private void MaterialNameCb_TextChanged(object sender, TextChangedEventArgs e)
        {
            String text = this.MaterialNameCb.Text.Trim();

            if (text.Length < 2)
            {
                isSelectMaterial = false;
                this.MaterialNameCb.IsDropDownOpen = false;
            }
            if (isSelectMaterial == true)
            {
                return;
            }
            if (text.Length >= 2)
            {
                List <Material> list = MaterialModel.IndistictSearchByNameORFirstCase(text);
                if (list.Count > 0)
                {
                    isSelectMaterial = true;
                }
                this.tempMaterials.Clear();
                foreach (var item in list)
                {
                    this.tempMaterials.Add(item.id, item);
                }
                this.MaterialNameCb.ItemsSource = this.tempMaterials.Values.ToList();
                if (this.MaterialNameCb.ItemsSource != null)
                {
                    this.MaterialNameCb.IsDropDownOpen = true;
                }
                else
                {
                    this.MaterialNameCb.IsDropDownOpen = false;
                }
            }
            else
            {
                this.MaterialNameCb.ItemsSource = App.tempMaterials.Values.ToList();
            }
        }