C# 局部变量不断获取错误消息、新的datetime时间戳，并且所有代码都不会显示在cmd.exe中

我对这段代码有3个问题，我想寻求一些帮助

我似乎每次在person2中都会收到一条错误消息，称为myAge和DateOfBirth的局部变量已经在这个范围中定义了？这怎么可能

我的第二个问题是，我似乎无法从球员的出生日期中删除时间戳。。我只需要日期，不需要时间戳

我的第三个也是最后一个问题是，所有代码不会同时显示在cmd.exe中？我必须按enter键才能显示下一个玩家，但我想同时显示所有玩家

有人能帮忙吗？提前谢谢你

    public enum Gendertype { Male, Female };
    public class Person
    {
    public string FirstName { get; set; }
    public string MiddleName { get; set; }
    public string LastName { get; set; }
    public DateTime DateOfBirth { get; set; }
    public string Nationality { get; set; }
    public Gendertype Gender { get; set; }

    public Person(string fn, string mn, string ln, DateTime dob, string n, Gendertype g)
    {
        FirstName = fn;
        MiddleName = mn;
        LastName = ln;
        DateOfBirth = dob;
        Nationality = n;
        Gender = g;
    }

}
class Program
{ 
static void Main()
{
    Person person1 = new Person("Rafael" + "\n", "" + "\n", "Nadal" + "\n", new DateTime(1986,06, 03), "Spanish" + "\n", Gendertype.Male);
    Console.WriteLine("Player 1: \n First name = {0} Middle name = {1 } Last name = {2} Date of birth = {3} \n Nationality = {4} Gender = {5}", person1.FirstName, person1.MiddleName, person1.LastName, person1.DateOfBirth, person1.Nationality, person1.Gender);
        DateTime DateOfBirth = DateTime.Parse("1986/06/03");
        TimeSpan myAge = DateTime.Now.Subtract(DateOfBirth);
        Console.WriteLine(" Age:");
        Console.WriteLine(myAge.TotalDays/365);
        Console.ReadLine();

            Person person2 = new Person("Rafael" + "\n", "" + "\n", "Nadal" + "\n", new DateTime(1988, 07, 04), "Spanish" + "\n", Gendertype.Male);
            Console.WriteLine("Player 2: \n First name = {0} Middle name = {1 } Last name = {2} Date of birth = {3} \n Nationality = {4} Gender = {5}", person2.FirstName, person2.MiddleName, person2.LastName, person2.DateOfBirth, person2.Nationality, person2.Gender);
            DateTime dob = DateTime.Parse("1988/07/04");
            TimeSpan Age = DateTime.Now.Subtract(DateOfBirth);
            Console.WriteLine(" Age:");
            Console.WriteLine(myAge.TotalDays / 365);
            Console.ReadLine();


            person2.FirstName = "Molly";
            Console.WriteLine("Player 2: \n First name = {0} Middle name = {1 } Last name = {2} Date of birth = {3} \n Nationality = {4} Gender = {5}", person1.FirstName, person1.MiddleName, person1.LastName, person1.DateOfBirth, person1.Nationality, person1.Gender);
            Console.WriteLine("person1 Name = {0} Age = {1}", person2.FirstName, person2.DateOfBirth);


            Console.WriteLine("Press any key to exit.");
            Console.ReadKey();
        }
  }

}

在声明person1之后，您已经在Main（）函数中声明了myAge/DateOfBirth变量：

DateTime-DateOfBirth=DateTime.Parse（“1986/06/03”）

TimeSpan myAge=DateTime.Now.Subtract（出生日期）

我假设在声明person2之后，您正试图声明另一对同名变量，但您仍然在同一个Main（）函数中。编译器正在抱怨您在声明变量时已经声明了变量。要解决这个问题，只需去掉第二行的

DateTime

和

TimeSpan

部分。这样，您就不会试图用相同的名称声明新变量，而是使用旧的变量

您正在使用

DateTime.Now

计算年龄，其中包括小时、秒和毫秒。如果只想获取日期，请尝试DateTime.Today（）。对于文本友好的输出，您应该查看DateTime格式以获得正确的输出（）

在每组输出之后都有一个Console.ReadLine（）调用。这将停止代码的常规执行，以等待用户输入。只要去掉这些行，它就会立即执行

试试这个

public enum Gendertype { Male, Female };
    public class Person
    {
    public string FirstName { get; set; }
    public string MiddleName { get; set; }
    public string LastName { get; set; }
    public DateTime DateOfBirth { get; set; }
    public string Nationality { get; set; }
    public Gendertype Gender { get; set; }
    public int Age 
    {
        return DateTime.Now.Subtract(DateOfBirth).TotalDays / 365;
    }
    public Person(string fn, string mn, string ln, DateTime dob, string n, Gendertype g)
    {
        FirstName = fn;
        MiddleName = mn;
        LastName = ln;
        DateOfBirth = dob;
        Nationality = n;
        Gender = g;
    }

}
class Program
{ 
    static void Main()
    {
        Person person1 = new Person("Rafael" + "\n", "" + "\n", "Nadal" + "\n", new DateTime(1986,06, 03), "Spanish" + "\n", Gendertype.Male);
        Console.WriteLine("Player 1: \n First name = {0} Middle name = {1 } Last name = {2} Date of birth = {3} \n Nationality = {4} Gender = {5}", person1.FirstName, person1.MiddleName, person1.LastName, person1.DateOfBirth, person1.Nationality, person1.Gender);

        Console.WriteLine(" Age:");
        Console.WriteLine(person1.Age);
        //Console.ReadLine(); this waits for your enter key

        Person person2 = new Person("Rafael" + "\n", "" + "\n", "Nadal" + "\n", new DateTime(1988, 07, 04), "Spanish" + "\n", Gendertype.Male);
        Console.WriteLine("Player 2: \n First name = {0} Middle name = {1 } Last name = {2} Date of birth = {3} \n Nationality = {4} Gender = {5}", person2.FirstName, person2.MiddleName, person2.LastName, person2.DateOfBirth, person2.Nationality, person2.Gender);

        Console.WriteLine(" Age:");
        Console.WriteLine(person2.Age);
        //Console.ReadLine(); this waits for your enter key


        person2.FirstName = "Molly";
        Console.WriteLine("Player 2: \n First name = {0} Middle name = {1 } Last name = {2} Date of birth = {3} \n Nationality = {4} Gender = {5}", person1.FirstName, person1.MiddleName, person1.LastName, person1.DateOfBirth, person1.Nationality, person1.Gender);
        Console.WriteLine("person1 Name = {0} Age = {1}", person2.FirstName, person2.DateOfBirth.ToShortDateString());


        Console.WriteLine("Press any key to exit.");
        Console.ReadKey();
     }
}

---

1） 如果错误消息是您无法共享的秘密，我们将无法帮助您。2） DateTime类型始终由日期和时间组成-如果需要特定的输出格式（如“yyyy/MM/dd”），请在呈现输出时指定它。3） 您确实放置了那些

Console.ReadLine（）在那里，这就是控制台所做的。1）您向我们展示的代码没有显示此问题。2） 
Console.WriteLine
使用，您可以指定输出的格式如下：
出生日期={3:yyyy/MM/dd}
，3），因为您将
Console.ReadLine（）放在在每一个之后，使其暂停，直到您点击回车键；阅读“如果标准输入设备是键盘，ReadLine方法会一直阻塞，直到用户按下Enter键。”请注意，您的年龄计算也不正确。请参见和。