRow[] rows = source.Tables[].Select(filter);
             for (int i = startRowNum; i < rows.Length && i <= endRowNum; i++)
             {
                 des.Tables[].ImportRow(rows[i]);
             }
             return des;
         }

6、数据行的筛选、排序，并可截取数据行：

 public static DataSet CopyScopeRows(DataSet source, string filter, string order, int startRowNum, int endRowNum) {
             DataSet des = source.Clone();
             des.Tables[].Rows.Clear();
             DataRow[] rows = source.Tables[].Select(filter, order);
             for (int i = startRowNum; i < rows.Length && i <= endRowNum; i++) {
                 des.Tables[].ImportRow(rows[i]);
             }
             return des;
         }

 public static object GetValueByKey(DataTable table, string keyName, object keyValue, string returnName) {
             object obj = null;
             table.PrimaryKey = new DataColumn[] { table.Columns[keyName] };
             DataRow row = table.Rows.Find(keyValue);
             if (row != null) { obj = row[returnName]; }
             return obj;
         }

 public static object GetValueByKeys(DataTable table,  object[] keyValue, string returnName)
         {
             object obj = null;

             DataColumn[] keys = new DataColumn[];
             keys[] = table.Columns[];
             keys[] = table.Columns[];
             table.PrimaryKey = keys;

             DataRow row = table.Rows.Find(keyValue);
             if (row != null) { obj = row[returnName]; }
             return obj;
         }