C# 运行FOR循环，从默认构造函数c创建4个水管工#

正如您在上面的标题中看到的，我需要运行FOR循环，从默认构造函数创建4个水管工。创建后（在FOR循环中），更改其名称，将其添加到员工列表并显示在列表框中。所以基本上，水管工实际上是在另一个叫做EmployeeList的类中声明的列表。Wehn我试着把他们的名字改成随机的，我得到了一个错误消息，说“索引超出范围”。有人能帮我吗

表格代码

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    //create class-level employee list 
    EmployeeList plumbers = new EmployeeList();

    private void Form1_Load(object sender, EventArgs e)
    {
        //run a for loop to create 4 plumbers from the default constructor.
        for (int i = 0; i < plumbers.Count; i++)
            plumbers[i] = new Employee();

        //After they are created (within the FOR loop), change their names, 
        //plumbers[0].Name = "Nicole Fernandez";

        //add them to the employee list  

        //display in listbox
        foreach (Employee item in plumbers.Employees)
        { 
            lstDisplay.Items.Add(item.DisplayData());
        }
    }

class EmployeeList
{
    //use private access modifier to create a list of employee
    private List<Employee> employees = new List<Employee>();

    public List<Employee> Employees
    {
        get { return employees; }
        set { employees = value; }
    }

    //return the count of the employee list, use lambda operator
    public int Count => employees.Count();

    //create default constructor
    public EmployeeList() { }

    //create a method that adds employee sent to the list. No return value
    public void AddEmp(Employee emp)
    {
        employees.Add(emp);//add employee to the list
    } 

    //create employee from data sent. No return value
    public void AddEmp(string inName, int inID, decimal inHourlyWage)
    {
        //declare a variable
        Employee emp = new Employee(inName, inID, inHourlyWage);
        //call the other AddEmp
        AddEmp(emp);
    }

    //create a method that deletes employee from the list. No return value
    public void DeleteEmp(Employee emp) => employees.Remove(emp);

    //insert employee at the index
    public void InsertEmp(Employee emp, int index) => employees.Insert(index, emp);

    //create an indexer
    public Employee this[int i]
    { //q12 - indexer property with exception
        get
        {
            if (i < 0 || i >= Count)
                throw new ArgumentOutOfRangeException(i.ToString());
            return employees[i];
        }
        set { employees[i] = value; }
    }

}

class Employee
{
    //use auto-implemented property
    public int ID { get; set; }
    public string Name { get; set; }
    public decimal HourlyWage { get; set; }
    public decimal TotalPay { get; set; }

    //create static integer that starts at 1
    private static int NextID = 1;

    //create a default constructor with default values
    public Employee()
    {
        ID = NextID++;
        Name = "John Doe";
        HourlyWage = 15.25m;
        TotalPay = 0.0m;
    }

    //create the custom constructor sending in 3 parameters
    public Employee(string inName, int inID, decimal inHourlyWage)
    {
        Name = inName;//set name, no validation is required

        //validate ID is between 1 and 250. if not, set to nextID available
        if (inID <= 1 && inID >= 250)
            NextID = inID;

        //validate hourly wage is between 12.50 and 20. If not, set to 15.25
        if (inHourlyWage <= 12.50m && inHourlyWage >= 20.0m)
            inHourlyWage = 15.25m;

        TotalPay = 0;//set total pay to 0
    }

    public string DisplayData() => ID + "\t" + Name + "\t" + HourlyWage.ToString("c") + "\t" + TotalPay.ToString("c");
}

公共部分类表单1:表单
{
公共表格1（）
{
初始化组件（）；
}
//创建班级级员工列表
EmployeeList水管工=新EmployeeList（）；
私有void Form1\u加载（对象发送方、事件参数e）
{
//运行for循环，从默认构造函数创建4个水管工。
对于（int i=0；i

员工名单类别代码

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    //create class-level employee list 
    EmployeeList plumbers = new EmployeeList();

    private void Form1_Load(object sender, EventArgs e)
    {
        //run a for loop to create 4 plumbers from the default constructor.
        for (int i = 0; i < plumbers.Count; i++)
            plumbers[i] = new Employee();

        //After they are created (within the FOR loop), change their names, 
        //plumbers[0].Name = "Nicole Fernandez";

        //add them to the employee list  

        //display in listbox
        foreach (Employee item in plumbers.Employees)
        { 
            lstDisplay.Items.Add(item.DisplayData());
        }
    }

class EmployeeList
{
    //use private access modifier to create a list of employee
    private List<Employee> employees = new List<Employee>();

    public List<Employee> Employees
    {
        get { return employees; }
        set { employees = value; }
    }

    //return the count of the employee list, use lambda operator
    public int Count => employees.Count();

