How can I work out this part of a class diagram?-CodePudding

For school homework I'm supposed to work out a class diagram in C#. Everything went smoothly, but I'm struggling with the constructor for the Track part.

So I think I have to convert a SectionTypes -> Section to put it in the LinkedList, but this doesn't seem logical to me, or am I missing something? Should I convert it in any way or is my overall code for Section wrong?

Here is the class diagram

Here is the part of Section:

namespace Model
{
    public enum SectionTypes { Straight, LeftCorner, RightCorner, StartGrid, Finish }
    internal class Section
    {
        public SectionTypes SectionType { get; set; }
    }
}

And finally here is where I'm trying to make the constructor, Track:

namespace Model
{
    internal class Track
    {
        public string Name { get; set; }
        public LinkedList<Section> Sections { get; set; }

        public Track(string name, SectionTypes[] sections)
        {
            Name = name;
            // set Sections here
        }
    }
}

The error that I get is CS1503, when I try to add anything to Sections in the front, which means the types aren't the same.

Thanks for reading, and thank you for helping in advance!

CodePudding user response：

Here's what I did. By the way, I renamed the SectionTypes enumeration to SectionType (that way, it reads 'SectionType.Finish, not SectionTypes.Finish`).

First I created the enum the same as you:

public enum SectionType
{
    Straight,
    LeftCorner,
    RightCorner,
    StartGrid,
    Finish,
}

and the Section class pretty much the same way:

public class Section
{
    public SectionType SectionType { get; set; }
}

I'm not sure why the class diagram is laid out the way it is, but you need to translate a SectionType to a Section in order to get it to work. That's pretty easy; a Section is a pretty stupid/simple wrapper around a single SectionType. So, things end up looking like:

public class Track
{
    public string Name { get; set; }
    public LinkedList<Section> Sections { get; set; } = new LinkedList<Section>();

    public Track(string name, SectionType[] sections)
    {
        Name = name;
        foreach (var section in sections)
        {
            Sections.AddLast(new Section { SectionType = section });
        }
    }
}

Note that I construct the Sections LinkedList. It can either be done the way I show, or it could be done in the constructor. But, the magic is to convert the incoming SectionType[] sections into a collection of Section type. I'm sure that there is a way to do this with LINQ (though I don't have a lot of experience with the LinkedList collection). But, doing it explicitly like this makes it more clear.