c# - 无法将不同的变量相加，即使值已更改

Question

所以我对编码真的很陌生，所以我边走边学。我正在为一门课程做作业，我必须为一家公司创建一个派对预订程序。这个想法很简单，只需选择一些不同的选项，将它们加起来，然后计算成本。我的标签会改变并显示变量设置为的整数，它们工作得很好，这会告诉我变量本身确实在改变。

但是，一旦我尝试将变量添加在一起，它就不起作用了。

public partial class AdultPayment : Form
{
    public static int ConvertNumberAdult = Convert.ToInt32(Adult.numberAdult);
    public static int MealCost = Adult.mealPrice*ConvertNumberAdult;
    private static int PrivateRoomCost;
    public static int TotalCost = MealCost + CalculateWine + PrivateRoomCost;        
    public static string DisplayNumberAdult = Convert.ToString(Adult.numberAdult);

    private static int CalculateWine { get; set; } = ConvertNumberAdult / 6 * 15;



    public AdultPayment()
    {

        InitializeComponent();

        lblAdultConfirmName.Text = Adult.adultContactName;
        lblAdultConfirmNumber.Text = Adult.adultContactNumber;
        lblAdultConfirmDate.Text = Adult.adultDate;
        lblAdultConfirmTime.Text = Adult.adultTime;
        lblConfirmNumberOfAdult.Text = Adult.numberAdult.ToString();
        lblMealCostTotal.Text = "£"+ MealCost.ToString();
        lblCostTotal.Text = "£" + TotalCost.ToString();

        if (Adult.adultPrivateRoom == true)
        {
            PrivateRoomCost = 40;
            lblAdultConfirmPrivateRoom.Text = "Yes";
            lblPrivateRoomTotal.Text = "£"+ PrivateRoomCost;
        }
        else
        {
            PrivateRoomCost = 0;
            lblAdultConfirmPrivateRoom.Text = "No";
            lblPrivateRoomTotal.Text = "N/A";                
        }

        if(Adult.menuOption == true)
        {
            lblConfirmMenu.Text = "2 Courses for £15 each";
        }
        if(Adult.menuOption == false)
        {
            lblConfirmMenu.Text = "3 Courses for £18 each";
        }
        
        if (Adult.addWine == false) 
        {
            CalculateWine = 0;
            lblConfirmWineAdded.Text = "No";
            lblWineTotal.Text = "N/A";
        }
        
        else
        {
            lblConfirmWineAdded.Text = "Yes";
            lblWineTotal.Text = "£"+ CalculateWine.ToString();
        }

        lblCostTotal.Text = "£" + TotalCost.ToString();

    }

}

我有一个不同的表格，它允许用户选择他们的偏好，这就像我需要的那样。应该将其他变量加在一起的变量是

public static int TotalCost = MealCost + CalculateWine + PrivateRoomCost;

我现在真的很困惑，因为我对此很陌生，所以我不知道该怎么说才能在互联网上找到任何东西

任何帮助都会很棒！

谢谢！

标签： c#visual-c#-express-2010