    //create default constructor
    public EmployeeList() { }

    //create a method that adds employee sent to the list. No return value
    public void AddEmp(Employee emp)
    {
        employees.Add(emp);//add employee to the list
    } 

    //create employee from data sent. No return value
    public void AddEmp(string inName, int inID, decimal inHourlyWage)
    {
        //declare a variable
        Employee emp = new Employee(inName, inID, inHourlyWage);
        //call the other AddEmp
        AddEmp(emp);
    }

    //create a method that deletes employee from the list. No return value
    public void DeleteEmp(Employee emp) => employees.Remove(emp);

    //insert employee at the index
    public void InsertEmp(Employee emp, int index) => employees.Insert(index, emp);

    //create an indexer
    public Employee this[int i]
    { //q12 - indexer property with exception
        get
        {
            if (i < 0 || i >= Count)
                throw new ArgumentOutOfRangeException(i.ToString());
            return employees[i];
        }
        set { employees[i] = value; }
    }

}

class Employee
{
    //use auto-implemented property
    public int ID { get; set; }
    public string Name { get; set; }
    public decimal HourlyWage { get; set; }
    public decimal TotalPay { get; set; }

    //create static integer that starts at 1
    private static int NextID = 1;

    //create a default constructor with default values
    public Employee()
    {
        ID = NextID++;
        Name = "John Doe";
        HourlyWage = 15.25m;
        TotalPay = 0.0m;
    }

    //create the custom constructor sending in 3 parameters
    public Employee(string inName, int inID, decimal inHourlyWage)
    {
        Name = inName;//set name, no validation is required

        //validate ID is between 1 and 250. if not, set to nextID available
        if (inID <= 1 && inID >= 250)
            NextID = inID;

        //validate hourly wage is between 12.50 and 20. If not, set to 15.25
        if (inHourlyWage <= 12.50m && inHourlyWage >= 20.0m)
            inHourlyWage = 15.25m;

        TotalPay = 0;//set total pay to 0
    }

    public string DisplayData() => ID + "\t" + Name + "\t" + HourlyWage.ToString("c") + "\t" + TotalPay.ToString("c");
}

class员工列表
{
//使用私有访问修饰符创建员工列表
私有列表员工=新列表（）；
公开名单雇员
{
获取{返回员工；}
设置{employees=value；}
}
//返回员工列表的计数，使用lambda运算符
public int Count=>employees.Count（）；
//创建默认构造函数
公共雇员列表（）{}
//创建将发送的员工添加到列表的方法。无返回值
公共无效增编（员工emp）
{
employees.Add（emp）；//将员工添加到列表中
} 
//根据发送的数据创建员工。无返回值
public void addamp（名称中的字符串、inID中的整数、inHourlyWage中的小数）
{
//声明一个变量
员工emp=新员工（inName、inID、inHourlyWage）；
//调用另一个加法器
加法器（emp）；
}
//创建从列表中删除员工的方法。无返回值
public void DeleteEmp（emp）=>employees.Remove（emp）；
//在索引处插入雇员
public void InsertEmp（Employee emp，int index）=>employees.Insert（index，emp）；
//创建索引器
公共雇员本[int i]
{//q12-索引器属性，有异常
得到
{
如果（i<0 | | i>=计数）
抛出新ArgumentOutOfRangeException（i.ToString（））；
返回员工[i]；
}
设置{employees[i]=value；}
}
}

员工类别代码

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    //create class-level employee list 
    EmployeeList plumbers = new EmployeeList();

    private void Form1_Load(object sender, EventArgs e)
    {
        //run a for loop to create 4 plumbers from the default constructor.
        for (int i = 0; i < plumbers.Count; i++)
            plumbers[i] = new Employee();

        //After they are created (within the FOR loop), change their names, 
        //plumbers[0].Name = "Nicole Fernandez";

        //add them to the employee list  

        //display in listbox
        foreach (Employee item in plumbers.Employees)
        { 
            lstDisplay.Items.Add(item.DisplayData());
        }
    }

class EmployeeList
{
    //use private access modifier to create a list of employee
    private List<Employee> employees = new List<Employee>();

    public List<Employee> Employees
    {
        get { return employees; }
        set { employees = value; }
    }

    //return the count of the employee list, use lambda operator
    public int Count => employees.Count();

    //create default constructor
    public EmployeeList() { }

    //create a method that adds employee sent to the list. No return value
    public void AddEmp(Employee emp)
    {
        employees.Add(emp);//add employee to the list
    } 

    //create employee from data sent. No return value
    public void AddEmp(string inName, int inID, decimal inHourlyWage)
    {
        //declare a variable
        Employee emp = new Employee(inName, inID, inHourlyWage);
        //call the other AddEmp
        AddEmp(emp);
    }

    //create a method that deletes employee from the list. No return value
    public void DeleteEmp(Employee emp) => employees.Remove(emp);

