如何創建可以建立父子關系的課程

Question

我在這里看到了很多有關我的問題的文章，但沒有一篇能真正回答我的問題。 我正在創建我的Branch對象的類，您可以像TreeView控件的TreeNode對象一樣進行設想。 每個分支機構可以在其下方（因此在其上方）具有任意數量的分支子級。 這是我相當簡單的課程：

public class Branch {
    public string Name { get; set; }
    public string Link { get; set; }
    public Branch Parent { get; private set; }
    public List<Branch> Children { get; set; }

    internal Branch(string Name, string Link) {
        this.Name = Name;
        this.Link = Link;
        this.Children = new List<Branch>();
    } // Branch - Constructor - Overload

    internal Branch(string Name, string Link, List<Branch> Children) {
        this.Name = Name;
        this.Link = Link;
        this.Children = Children;

        this.Children.ForEach(delegate(Branch branch) {
            branch.Parent = this;
        });
    } // Branch - Constructor - Overload

    public bool HasChildren {
        get { return this.Children.Count > 0; }
    } // HasChildren - Property - ReadOnly

    public string Path {
        get {
            string Result = "";

            Branch parent = this;
            while (parent != null) {
                Result = string.Format("{0}/{1}", parent.Name, Result);
                parent = parent.Parent;
            } // while stepping up the tree

            return string.IsNullOrWhiteSpace(Result) ? "" : Result.Substring(0, Result.Length - 1);
        } // get
    } // Path - Property - ReadOnly

如果我在實例化時添加子代，則如下所示：

List<Branch> Branches = new List<Branch>() {
    new Branch("First", "#"),
    new Branch("Second", "#"),
    new Branch("Third", "#", new List<Branch>() {
        new Branch("ThirdSub1", "#"),
        new Branch("ThirdSub2", "#")
    }),
    new Branch("Fourth", "#"),
    new Branch("Fifth", "#"),
    new Branch("Sixth", "#", new List<Branch>() {
        new Branch("SixthSub1", "#"),
        new Branch("SixthSub2", "#", new List<Branch>() {
            new Branch("SixthSub2Sub1", "#"),
            new Branch("SixthSub2Sub2", "#"),
            new Branch("SixthSub2Sub3", "#", new List<Branch>() {
                new Branch("Deep Deep Deep Undercover", "#"),
            }),
        }),
    }),
    new Branch("Seventh", "#"),
    new Branch("Eighth", "#"),
};

但是，如果我執行以下操作：

List<Branch> Branches = new List<Branch>();
Branch Test = Branches.Add(new Branch("Something", ""));
Test.Children.Add(new Branch("Child Here", ""));

“此處的子級”節點沒有與之關聯的父級。 因此，它已損壞，並且Path屬性當然不起作用。

我以為我可以覆蓋List的Add方法，但這是不允許的。 處理此問題的最佳方法是什么？ 目前，我並沒有創建自己喜歡的MyBranches這樣的Collection類，但是如果在實現IList或ISet或Collection時可以做某種需要的事情，那么我願意這樣做。 但請提供一個例子。

謝謝！

Answer 1

面向將來尋求相同解決方案的人們，以下是完整的課程：

public class Branch {
    public string Name { get; set; }
    public string Link { get; set; }
    public Branch Parent { get; set; }
    public TreeBranches Children { get; private set; }

    internal Branch(string Name, string Link) {
        this.Name = Name;
        this.Link = Link;
        this.Children = new TreeBranches(this);
    } // Branch - Constructor - Overload

    internal Branch(string Name, string Link, TreeBranches Children) {
        this.Name = Name;
        this.Link = Link;
        this.Children = Children;

        this.Children.ToList().ForEach(delegate(Branch branch) {
            branch.Parent = this;
        });
    } // Branch - Constructor - Overload

    /// <summary>
    /// Returns a boolean indicating if the given Branch has any child Branches.
    /// </summary>
    public bool HasChildren {
        get { return this.Children.Count > 0; }
    } // HasChildren - Property - ReadOnly

    /// <summary>
    /// Gets the path from the oldest ancestor to the current Branch.
    /// </summary>
    public string Path {
        get {
            string Result = "";

            Branch parent = this;
            while (parent != null) {
                Result = string.Format("{0}/{1}", parent.Name, Result);
                parent = parent.Parent;
            } // while stepping up the tree

            return string.IsNullOrWhiteSpace(Result) ? "" : Result.Substring(0, Result.Length - 1);
        } // get
    } // Path - Property - ReadOnly

} // Branch - Class

public class TreeBranches : IList<Branch> {
    private List<Branch> branches = new List<Branch>();
    private Branch owner;

    public TreeBranches() {
        this.owner = null;
    }

    public TreeBranches(Branch owner) {
        this.owner = owner;
    }

    public void Add(Branch branch) {
        branch.Parent = this.owner;
        this.branches.Add(branch);
    }

    #region Standard IList Method Implementation

    IEnumerator<Branch> IEnumerable<Branch>.GetEnumerator() { return this.branches.GetEnumerator(); }
    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() { return this.branches.GetEnumerator(); }
    public int IndexOf(Branch item) { return this.branches.IndexOf(item); }
    public void Insert(int index, Branch item) { this.branches.Insert(index, item); }
    public void RemoveAt(int index) { this.branches.RemoveAt(index); }
    public Branch this[int index] {
        get { return this.branches[index]; }
        set { this.branches[index] = value; }
    }

    public void Clear() { this.branches.Clear(); }
    public bool Contains(Branch item) { return this.branches.Contains(item); }
    public void CopyTo(Branch[] array, int arrayIndex) { this.branches.CopyTo(array, arrayIndex); }
    public int Count { get { return this.branches.Count(); } }
    public bool IsReadOnly { get { return this.IsReadOnly; } }
    public bool Remove(Branch item) { return this.branches.Remove(item); }

    #endregion Standard IList Method Implementation
} // TreeBranches - Class

Answer 2

您可以從Collection<T>而不是List<T>派生出來， List<T>更快，並且針對性能進行了優化，但是Collection<T>更具擴展性，可以覆蓋Add()和其他。

如果性能不成問題，則使用Collection<T> ，如果性能成問題，則不使用Reed在您自己的類中包含List<T>的示例。