private void LoadDSDoanVan()
 {
     dtgv_DoanVan.DataSource = BTDocDAO.LoadDSCauHoi();
     dtgv_DoanVan.Columns["Id_doc"].HeaderText  = "STT";
     dtgv_DoanVan.Columns["DoanVan"].HeaderText = "Nội dung đoạn văn";
     dtgv_DoanVan.Columns["Id_doc"].Width       = 50;
     dtgv_DoanVan.Columns["DoanVan"].Width      = 400;
 }
        private void btn_ADD_Click(object sender, EventArgs e)
        {
            List <BTNguPhap> listBTNP = BTNguPhapDAO.LoadDSCauHoi();
            int          Count_NP     = listBTNP.Count;
            List <BTDoc> listDOC      = BTDocDAO.LoadDSCauHoi();
            int          Count_Doc    = listDOC.Count;

            List <int> listNP_Check  = new List <int> ();
            List <int> listDOC_Check = new List <int>();

            while (listNP_Check.Count < int.Parse(txb_NP.Text))
            {
                Random rd     = new Random();
                int    number = rd.Next(0, Count_NP - 1);
                if (listNP_Check == null)
                {
                    listNP_Check.Add(number);
                }
                else
                {
                    while (listNP_Check.Contains(number))
                    {
                        number = rd.Next(0, Count_NP - 1);
                    }
                    listNP_Check.Add(number);
                }
            }
            while (listDOC_Check.Count < int.Parse(tx_DoanVan.Text))
            {
                Random rd     = new Random();
                int    number = rd.Next(0, Count_Doc - 1);
                if (listDOC_Check == null)
                {
                    listDOC_Check.Add(number);
                }
                else
                {
                    while (listDOC_Check.Contains(number))
                    {
                        number = rd.Next(0, Count_Doc - 1);
                    }
                    listDOC_Check.Add(number);
                }
            }
            MaDeThiDAO.Add(Txb_made.Text);
            foreach (int item in listNP_Check)
            {
                ChiTiet_NguPhapDAO.Add(MaDeThiDAO.GetIdCuoi(), listBTNP[item].Id_BTNguPhap);
            }
            foreach (int item in listDOC_Check)
            {
                ChiTiet_DocDAO.Add(MaDeThiDAO.GetIdCuoi(), listDOC[item].Id_Doc);
            }
            MessageBox.Show("Bạn đã tạo mới để thi thành công", "Thông báo");
            this.Hide();
        }