如何将简单（枚举）参数传递给C＃中的类？

Question

class Person //I'm want to pass the parameter "Gender"
{
    public string firstName;
    public string lastName;
    public int age;
    //public string gender;

This is a piece of code that I'm working with. I'm new to programming, and I'm working with C#. I have an enumeration called "Gender" it consists of "Male" and "Female". I have a class called "Person" and I want to pass a parameter telling the system that each new "Person" MUST have a gender, male or female. I'm pretty sure I'm supposed to pass the parameter near the top close to the class.

Answer 1

I want to pass a parameter telling the system that each new Person MUST have a gender

You enforce that through the constructor:

public class Person //I'm want to pass the parameter "Gender"
{
    public string firstName;
    public string lastName;
    public int age;
    public Gender gender;  // recommend storing the enum instead of a string

    public Person (Gender gender)
    {
        this.gender = gender;
    }
}

Implementing a constructor with a parameter removes the "default" constructor, so anyone that creates a Person must supply a gender.

I's also recommend using properties instead of fields but that's a separate issue...

Answer 2

First, you can easily just add a new member for the person's Gender with a type of Gender (which is, I assume, the name of the enum):

public Gender Gender;

Since you want to force that a person must have a specific gender upon the object's creation you need to stipulate that in the class's constructor :

public Person(Gender PersonGender)
{
   Gender = PersonGender;
}

So your class becomes something like this:

class Person
{
    public string firstName;
    public string lastName;
    public int age;
    public Gender Gender;

    public Person(Gender PersonGender)
    {
       Gender = PersonGender;
    }
}

Note that in C#, unlike in C/C++, it doesn't really matter where you put the methods and the members. Just keep them organized for ease of reading.

Answer 3

class Person
{
    public string firstName;
    public string lastName;
    public int age;
    public Gender Gender;
}

See MSDN for more information on enum types in C#.