I have 3 list boxes, the listBox_menu is where the items are first displayed if buttons (entrees, drinks, and sides) are clicked, then to add the items to order you select your item from the listBox_menu and click add to order to have it appear in the listBox_order. From there once the customer order is ready to be made the submit button will print out the customers name (textBox_name) and all the items in the listBox_order, and display it all in one line.

I'm just having trouble figuring out how to do that, if anyone could please help.

CodePudding user response：

First define two global variables, then use the CalculateTotalCost function (which I defined).

My answer has been updated.

Output (tested in Visual Studio 2017, .Net Framework 4.5.2):

These are my codes:

    public Form1()
    {
        InitializeComponent();
        listBox_menu.SelectionMode = SelectionMode.MultiExtended;
    }
    double Cost = 0;
    string Order = null;
    public double CalculateTotalCost(object input, bool Total)
    {
        if (Total == true)
        {
            switch (input)
            {
                case "Salad":
                    Cost  = 2500;
                    break;
                case "Rice":
                    Cost  = 3000;
                    break;
                case "non-alcoholic beer":
                    Cost  = 1000;
                    break;
                case "Water":
                    Cost  = 200;
                    break;
                case "Ex1":
                    Cost  = 2200;
                    break;
                default:
                    Cost  = 2200;
                    break;
            }
        }
        else
        {
            switch (input)
            {
                case "Salad":
                    Cost -= 2500;
                    break;
                case "Rice":
                    Cost -= 3000;
                    break;
                case "non-alcoholic beer":
                    Cost -= 1000;
                    break;
                case "Water":
                    Cost -= 200;
                    break;
                case "Ex1":
                    Cost -= 2200;
                    break;
                default:
                    Cost -= 2200;
                    break;
            }
        }
        return Cost;
    }
    private void Entrees_Click(object sender, EventArgs e)
    {
        listBox_menu.Items.Clear();
        listBox_menu.Items.Add("Salad");
        listBox_menu.Items.Add("Rice");
    }
    private void Drinks_Click(object sender, EventArgs e)
    {
        listBox_menu.Items.Clear();
        listBox_menu.Items.Add("non-alcoholic beer");
        listBox_menu.Items.Add("Water");
    }
    private void Sides_Click(object sender, EventArgs e)
    {
        listBox_menu.Items.Clear();
        listBox_menu.Items.Add("Ex1");
        listBox_menu.Items.Add("Ex2");
    }
    private void AddtoOrder_Click(object sender, EventArgs e)
    {
        if(listBox_menu.SelectedItems.Count>0)
        {
            for (int i = 0; i < listBox_menu.SelectedItems.Count; i  )
            {
                listBox_order.Items.Add(listBox_menu.SelectedItems[i].ToString());
                lblTotalCost.Text = (CalculateTotalCost(listBox_menu.SelectedItems[i].ToString(),true)).ToString();
            }
        }
    }
    private void RemoveFromOrder_Click(object sender, EventArgs e)
    {
        if (listBox_order.SelectedItems.Count > 0)
        {
            listBox_order.Items.Remove(listBox_order.SelectedItem);
        }
        Order = null;
        for (int i = 0; i < listBox_order.Items.Count; i  )
        {
            Order  = listBox_order.Items[i].ToString()   " , ";
        }
        Cost = 0;
        if (listBox_order.Items.Count > 0)
        {
            for (int i = 0; i < listBox_order.Items.Count; i  )
            {
                Cost = (CalculateTotalCost(listBox_order.Items[i], true));
            }
        }
        lblTotalCost.Text = Cost.ToString();
    }
    private void Submit_Click(object sender, EventArgs e)
    {
        MessageBox.Show("Customer name: "   txtBoxCustomerName.Text   " Orders: "   Order   " Total cost: "   Cost);
    }

Note: if this solution helps you, please mark as answer (don't forget to vote for me).

Thanks