Sử dụng DefaultView và Row RowFilter DataTable trong C#

namespace DemoDataTable

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        DataTable dtData = new DataTable();



        private void Form1_Load(object sender, EventArgs e)

        {

            KhoiTaoCauTruc();

            loadData();

        }

        private void KhoiTaoCauTruc()

        {

            // Khoi tao cau truc DataTable

            dtData.Columns.Add("TT", typeof(int));

            dtData.Columns.Add("Ten", typeof(String));

            dtData.Columns.Add("Lop", typeof(String));

            dtData.Columns.Add("Diem", typeof(int));

            //

        }

        private void loadData()

        {

            // cách 1

            dtData.Rows.Add(1,"Tran A","Lop A",2);

            dtData.Rows.Add(2, "Tran B", "Lop A", 5);



            // cách 2:

            DataRow drNew = dtData.NewRow();

            drNew["TT"] = 3;

            drNew["Ten"] = "Le Binh";

            drNew["Lop"] = "Lop B";

            drNew["Diem"] = 8;

            dtData.Rows.Add(drNew);

            //

            for(int i=4;i<=10;i++)

            {

                DataRow drAdd2 = dtData.NewRow();

                drAdd2["TT"] = 4;

                drAdd2["Ten"] = "Nguyen "+ i.ToString();

                drAdd2["Lop"] = "Lop C";

                drAdd2["Diem"] = 9 ;

                dtData.Rows.Add(drAdd2);

            }

            //

            dataGridView1.DataSource = dtData;

        }



        private void textBox1_TextChanged(object sender, EventArgs e)

        {   //5-   " OR (Diem>=5 AND Diem<=")";

            string nd = textBox1.Text;

            // 5-8:    {tudiem}=5  , {dendiem}=8

            string tudem = "0";

            string dendiem = "10";

            string where_diem = "";

            //

            if(nd.Contains("-"))

            {

                tudem = nd.Split('-')[0];

                dendiem = nd.Split('-')[1];

                if(dendiem!=string.Empty)

                    where_diem = " OR (Diem>="+tudem+" AND Diem<="+dendiem+")";

            }    

           

            DataView dv = dtData.DefaultView;

            dv.RowFilter = "Ten Like '%" + nd

                + "%' OR Lop Like '%" + nd + "%' "+ where_diem;

              



        }

    }

}