Question

我还是C＃的新手，我目前仍陷在一个项目中。所以基本上我目前有一个包含5个文本框，一个复选框和一个按钮的表单。当用户填写信息并提交而未选中复选框时，信息将存储在数组列表中。如果用户注册为火车驾驶员，并标记了火车驾驶员复选框并提交，则需要将“ id”以及所有其他信息（例如名字和姓氏等）传递到数组列表中。

目前，我有一个Person类，可以正常工作。然后，我有一个名为traindrivers的子类，该子类包含一个“ id”变量，每次注册新的Traindriver时，该变量都会“递增”，因为它们的编号不能相同。那么，如果已注册的人被标记为火车司机，我该如何将该“ id”添加到“ personsArrayList”中？

Form

我尝试使用添加新“个人”时所使用的过程。但是由于某种原因，我找不到包含ID的变量。

public class Persons
{
    //instance variables
    private string firstname;
    private string lastname;
    private string email;
    private int age;


    //constructor
    public Persons(string firstname, string lastname, string email, int age)
    {
        this.firstname = firstname;
        this.lastname = lastname;
        this.email = email;
        this.age = age;
    }

    public string FirstName
    {
        get { return firstname; }
        set { firstname = value; }
    }
    public string LastName
    {
        get { return lastname; }
        set { lastname = value; }
    }
    public string Email
    {
        get { return email; }
        set { email = value; }
    }
    public int Age
    {
        get { return age; }
        set { age = value; }
    }

    public override string ToString()
    {
        return FirstName + " " + LastName + " - " + Email + " - " + Age + ".";
    }

}

public class Traindrivers : Persons
{
    protected int id;
    protected static int mycounter;

    public Traindrivers(int id, string firstname, string lastname, string email, int age) : base(firstname, lastname, email, age)
    {
        mycounter++;
        id = mycounter;
    }


    public int LicensNumber
    {
        get { return id; }
        set { id = value; }
    }

    public override string ToString()
    {
        return LicensNumber + FirstName + LastName + Email + Age;
    }
}

----------- aspx页面---------

protected void Button1_Click(object sender, EventArgs e)
    {
        Persons p1 = new Persons(TextBoxFirstName.Text, TextBoxLastName.Text, TextBoxEmail.Text, Convert.ToInt32(TextBoxAge.Text));
        personsArrayList.Add(p1);

        //Session["trainpersons"] = personsArrayList;
    }

    protected void CheckBox1_CheckedChanged(object sender, EventArgs e)
    {
      // When the checkbox is marked, add "id" to the arraylist
    }

    protected void ShowButton_Click(object sender, EventArgs e)
    {
        ListBox1.Items.Clear();
        for (int i = 0; i < personsArrayList.Count; i++)
        {
            ListBox1.Items.Add(personsArrayList[i].ToString());
            Console.WriteLine(i);
        }
    }
}

protected void trainBtn_Click(object sender, EventArgs e)
    {
        ListBox1.Items.Clear();
        for (int i = 0; i < traindriversArrayList.Count; i++)
        {
            ListBox1.Items.Add(traindriversArrayList[i].ToString());
        }
    }

预期结果是，只要注册了火车司机，就添加“ id”。当然，它应该进入personArrayList。

Answer 1

在此新修改的基础上，一切正常，只需稍作更改即可。首先，您不需要任何计数器，静态ID就足够了，并且由于您要增加该ID，因此应该对其进行初始化。而且由于它将自动运行，因此无需将id用作参数

    public class Traindrivers : Persons
    {
        protected int id=0;
    //                   ^^
        protected static int mycounter=0;

        public Traindrivers(/*int id,*/ string firstname, string lastname, string email, int age) : base(firstname, lastname, email, age)
//                          ^^^^^^^^^
        {
            mycounter++;
            id = mycounter;
        }


        public int LicensNumber
        {
            get { return id; }
            set { id = value; }
        }

        public override string ToString()
        {
            return LicensNumber + FirstName + LastName + Email + Age;
        }
    }

当您要使用它时，请在Button1_Click方法中首先检查该复选框是否已选中，然后基于此进行操作，如下所示：

protected void Button1_Click(object sender, EventArgs e){
    if(CheckBox1.checked==true){//information is about a traindriver
            Traindrivers t1 = new Traindrivers (TextBoxFirstName.Text, TextBoxLastName.Text, TextBoxEmail.Text, Convert.ToInt32(TextBoxAge.Text));
            traindriversArrayList.Add(t1);
    }
    else{//information in textboxes is not about traindriver
            Persons p1 = new Persons(TextBoxFirstName.Text, TextBoxLastName.Text, TextBoxEmail.Text, Convert.ToInt32(TextBoxAge.Text));
            personsArrayList.Add(p1);
    }
}

如果选中了复选框，如何将“ item”添加到arraylist？

1 个答案: