datatable 的select 方法的问题

Question

            //dtAll为全部数据
            DataTable dtFilter = dtAll.Copy(); 
           
            List<DataRow> listRow = new List<DataRow>();
            //listAll为我在dgv中选中行的数据
            foreach (Cost_FeeInfo cost in listAll) 
            {
                DataRow[] drSelect =dtAll.Select("BusinessNum='" + cost.BusinessNum  + "' and CostName='"+cost.CostName+"'");
                listRow.AddRange(drSelect);
            }
            foreach (DataRow dr in listRow) 
            {
                dtFilter.Rows.Add(dr);
            }问题是 我如何把我dtAll.select方法获得的数据添加到一个新的datatable
求高手解答

Answer 1

 static void Main(string[] args)
        {
            DataTable dt = MakeParentTable();
            DataTable dt2 = MakeNullTable();
            DataTable dt3 = new DataTable();
            dt.Select("id=1").ToList().ForEach(x =>
            {                DataRow row = dt2.NewRow();
                row["id"] = x["id"];
                row["ParentItem"] = x["ParentItem"];
                dt2.Rows.Add(row);
            });
            Console.WriteLine(dt2.Rows[0]["id"].ToString());
            Console.Read();
        }        public static DataTable MakeParentTable()
        {
            // Create a new DataTable.
            System.Data.DataTable table = new DataTable("ParentTable");
            // Declare variables for DataColumn and DataRow objects.
            DataColumn column;
            DataRow row;
            DataSet dataSet;            // Create new DataColumn, set DataType,  
            // ColumnName and add to DataTable.    
            column = new DataColumn();
            column.DataType = System.Type.GetType("System.Int32");
            column.ColumnName = "id";
            column.ReadOnly = true;
            column.Unique = true;
            // Add the Column to the DataColumnCollection.
            table.Columns.Add(column);            // Create second column.
            column = new DataColumn();
            column.DataType = System.Type.GetType("System.String");
            column.ColumnName = "ParentItem";
            column.AutoIncrement = false;
            column.Caption = "ParentItem";
            column.ReadOnly = false;
            column.Unique = false;
            // Add the column to the table.
            table.Columns.Add(column);            // Make the ID column the primary key column.
            DataColumn[] PrimaryKeyColumns = new DataColumn[1];
            PrimaryKeyColumns[0] = table.Columns["id"];
            table.PrimaryKey = PrimaryKeyColumns;            // Instantiate the DataSet variable.
            dataSet = new DataSet();
            // Add the new DataTable to the DataSet.
            dataSet.Tables.Add(table);            // Create three new DataRow objects and add  
            // them to the DataTable 
            for (int i = 0; i <= 4; i++)
            {
                row = table.NewRow();
                row["id"] = i;
                row["ParentItem"] = "ParentItem " + i;
                table.Rows.Add(row);
            }            return dataSet.Tables[0];
        }        public static DataTable MakeNullTable()
        {
            System.Data.DataTable table = new DataTable("ParentTable");
            // Declare variables for DataColumn and DataRow objects.
            DataColumn column;
            DataRow row;
            DataSet dataSet;            // Create new DataColumn, set DataType,  
            // ColumnName and add to DataTable.    
            column = new DataColumn();
            column.DataType = System.Type.GetType("System.Int32");
            column.ColumnName = "id";
            column.ReadOnly = true;
            column.Unique = true;
            // Add the Column to the DataColumnCollection.
            table.Columns.Add(column);            // Create second column.
            column = new DataColumn();
            column.DataType = System.Type.GetType("System.String");
            column.ColumnName = "ParentItem";
            column.AutoIncrement = false;
            column.Caption = "ParentItem";
            column.ReadOnly = false;
            column.Unique = false;
            // Add the column to the table.
            table.Columns.Add(column);            // Make the ID column the primary key column.
            DataColumn[] PrimaryKeyColumns = new DataColumn[1];
            PrimaryKeyColumns[0] = table.Columns["id"];
            table.PrimaryKey = PrimaryKeyColumns;
            return table;
        }
代码直接从msdn上copy过来的

Answer 2

DataTable dtAll=CreateDataTable();
//筛选年龄大于20的集合后添加到新的DataTable 中
                DataTable newDataTable = dtAll.Select("age>20").CopyToDataTable();

Answer 3

var rows = from row in dtAll.AsEnumerable().Select(item => item.Field<string>("BusinessNum") == cost.BusinessNum  && item.Field<string>("CostName=") == cost.CostName)
   select row;
dtFilter.Rows.Add(rows);

Answer 4

var rows = from row in dtAll.Select(string.Format("BusinessNum={0} and CostName={1}", cost.BusinessNum, cost.CostName))
   select row;
dtFilter.Rows.Add(rows);

Answer 5

DataTable dtFilter = dtAll.Clone();
var rows = dtAll.Select(string.Format("BusinessNum='{0}' and CostName='{1}'", cost.BusinessNum, cost.CostName));
dtFilter.Rows.Add(rows);

Answer 6

如果你的新的datatable里面没有数据，按二楼的来，如果你新的datatable里面有数据,并且框架和之前的相同则做如下处理：
DataTable dtAll=CreateDataTable();//筛选年龄大于20的集合后添加到新的DataTable中DataTable newDataTable.Merge(dtAll.Select("age>20").CopyToDataTable());

Answer 7

如果你的新的datatable里面没有数据，按二楼的来，如果你新的datatable里面有数据,并且框架和之前的相同则做如下处理：DataTable dtAll=CreateDataTable();//筛选年龄大于20的集合后添加到新的DataTable中
newDataTable.Merge(dtAll.Select("age>20").CopyToDataTable());