private void btnTHTimMaP_Click(object sender, EventArgs e)
        {
            if (txtTHTimMaP.Text == "")
            {
                HienThiDSTatCaPhieu();
            }
            else
            {
                errIntMaPhieu.SetError(txtTHTimMaP, "");
                if (!txtTHTimMaP.Text.All(char.IsDigit))
                {
                    errIntMaPhieu.SetError(txtTHTimMaP, "Mã Phiếu là số");
                    return;
                }
                PhieuMuonSachDAO pms = new PhieuMuonSachDAO();
                pms.MaPhieuMuon = int.Parse(txtTHTimMaP.Text);

                PhieuMuonSachBLL        phieumsBLL  = new PhieuMuonSachBLL();
                List <PhieuMuonSachDAO> dsphieumuon = phieumsBLL.TimPhieuTheoMa(pms);
                lvTHDSP.Items.Clear();
                foreach (PhieuMuonSachDAO pmsBLL in dsphieumuon)
                {
                    ListViewItem lvi = new ListViewItem(pmsBLL.MaPhieuMuon + "");
                    lvi.SubItems.Add(pmsBLL.TenNguoiMuonSach);
                    lvi.SubItems.Add(pmsBLL.TrangThai);
                    lvi.SubItems.Add(pmsBLL.NgayMuon.ToString());
                    lvi.SubItems.Add(pmsBLL.NgayDuKienTra.ToString());
                    lvi.SubItems.Add(pmsBLL.NgayTraSach.ToString());
                    lvi.SubItems.Add(pmsBLL.TenSach);
                    lvTHDSP.Items.Add(lvi);
                }
            }
            LoadText();
        }
        private void btnTimTheoMa_Click(object sender, EventArgs e)
        {
            errorTimMaPhieu.SetError(txtTimMaPhieu, "");
            if (txtTimMaPhieu.Text == "")
            {
                errorTimMaPhieu.SetError(txtTimMaPhieu, "Nhập Mã Phiếu Muốn Tìm");
                return;
            }
            errorIntMaPhieu.SetError(txtTimMaPhieu, "");
            if (!txtTimMaPhieu.Text.All(char.IsDigit))
            {
                errorIntMaPhieu.SetError(txtTimMaPhieu, "Mã Phiếu là số");
                return;
            }
            PhieuMuonSachDAO pms = new PhieuMuonSachDAO();

            pms.MaPhieuMuon = int.Parse(txtTimMaPhieu.Text);

            PhieuMuonSachBLL        phieumsBLL  = new PhieuMuonSachBLL();
            List <PhieuMuonSachDAO> dsphieumuon = phieumsBLL.TimPhieuTheoMa(pms);

            lvDSPhieuMuon.Items.Clear();
            foreach (PhieuMuonSachDAO pmsBLL in dsphieumuon)
            {
                ListViewItem lvi = new ListViewItem(pmsBLL.MaPhieuMuon + "");
                lvi.SubItems.Add(pmsBLL.TenNguoiMuonSach);
                lvi.SubItems.Add(pmsBLL.TenSach);
                lvi.SubItems.Add(pmsBLL.NgayMuon.ToString());
                lvi.SubItems.Add(pmsBLL.NgayDuKienTra.ToString());
                lvi.SubItems.Add(pmsBLL.NgayTraSach.ToString());
                lvDSPhieuMuon.Items.Add(lvi);
            }
            txtTimPhieuTheoTen.Text = "";
        }