Access upper class property for List<T> in T class C#

Question

There are my classes:

public class myClass1
{
    public int Code { get; set; }
    public List<myItem> Items { get; set; }
}
public class myClass2
{
    public int Code { get; set; }
    public List<myItem> Items { get; set; }
}
public class myItem
{
    private void MyMethod()
    {
        int ParentClass_CodeProperty = ???
    }
}

How to access (Code property) in upper (or Parent) class ?

example :

string ParentClass_CodeProperty = this.Parent.GetType().GetProperty("Code").GetValue(a, null).ToString()

Answer 1

One thing you can do is modify your MyItem class to have a ParentClassCode property, and let this get set through the constructor:

public class MyItem
{
    public int ParentClassCode { get; set; }

    public MyItem(int parentClassCode)
    {
        ParentClassCode = parentClassCode;
    }
    private void MyMethod()
    {
        // Now we can refer to ParentClassCode
    }
}

Then you would set the parent class code on creation of a new MyItem:

MyClass1 class1 = new MyClass1();
class1.Code = 42;
class1.Items.Add(new MyItem(class1.Code));

Another way to do this, without using the constructor, would be to create a method on the containing class that should be used to add items to the list, and in that AddItem method, set the property:

public class MyClass1
{
    public int Code { get; set; }
    public List<MyItem> Items { get; set; }

    public void AddItem(MyItem item)
    {
        if (item == null) throw new ArgumentNullException();
        item.ParentClassCode = Code;
        Items.Add(item);
    }
}

Of course this means there's more work to do to prevent users from bypassing your AddItem method and calling MyClass1.Items.Add(item);, but you get the idea.