private void CalculateDayWage()
        {
            if (lv_Task.SelectedItems.Count != 1)
            {
                return;
            }
            wage   w       = lv_Task.SelectedItem as wage;
            double dayWage = 0;

            for (int i = 0; i < lv_Task.Items.Count; i++)
            {
                wage wt = lv_Task.Items.GetItemAt(i) as wage;
                if (w.Date == wt.Date)
                {
                    dayWage += wt.Wage;
                }
            }
            tb_DayWage.Text = dayWage.ToString();
        }
        private void FillListView()
        {
            string dateString = lst_Months.SelectedItem as string;

            dateString += "/01";
            DateTime pickedDate = new DateTime();

            try
            {
                pickedDate = DateTime.Parse(dateString);
            }
            catch
            {
                MessageBox.Show("Wrong date :" + dateString);
                return;
            }
            List <Value>  valueList  = new List <Value>();
            List <Assign> assginList = Db.QueryAssignByEmployeeId(LoginedEmployee.Id).ToList();
            List <wage>   wageList   = new List <wage>();

            foreach (Assign a in assginList)
            {
                ValuePrice p = Db.QueryValuePriceById(a.Price_Id).Single();
                Value      v = Db.QueryValueById(p.Value_Id).Single();
                if (v.TaskDate > pickedDate && v.TaskDate < pickedDate.AddMonths(1))
                {
                    wage w = new wage();
                    w.Count     = Db.QueryReckonByAssignId(a.Id).Single().Count;
                    w.Date      = v.TaskDate;
                    w.Price     = p.Unit_Price;
                    w.Procedure = Db.QueryProcedureById(p.Procedure_Id).Single().Name;
                    w.Product   = Db.QueryProductById(v.Product_Id).Single().Name;
                    w.Unit      = p.Unit;
                    w.Value     = v.Name;
                    w.Wage      = w.Price * w.Count;
                    wageList.Add(w);
                }
            }
            lv_Task.ItemsSource = wageList;
            CalculateMonthWage(wageList);
        }