小编Dan*_*nny的帖子

我正在使用C#构建的Windows窗体应用程序出现问题.该错误表明"foreach语句不能对'CarBootSale.CarBootSaleList'类型的变量进行操作,因为'CarBootSale.CarBootSaleList'不包含'GetEnumerator'的公共定义".

我似乎无法理解造成这种情况的原因.

这是抛出错误的代码:

        List<CarBootSaleList> Sortcarboot = new List<CarBootSaleList>();

        foreach (CarBootSale c in carBootSaleList)
        {
            if (c.Charity == "N/A")
            {
                Sortcarboot.Add(carBootSaleList);
                textReportGenerator.GenerateAllReport(Sortcarboot, AppData.CHARITY);
            }
        }

这是CarBootSaleList类,它说没有GetEnumerator定义:

public class CarBootSaleList
{

    private List<CarBootSale> carbootsales;

    public CarBootSaleList()
    {
        carbootsales = new List<CarBootSale>();
    }

    public bool AddCarBootSale(CarBootSale carbootsale)
    {
        bool success = true;
        foreach (CarBootSale cbs in carbootsales)
        {
            if (cbs.ID == carbootsale.ID)
            {
                success = false;
            }
        }
        if (success)
        {
            carbootsales.Add(carbootsale);
        }
        return success;
    }

    public void DeleteCarBootSale(CarBootSale carbootsale)
    {
        carbootsales.Remove(carbootsale);
    } …

在我的表单加载,我有这个代码:

    private void Form1_Load(object sender, EventArgs e)
    {
        CharityCyclists cyclist1 = new CharityCyclists();
        CharityCyclists cyclist2 = new CharityCyclists("a", 1, "Finished", 0, 0, 0, "One Wheel", 1, 500);

        cyclist1.Type = "Novelty Charity Cyclist";
        cyclist1.Number = 1;
        cyclist1.Finished = "Not Finished";
        cyclist1.Hours = 0;
        cyclist1.Mins = 0;
        cyclist1.Secs = 0;
        cyclist1.Bicycle = "Tricycle";
        cyclist1.Wheels = 3;
        cyclist1.FundsRaised = 300;
    }

但是,我收到一条错误,说"'CycleEvent.CharityCyclists'不包含带0参数的构造函数",它说错误与代码的这一部分有关:

CharityCyclists cyclist1 = new CharityCyclists();

这是我的CharityCyclists类:

class CharityCyclists : Cyclists
{
    private string bicycle;
    private int wheels;
    private double fundsRaised;

    public …

我的Delphi程序构建和编译很好,但是一旦它在调试模式下运行,我得到以下错误;

属性ClientHeight不存在

在查看了所有.DFM文件源之后,每种形式的代码都在那里;

ClientHeight = 111

我不明白我哪里出错了？

我已经创建了一个程序,并对它进行了大量测试,我收到一条错误消息"FormatException未处理,输入字符串格式不正确".当我将任一文本框留空并按下"完成"按钮但如果我输入低于0或高于59的任何值 - 这是我想要允许的数字范围,它会正常工作.我怎么办？当盒子空白时,我没有收到这个错误？这是'btnFinished'背后的代码:

   private void btnFinished_Click(object sender, EventArgs e)
    {
        if (lstCyclists.SelectedIndex >= 0)
        {
            Cyclists currentCyc = (Cyclists)lstCyclists.SelectedItem;
            //Decalre the minsEntered and secsEntered variables for txtMins and textSecs
            int minsEntered = int.Parse(txtMins.Text);
            int secsEntered = int.Parse(txtSecs.Text);

            try
            {
                //If the status of a cyclist is already set to Finished, show an error
                if (currentCyc.Finished.ToString() == "Finished")
                {
                    MessageBox.Show("A time has already been entered for this cyclist");
                }
                else
                {
                    //if a minute lower than 0 or greater than 59 …

我正在尝试使用C#中的Windows窗体创建应用程序,但是我不断收到错误说明:

NullReferenceException未处理 - 对象引用未设置为对象的实例

它指向具有此代码的行:

carBootSaleList.AddCarBootSale(newCarBootSale);

我在表单界面上的方法:

  CarBootSaleList carBootSaleList;

  public void AddCarBootSale()
    {
        AddNewCarBootSale addForm = new AddNewCarBootSale();
        if (addForm.ShowDialog() == DialogResult.OK)
        {
            CarBootSale newCarBootSale = addForm.GetCarBootSaleData();

            carBootSaleList.AddCarBootSale(newCarBootSale);

            txtCarBootSale.Clear();
            txtCarBootSale.Text = newCarBootSale.Display();
        }
    }

CarBootSaleList类:

public class CarBootSaleList : IDisplay
{

    private List<CarBootSale> carbootsales;

    public CarBootSaleList()
    {
        carbootsales = new List<CarBootSale>();
    }

    public bool AddCarBootSale(CarBootSale carbootsale)
    {
        bool success = true;
        foreach (CarBootSale cbs in carbootsales)
        {
            if (cbs.ID == carbootsale.ID)
            {
                success = false;
            }
        }
        if (success)
        { …