Question

I’m trying to configure a data source for a dropdown list.
The database table have fields’ (id, value, parenttypeid)
The parent typeid can be 0 or 1,2..etc,
I want to populate the dropdown list according to parent and child
can be shown like -:>

Parent1
    Child1
    Child2
Parent 2

I tried this by ordering the result but could not get the format.
If anyone got idea please reply
Thanks

Answer 1

    class Node
    {
        public string Name { get; set; }
        public List<Node> Child { get; private set; }

        public Node(string name)
        {
            Child = new List<Node>();
            Name = name;
        }
    }

    static void Main(string[] args)
    {
        var listItems = new List<string>();
        var root = new Node("Root");
        root.Child.Add(new Node("1"));
        root.Child.Add(new Node("3"));
        var node = new Node("4");
        var nd = new Node("5");
        nd.Child.Add(new Node("7"));
        node.Child.Add(nd);
        node.Child.Add(new Node("6"));
        root.Child.Add(node);

        GetNames(root, listItems);

        foreach (var listItem in listItems)
        {
            Console.WriteLine(listItem);
        }
    }

    static void GetNames(Node parent, List<string> result)
    {
        result.Add(parent.Name);
        foreach (var child in parent.Child)
        {
            GetNames(child, result);
        }
    }