我无法让 textBox_name 文本和 listBox_order 项目在另一个列表框的一行中正确显示

I can't get the textBox_name text and listBox_order items to display correctly in one line on another listbox

我有 3 个列表框,如果单击按钮(主菜、饮料和配菜),listBox_menu 是首先显示项目的地方,然后添加要订购的项目 select您的商品来自 listBox_menu,然后单击“添加到订单”以使其显示在 listBox_order 中。一旦客户订单准备就绪,提交按钮将打印出客户姓名 (textBox_name) 和 listBox_order 中的所有项目,并将其全部显示在一行中。

我只是不知道该怎么做,如果有人能帮忙的话。

先定义两个全局变量,然后使用CalculateTotalCost函数(我定义的)

我的回答已更新。

输出(在 Visual Studio 2017.Net Framework 4.5.2 中测试):

这些是我的代码:

    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);
    }