由于其保护级别而无法访问

Question

I can't figure this out. The problem is that the distance, club, cleanclub, hole, scores and par all say inaccessible due to protection level and I don't know why because I thought I did everything right.

namespace homeworkchap8
{
    public class Clubs
    {
        protected string club;
        protected string distance;
        protected string cleanclub;
        protected string scores;
        protected string par;
        protected string hole;            

        public string myclub
        {
            get { return club; }
            set {club = value; }
        }        
        public string mydistance
        {
            get { return distance; }
            set { distance = value; }
        }        
        public string mycleanclub
        {
            get { return cleanclub; }
            set { cleanclub = value; }
        }       
        public string myscore
        {
            get { return scores; }
            set { scores = value; }
        }       
        public string parhole
        {
            get { return par; }
            set { par = value; }
        }       
        public string myhole
        {
            get { return hole; }
            set { hole = value;}
        }
    }   
}

this is the derived class:

namespace homeworkchap8
{
    public class SteelClubs : Clubs, ISwingClub
    {
        public void SwingClub()
        {
            Console.WriteLine("You hit a " + myclub + " " + mydistance);
        }

        public void clean()
        {
            if (mycleanclub != "yes")
            {
                Console.WriteLine("your club is dirty");
            }
            else
            {
                Console.WriteLine("your club is clean");
            }
        }

        public void score()
        {   
            Console.WriteLine("you are on hole " + myhole + " and you scored a " + 
                myscore + " on a par " + parhole);
        }            
    }
}

This is the interface:

namespace homeworkchap8
{
    public interface ISwingClub
    {
        void SwingClub();
        void clean();
        void score();
    }  
}

here is the main code:

namespace homeworkchap8
{
    class main
    {    
        static void Main(string[] args)
        {    
            SteelClubs myClub = new SteelClubs();
            Console.WriteLine("How far to the hole?");
            myClub.distance = Console.ReadLine();
            Console.WriteLine("what club are you going to hit?");
            myClub.club = Console.ReadLine();
            myClub.SwingClub();

            SteelClubs mycleanclub = new SteelClubs();
            Console.WriteLine("\nDid you clean your club after?");
            mycleanclub.cleanclub = Console.ReadLine();
            mycleanclub.clean();

            SteelClubs myScoreonHole = new SteelClubs();
            Console.WriteLine("\nWhat hole are you on?");
            myScoreonHole.hole = Console.ReadLine();
            Console.WriteLine("What did you score on the hole?");
            myScoreonHole.scores = Console.ReadLine();
            Console.WriteLine("What is the par of the hole?");
            myScoreonHole.par = Console.ReadLine();

            myScoreonHole.score();

            Console.ReadKey();    
        }
    }
}

Answer 1

In your base class Clubs the following are declared protected

• club;
• distance;
• cleanclub;
• scores;
• par;
• hole;

which means these can only be accessed by the class itself or any class which derives from Clubs .

In your main code, you try to access these outside of the class itself. eg:

Console.WriteLine("How far to the hole?");
myClub.distance = Console.ReadLine();

You have (somewhat correctly) provided public accessors to these variables. eg:

public string mydistance
{
    get
    {
        return distance;
    }
    set
    {
        distance = value;
    }
}        

which means your main code could be changed to

Console.WriteLine("How far to the hole?");
myClub.mydistance = Console.ReadLine();

Answer 2

Dan, it's just you're accessing the protected field instead of properties.

See for example this line in your Main(...) :

myClub.distance = Console.ReadLine();

myClub.distance is the protected field, while you wanted to set the property mydistance .

I'm just giving you some hint, I'm not going to correct your code, since this is homework; ;)

Answer 3

myClub.distance = Console.ReadLine();

should be

myClub.mydistance = Console.ReadLine(); 

use your public properties that you have defined for others as well instead of the protected field members.

Answer 4

In your Main method, you're trying to access, for instance, club (which is protected), when you should be accessing myclub which is the public property that you created.

Answer 5

You organized class interface such that public members begin with "my". Therefore you must use only those members. Instead of

myScoreonHole.hole = Console.ReadLine();

you should write

myScoreonHole.myhole = Console.ReadLine();

Answer 6

It's because you cannot access protected member data through its class instance. You should correct your code as follows:

namespace homeworkchap8
{
    class main
    {    
        static void Main(string[] args)
        {    
            SteelClubs myClub = new SteelClubs();
            Console.WriteLine("How far to the hole?");
            myClub.mydistance = Console.ReadLine();
            Console.WriteLine("what club are you going to hit?");
            myClub.myclub = Console.ReadLine();
            myClub.SwingClub();

            SteelClubs mycleanclub = new SteelClubs();
            Console.WriteLine("\nDid you clean your club after?");
            mycleanclub.mycleanclub = Console.ReadLine();
            mycleanclub.clean();

            SteelClubs myScoreonHole = new SteelClubs();
            Console.WriteLine("\nWhat hole are you on?");
            myScoreonHole.myhole = Console.ReadLine();
            Console.WriteLine("What did you score on the hole?");
            myScoreonHole.myscore = Console.ReadLine();
            Console.WriteLine("What is the par of the hole?");
            myScoreonHole.parhole = Console.ReadLine();

            myScoreonHole.score();

            Console.ReadKey();    
        }
    }
}

Answer 7

You need to use the public properties from Main , and not try to directly change the internal variables.

Answer 8

The reason being you cannot access protected member data through the instance of the class.

Reason why it is not allowed is explained in this blog .

Answer 9

Though it is irrelevant to the case at hand, for the benefit of the next person who arrives at this article through a search engine, if the of your base class is marked as , derived classes will incur a diagnostic.

Instead, you must promote the private method to .

The protected method remains inaccessible to consumers of the derived class unless said class overrides it with a constructor.