Question

我正在使用HeadFirst C＃Book进行教程。表单本身之前是工作但现在它不是，我不记得我改变了什么。我现在已经多次翻过文本了，它似乎是一个逐字的副本，但它不起作用。我究竟做错了什么？我想问题必须在Form.cs文件中。

这是该课程的代码。

    class DinnerParty
    {
        public const int CostOfFoodPerPerson = 25;

        //declare DinnerParty automatic properties
        public int NumberOfPeople { get; set; }
        public bool HealthyOption { get; set; }
        public bool FancyDecorations { get; set; }

        // Setup Object Constructor with parameters masking the properties
        public DinnerParty(int numberOfPeople, bool healthyOption, bool fancyDecorations)
        {
            //Set Property Values to parameter values
            NumberOfPeople = numberOfPeople;
            HealthyOption = healthyOption;
            FancyDecorations = fancyDecorations;


        }

        //  Use private methods to access public properties bound to the form.

        private decimal CalculateCostOfBeveragesPerPerson()
        {
            decimal costOfBeveragesPerPerson;
            if (HealthyOption)
            {
                costOfBeveragesPerPerson = 5.00M;
            }
            else
            {
                costOfBeveragesPerPerson = 20.00M;
            }
            return costOfBeveragesPerPerson;
        }


        protected decimal CalculateCostOfDecorations()
        {
            decimal costOfDecorations;
            if (FancyDecorations)
            {
                costOfDecorations = (NumberOfPeople * 15.00M) + 50M;
            }
            else
            {
                costOfDecorations = (NumberOfPeople * 7.50M) + 30M;
            }
            return costOfDecorations;
        }

        //declare read only Cost property to be bound to costLabel control
        public decimal Cost
        {
            get
            {
                decimal totalCost = CalculateCostOfDecorations();
                totalCost += ((CalculateCostOfBeveragesPerPerson() + CostOfFoodPerPerson) * NumberOfPeople);
                if (HealthyOption)
                {
                    totalCost *= .95M;
                }
                return totalCost;
            }
        }
    }
}

这是表单的代码。

namespace DinnerParty
{
    public partial class Form1 : Form
    {
        DinnerParty dinnerParty;

        public Form1()
        {
            InitializeComponent();
            //Initialize DinnerParty object. Initialize DinnerParty party with      default form values.
            dinnerParty = new DinnerParty((int) numericUpDown1.Value, healthyBox.Checked , fancyBox.Checked);
            DisplayDinnerPartyCost();
        }

        // Bind form controls to DinnerParty Properties
        private void numericUpDown1_ValueChanged(object sender, EventArgs e)
        {
           dinnerParty.NumberOfPeople = (int)numericUpDown1.Value;
            DisplayDinnerPartyCost();
        }

        private void fancyBox_CheckedChanged(object sender, EventArgs e)
        {
            dinnerParty.FancyDecorations = fancyBox.Checked;
            DisplayDinnerPartyCost();

        } 

        private void healthyBox_CheckedChanged(object sender, EventArgs e)
        {
            dinnerParty.HealthyOption = healthyBox.Checked;
            DisplayDinnerPartyCost();
        }

        private void DisplayDinnerPartyCost()
        {
            decimal Cost = dinnerParty.Cost;
            costLabel.Text = Cost.ToString("c");
        }
    }
}

Answer 1

代码中的以下行可能有误。我没有看到任何课程DinnerParty2。将其更改为DinnerParty

 dinnerParty = new DinnerParty2((int) numericUpDown1.Value,   healthyBox.Checked , fancyBox.Checked);

Answer 2

根据评论，如果您要复制代码，请确保在设计器中再次连接事件处理程序，或手动：

healthyBox.CheckedChanged += healthyBox_CheckedChanged;

因为复制和粘贴控件时，不包括事件处理程序。

如何正确绑定属性以形成事件？

2 个答案: