Question

我想从我的代码中删除嵌套的do-while循环。我使用这些嵌套的do-while来重新输入值，如果它无效，我正在验证Employee类中的值。我是c＃的新手，所以请帮我减少这段代码。

FirstName，LastName是属性。

我将嵌套的do-while复制到方法中，并将employeeDetails.FirstName和employeeDetails.LastName作为方法的参数发送，但它不起作用，因为FirstName和LastName是该类的属性。

这是我的入门级。

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace Employee_Details
{
    class EntryClass
    {
        static void Main(string[] args)
        {
            string strChoice;
            List<Employee> employeeList = new List<Employee>();
            do
            {
                Employee employeeDetails = new Employee();

                bool exception=false;
                do
                {
                    Console.WriteLine("Enter first name");
                    try
                    {
                        employeeDetails.FirstName = Console.ReadLine();
                        exception = false;
                    }
                    catch (Exception e)
                    {
                        Console.WriteLine(e.Message);
                        exception = true;
                    }
                } while (exception);

                exception = false;
                do
                {
                    Console.WriteLine("enter last name");
                    try
                    {
                        employeeDetails.LastName = Console.ReadLine();
                        exception = false;
                    }
                    catch (Exception e)
                    {
                        Console.WriteLine(e.Message);
                        exception = true;
                    }
                } while (exception);

                exception = false;
                do
                {
                    Console.WriteLine("enter date of birth in dd/MM/yyyy ");
                    try
                    {
                        employeeDetails.SetDOB(Console.ReadLine());
                        exception = false;
                    }
                    catch(Exception e)
                    {
                        Console.WriteLine(e.Message);
                        exception = true;
                    }
                } while (exception);
                employeeList.Add(employeeDetails);
                Console.WriteLine("Do You want to continue?");
                strChoice = Console.ReadLine().ToLower();
            } while (strChoice == "yes");

            var query = from employeeDetails in employeeList
                        select new
                        {
                            firstName = employeeDetails.FirstName,
                            lastName = employeeDetails.LastName,
                            dob = employeeDetails.DateOfBirth.ToString("d/M/yyyy", System.Globalization.CultureInfo.InstalledUICulture),
                            age=employeeDetails.GetAge()
                      };
            foreach (var employee in query)
            {
                Console.WriteLine($"{employee.firstName},{employee.lastName},{employee.dob},{employee.age}");
            }
        }
    }
}

我的入门课程看起来像这样。

    using System;
    using System.Collections.Generic;
    using System.Globalization;
    using System.Linq;
    using System.Text;
    using System.Text.RegularExpressions;
    using System.Threading.Tasks;

    namespace Employee_Details
    {
        class Employee
        {
            private string first_name;
            private string last_name;
            private DateTime date_of_birth;

            public DateTime DateOfBirth => date_of_birth;

            public void SetDOB(string dob)
            {
                if (!DateTime.TryParseExact(dob, "d/M/yyyy", CultureInfo.InvariantCulture, DateTimeStyles.None, out DateTime returnDate))
                {
                    throw new Exception("Invalid Date");
                }
                else if (GetAge() <= 0)
                {
                    throw new Exception("Birth Year shoud not be greater then current year");
                }
                date_of_birth= returnDate;
            }

            public string LastName
            {
                set
                {
                    last_name = CheckString(value);
                }
                get
                {
                    return last_name;
                }
            }

            public string FirstName
            {
                set
                {
                    first_name = CheckString(value);
                }
                get
                {
                    return first_name;
                }
            }

            private string CheckString(string value)
            {
                string returnString = "";
                var regex = new Regex(@"(?i)^[a-z.,\s]+$");
                bool res = regex.IsMatch(value);
                if (res)
                {
                    returnString = value;
                }
                else
                {
                    throw new Exception("Invalid String");
                }
                return returnString;
            }

            public int GetAge()
            {
                DateTime now = DateTime.Today;
                int age = now.Year - date_of_birth.Year;
                return age;
            }
        }
    }

当我们提供任何无效数据时，FirstName，LastName和DateOfBirth将抛出异常。

Answer 1

使用DateTime.TryParse代替捕获例外。你可以改进一些事情，比如说。为什么在从不抛出异常的属性上使用异常循环，比如从控制台读取FirstName和LastName？

使其更具可读性的一种方法是定义Func代理：

Func<bool> askContinue = () =>
{
    Console.WriteLine("Do You want to continue?");
    return Console.ReadLine().Trim().Equals("yes", StringComparison.InvariantCultureIgnoreCase);
};
Func<string> askFirstName = () =>
{
    Console.WriteLine("Enter first name");
    return Console.ReadLine().Trim();
};
Func<string> askLastName = () =>
{
    Console.WriteLine("Enter last name");
    return Console.ReadLine().Trim();
};
Func<DateTime?> askDateOfBirth = () =>
{
    Console.WriteLine("Enter date of birth(dd/MM/yyyy)");
    string dobStr = Console.ReadLine().Trim();
    DateTime dob;
    if (DateTime.TryParse(dobStr, out dob))
        return dob;
    return null;
};

现在循环本身被简化为必要且可读：

List<Employee> employeeList = new List<Employee>();
bool addEmployee = true;

while (addEmployee)
{
    var emp = new Employee
    {
        FirstName = askFirstName(),
        LastName = askLastName()
    };
    DateTime? dob = askDateOfBirth();
    while (!dob.HasValue)
        dob = askDateOfBirth();
    emp.DateOfBirth = dob.Value;

    employeeList.Add(emp);
    addEmployee = askContinue();
}

Answer 2

您可以创建一个返回名称的方法：

private static string GetName(string question)
{
    string name = null;
    do
    {
        Console.WriteLine(question);
        try
        {
            name = Console.ReadLine();
        }
        catch (Exception e)
        {
            name = null;
            Console.WriteLine(e.Message);
        }
    } while (string.IsNullOrEmpty(name));

    return name;
}

然后在你的程序中你可以设置你的行为：

do {
    var employeeDetails = new Employee
    {
        FirstName = GetName("Enter firstname and press enter."),
        LastName = GetName("Enter firstname and press enter."),
    };

    employeeList.Add(employeeDetails);
    Console.WriteLine("Do You want to continue?");
    strChoice = Console.ReadLine().ToLower();
} while (strChoice == "yes");

现在添加DOBgetter，你去了，你已经成功地减少了嵌套。

想在内循环时删除do

2 个答案: