详解C#中的接口属性以及属性访问器的访问限制

public interface ISampleInterface
{
  // Property declaration:
  string Name
  {
    get;
    set;
  }
}

string IEmployee.Name
{
  get { return "Employee Name"; }
  set { }
}

string IEmployee.Name
{
  get { return "Employee Name"; }
  set { }
}

string ICitizen.Name
{
  get { return "Citizen Name"; }
  set { }
}

interface IEmployee
{
  string Name
  {
    get;
    set;
  }

  int Counter
  {
    get;
  }
}

public class Employee : IEmployee
{
  public static int numberOfEmployees;

  private string name;
  public string Name // read-write instance property
  {
    get
    {
      return name;
    }
    set
    {
      name = value;
    }
  }

  private int counter;
  public int Counter // read-only instance property
  {
    get
    {
      return counter;
    }
  }

  public Employee() // constructor
  {
    counter = ++counter + numberOfEmployees;
  }
}

class TestEmployee
{
  static void Main()
  {
    System.Console.Write("Enter number of employees: ");
    Employee.numberOfEmployees = int.Parse(System.Console.ReadLine());

    Employee e1 = new Employee();
    System.Console.Write("Enter the name of the new employee: ");
    e1.Name = System.Console.ReadLine();

    System.Console.WriteLine("The employee information:");
    System.Console.WriteLine("Employee number: {0}", e1.Counter);
    System.Console.WriteLine("Employee name: {0}", e1.Name);
  }
}

210
Hazem Abolrous

Enter number of employees: 210
Enter the name of the new employee: Hazem Abolrous
The employee information:
Employee number: 211
Employee name: Hazem Abolrous

private string name = "Hello";

public string Name
{
  get
  {
    return name;
  }
  protected set
  {
    name = value;
  }
}

public class Parent
{
  public virtual int TestProperty
  {
    // Notice the accessor accessibility level.
    protected set { }

    // No access modifier is used here.
    get { return 0; }
  }
}
public class Kid : Parent
{
  public override int TestProperty
  {
    // Use the same accessibility level as in the overridden accessor.
    protected set { }

    // Cannot use access modifier here.
    get { return 0; }
  }
}

public interface ISomeInterface
{
  int TestProperty
  {
    // No access modifier allowed here
    // because this is an interface.
    get;
  }
}

public class TestClass : ISomeInterface
{
  public int TestProperty
  {
    // Cannot use access modifier here because
    // this is an interface implementation.
    get { return 10; }

    // Interface property does not have set accessor,
    // so access modifier is allowed.
    protected set { }
  }
}

public class BaseClass
{
  private string name = "Name-BaseClass";
  private string id = "ID-BaseClass";

  public string Name
  {
    get { return name; }
    set { }
  }

  public string Id
  {
    get { return id; }
    set { }
  }
}

public class DerivedClass : BaseClass
{
  private string name = "Name-DerivedClass";
  private string id = "ID-DerivedClass";

  new public string Name
  {
    get
    {
      return name;
    }

    // Using "protected" would make the set accessor not accessible. 
    set
    {
      name = value;
    }
  }

  // Using private on the following property hides it in the Main Class.
  // Any assignment to the property will use Id in BaseClass.
  new private string Id
  {
    get
    {
      return id;
    }
    set
    {
      id = value;
    }
  }
}

class MainClass
{
  static void Main()
  {
    BaseClass b1 = new BaseClass();
    DerivedClass d1 = new DerivedClass();

    b1.Name = "Mary";
    d1.Name = "John";

    b1.Id = "Mary123";
    d1.Id = "John123"; // The BaseClass.Id property is called.

    System.Console.WriteLine("Base: {0}, {1}", b1.Name, b1.Id);
    System.Console.WriteLine("Derived: {0}, {1}", d1.Name, d1.Id);

    // Keep the console window open in debug mode.
    System.Console.WriteLine("Press any key to exit.");
    System.Console.ReadKey();
  }
}

  Base: Name-BaseClass, ID-BaseClass
  Derived: John, ID-BaseClass