private void btnLuu_Click(object sender, EventArgs e)
        {
            if (dpNgayLap.EditValue == null)
            {
                CheckLoi(lbNgayLap.Text);
                dpNgayLap.Focus();
            }
            if (lkNhanVien.EditValue == null)
            {
                CheckLoi(lkNhanVien.Text);
                lkNhanVien.Focus();
            }
            if (lkKhachHang.EditValue == null)
            {
                CheckLoi(lkKhachHang.Text);
                lkKhachHang.Focus();
            }
            bill bl = new bill();
            bl.created = (DateTime)dpNgayLap.EditValue;
            bl.id = txtMaHoaDon.Text;
            bl.type = "bg";
            customer c = (customer)lkKhachHang.GetSelectedDataRow();
            staff s = (staff)lkNhanVien.GetSelectedDataRow();
            bl.customer = c;
            bl.staff = s;

            if (busHoaDon.Save())
            {
                XtraMessageBox.Show("Lưu thành công", this.Text, MessageBoxButtons.OK, MessageBoxIcon.Information, MessageBoxDefaultButton.Button1);
                btnDanhMucLamMoi.PerformClick();
                txtMaHoaDon.Text = txtTongTien.Text = txtThue.Text = txtThanhToan.Text = null;
                dpNgayLap.EditValue = DateTime.Now;
                lkKhachHang.EditValue = lkNhanVien.EditValue = null;
                panelControl4.Enabled = false;
            }
            else
            {
                XtraMessageBox.Show("Lưu thất bại", this.Text, MessageBoxButtons.OK, MessageBoxIcon.Information, MessageBoxDefaultButton.Button1);
            }
        }
 public object GetProduct(bill b)
 {
     try
     {
         var bd = from d in b.bill_details
                  select d;
         return bd;
     }
     catch(Exception ex)
     {
         throw ex;
     }
 }
 private void gvPhieuBaoGia_FocusedRowChanged(object sender, DevExpress.XtraGrid.Views.Base.FocusedRowChangedEventArgs e)
 {
     if (gvPhieuBaoGia.SelectedRowsCount != 1)
         return;
     b = (bill)gvPhieuBaoGia.GetFocusedRow();
     txtMaHoaDon.Text = b.id;
     dpNgayLap.EditValue = b.created;
     lkKhachHang.EditValue = b.customer_id;
     lkNhanVien.EditValue = b.staff_id;
     btnLuu.Enabled = btnHuy.Enabled = btnThemKhachHang.Enabled = false;
 }
 public bool KiemTraTonTai(bill bl, product sp)
 {
     try
     {
         var p = from b in bl.bill_details
                 where b.product_id.Equals(sp.id)
                 select b;
         return p.Count() == 1;
     }
     catch (Exception ex)
     {
         throw ex;
     }
 }
 public bool Update(bill pbill)
 {
     try
     {
         pbill.modified = DateTime.Now;
         db.SubmitChanges();
         return true;
     }
     catch(Exception ex)
     {
         throw ex;
     }
 }
 partial void Deletebill(bill instance);
 public bool Insert(bill pbill)
 {
     try
     {
         db.bills.InsertOnSubmit(pbill);
         db.SubmitChanges();
         return true;
     }
     catch(Exception ex)
     {
         throw ex;
         //return false;
     }
 }
 partial void Updatebill(bill instance);
 partial void Insertbill(bill instance);
		private void detach_bills(bill entity)
		{
			this.SendPropertyChanging();
			entity.customer = null;
		}
		private void attach_bills(bill entity)
		{
			this.SendPropertyChanging();
			entity.customer = this;
		}
		private void attach_bills(bill entity)
		{
			this.SendPropertyChanging();
			entity.staff = this;
		}