//this method will clear/reset form values
private void CleanUp()
{
//shopping cart = a new empty list
ShoppingCart = new List<Product>();
//Textboxes and labels are set to defaults
TxtProdCode.Text = string.Empty;
txtQty.Text = string.Empty;
lbtotal.Content = "Total: $0.00";
//DataGrid items are set to null
CartGrid.ItemsSource = null;
CartGrid.Items.Refresh();
//Tmp variable is erased using null
tmpProduct = null;
}
private void Button_Click(object sender, RoutedEventArgs e)
{
//we first check if a product has been selected
if (tmpProduct == null)
{
//if not we call the search button method
Button_Click_1(null, null);
//we check again if the product was found
if (tmpProduct == null)
{
//if tmpProduct is empty (Product not found) we exit the procedure
MessageBox.Show("No product was selected", "No product", MessageBoxButton.OK,
MessageBoxImage.Exclamation);
//exit procedure
return;
}
}
//product quantity
int qty;
// we try to parse the number of the textbox if the number is invalid
int.TryParse(txtQty.Text, out qty);
//if qty is 0 we assign 0 otherwise we assign the actual parsed value
qty = qty == 0 ? 1 : qty;
//really basic validation that checks inventory
if (qty <= tmpProduct.Qty)
{
//we check if product is not already in the cart if it is we remove the old one
ShoppingCart.RemoveAll(s => s.Id == tmpProduct.Id);
//we add the product to the Cart
ShoppingCart.Add(new Product()
{
Id = tmpProduct.Id,
Name = tmpProduct.Name,
Price = tmpProduct.Price,
Qty = qty
});
//perform query on Shopping Cart to select certain fields and perform subtotal operation
BindDataGrid();
//<----------------------
//cleanup variables
tmpProduct = null;
//once the products had been added we clear the textbox of code and quantity.
TxtProdCode.Text = string.Empty;
txtQty.Text = string.Empty;
//clean up current product label
cprod.Content = "Current product N/A";
}
else
{
MessageBox.Show("Not enough Inventory", "Inventory Error", MessageBoxButton.OK,
MessageBoxImage.Exclamation);
}
}
private void Button_Click_1(object sender, RoutedEventArgs e)
{
//If a product code is not empty we search the database
if (Regex.IsMatch(TxtProdCode.Text.Trim(), @"^\d+$"))
{
DBInvoiceSample db = new DBInvoiceSample();
//parse the product code as int from the TextBox
int id = int.Parse(TxtProdCode.Text);
//We query the database for the product
Product p = db.Products.SingleOrDefault(x => x.Id == id);
if (p != null) //if product was found
{
//store in a temp variable (if user clicks on add we will need this for the Array)
tmpProduct = p;
//We display the product information on a label
cprod.Content = string.Format("ID: {0}, Name: {1}, Price: {2}, InStock (Qty): {3}", p.Id, p.Name, p.Price, p.Qty);
}
else
{
//if product was not found we display a user notification window
MessageBox.Show("Product not found. (Only numbers allowed)", "Product code error", MessageBoxButton.OK, MessageBoxImage.Exclamation);
}
}
}