    //insert employee at the index
    public void InsertEmp(Employee emp, int index) => employees.Insert(index, emp);

    //create an indexer
    public Employee this[int i]
    { //q12 - indexer property with exception
        get
        {
            if (i < 0 || i >= Count)
                throw new ArgumentOutOfRangeException(i.ToString());
            return employees[i];
        }
        set { employees[i] = value; }
    }

}

class Employee
{
    //use auto-implemented property
    public int ID { get; set; }
    public string Name { get; set; }
    public decimal HourlyWage { get; set; }
    public decimal TotalPay { get; set; }

    //create static integer that starts at 1
    private static int NextID = 1;

    //create a default constructor with default values
    public Employee()
    {
        ID = NextID++;
        Name = "John Doe";
        HourlyWage = 15.25m;
        TotalPay = 0.0m;
    }

    //create the custom constructor sending in 3 parameters
    public Employee(string inName, int inID, decimal inHourlyWage)
    {
        Name = inName;//set name, no validation is required

        //validate ID is between 1 and 250. if not, set to nextID available
        if (inID <= 1 && inID >= 250)
            NextID = inID;

        //validate hourly wage is between 12.50 and 20. If not, set to 15.25
        if (inHourlyWage <= 12.50m && inHourlyWage >= 20.0m)
            inHourlyWage = 15.25m;

        TotalPay = 0;//set total pay to 0
    }

    public string DisplayData() => ID + "\t" + Name + "\t" + HourlyWage.ToString("c") + "\t" + TotalPay.ToString("c");
}

class员工
{
//使用自动实现的属性
公共int ID{get；set；}
公共字符串名称{get；set；}
公共十进制小时数{get；set；}
公共十进制TotalPay{get；set；}
//创建从1开始的静态整数
私有静态int NextID=1；
//使用默认值创建默认构造函数
公职人员（）
{
ID=NextID++；
Name=“约翰·多伊”；
小时里程=15.25m；
总工资=0.0m；
}
//创建自定义构造函数并发送3个参数
public Employee（名称中的字符串、整数、小数）
{
Name=inName；//设置名称，不需要验证
//验证ID介于1和250之间。如果不是，则设置为nextID available
如果（inID=250）
NextID=inID；
//验证小时工资是否介于12.50和20之间。如果不是，则设置为15.25
如果（室内尺寸=20.0m）
室内尺寸=15.25m；
TotalPay=0；//将TotalPay设置为0
}
公共字符串DisplayData（）=>ID+“\t”+Name+“\t”+HourlyWage.ToString（“c”）+“\t”+TotalPay.ToString（“c”）；
}

首先，如果要使用循环创建一个包含4名管道工的列表，则需要循环迭代4次。这通常是通过将初始计数器值设置为0，然后在小于所需数量时循环来完成的：

for (int i = 0; i < 4; i++)

由于似乎没有任何公共方法来更新现有的水管工，我们可以直接访问

员工

列表来重命名水管工。有两种方法可以做到这一点。一种是使用循环，并在名称中使用循环计数器的一部分：

// After they are created (within the FOR loop), change their names 
for(int i = 0; i < plumbers.Employees.Count; i++)
{
    plumbers.Employees[i].Name = string.Format("Plumber #{0}", i); 
}

或者，如果你真的想成为一个花花公子，你可以生成一个名字列表（我从中提取了这些名字），然后为每个水管工从列表中随机抽取一个名字并分配它（然后从列表中删除它，这样水管工都有唯一的名字）：

//在创建它们之后（在FOR循环中），更改它们的名称
//生成一个名称列表
var namepardidates=新列表
{
“奥利维亚”、“阿米莉亚”、“夏洛特”、“艾娃”、“艾拉”、“阿拉贝拉”、“极光”，
“阿德琳”，“佩内洛普”，“埃莉诺”，“以斯拉”，“亚舍”，“阿提库斯”，
“德克兰”、“奥利弗”、“塞拉斯”、“米洛”、“利维”、“亨利”、“怀亚特”
};
//循环遍历每个水管工，并随机选择一个名称
var rnd=新随机数（）；
foreach（管道工中的var管道工。员工）
{
//选择一个随机名称，分配该名称，然后将其从候选名称中删除
var nameIndex=rnd.Next（nameCandidates.Count）；
plumber.Name=姓名候选人[姓名索引]；
namePendidates.RemoveAt（nameIndex）；
}

for到达第一个

时，列表是空的。计数为零，因此
for
将不会执行。下一个语句尝试访问一个不存在的元素，因为列表也是空的。@MarkLarter那么我如何执行它，正如问题所说，我必须运行一个for循环，创建4个水管工，并在t之后更改他们的名称hat..参见答案。您只需要使要添加项的循环运行固定次数，而不是使用限制作为开始时为零的计数