Iterating through a List to show in TreeView

Question

I have four lists that I am trying to get the contents to show up in a TreeView on my Form .
My current problem is that only the last item in each list is showing up in the view.
I am sure it has something to do with how I am iterating through the list but I am pretty stuck on how to get each individual list item to show up in the tree.

My tree structure is:

Dog
   Husky
      huskylist
   Chiwawa
      chiwawlist
Cat
   Siamese
       siameselist
   Tabby
        tabbylist

My code for the Form where the tree view is:

public partial class Form1 : Form
{
    private Model m_modelObj;
    public Form1(Model modelObj)
    {
        InitializeComponent();

        m_modelObj = modelObj;

        List<Tabby> tabbyList = m_modelObj.TabbyList;
        List<Siamese> siameseList = m_modelObj.SiameseList;
        List<Husky> huskyList = m_modelObj.HuskyList;
        List<Chiwawa> chiwawaList = m_modelObj.ChiwawaList;

       //tree code

        //add husky list
        TreeNode node8 = null;
        foreach (var item in huskyList)
        {
            node8 = new TreeNode(item.name);       
        }

        TreeNode[] husky = new TreeNode[] { node8 };

        //add chiwawa list
        TreeNode node9 = null;
        foreach (var item in chiwawaList)
        {
            node9 = new TreeNode(item.name);
        }

        TreeNode[] chiwawa = new TreeNode[] { node9 };

        //dog breed
        TreeNode node2 = new TreeNode("Husky", husky);
        TreeNode node3 = new TreeNode("Chiwawa", chiwawa);
        TreeNode[] dog = new TreeNode[] { node2, node3 };

        //dog parent
        TreeNode treeNode = new TreeNode("Dogs", dog);
        treeView1.Nodes.Add(treeNode);

        //add tabby list
        TreeNode nodes = null;

        foreach (var item in tabbyList)
        {
            nodes = new TreeNode(item.name);
        }

        TreeNode[] tabby = new TreeNode[] { nodes };

        //add siamese list
        TreeNode node7 = null;
        foreach (var item in siameseList)
        {
            node7 = new TreeNode(item.name);
        }

        TreeNode[] siamese = new TreeNode[] { node7 };

        //cat breed
        TreeNode node4 = new TreeNode("Siamese", siamese);
        TreeNode node5 = new TreeNode("Tabby", tabby);
        TreeNode[] cat = new TreeNode[] { node4, node5 };

        //cat parent
        treeNode = new TreeNode("Cats", cat);
        treeView1.Nodes.Add(treeNode);
    }

    private void Form1_Load(object sender, EventArgs e)
    {

    }

    private void addDetailsBtn_Click(object sender, EventArgs e)
    {
        string animalType = comboBoxAnimalType.SelectedItem.ToString();
        this.Hide();
        PetInfoForm aPetInfoForm = new PetInfoForm(animalType, m_modelObj);
        aPetInfoForm.Closed += (s, args) => this.Close();
        aPetInfoForm.Show();
    }
}

Answer 1

Create Object and Dynamic array in c# Refer here

TreeView Basic to understand Refer here

when you are creating the sub nodes you are overwrite the instance. you should maintain the nodes in a array.

        //tree code

        //add husky list
        List<TreeNode> node8 = new List<TreeNode>();
        foreach (var item in huskyList)
        {
            node8.Add(new TreeNode(item.name));
        }

        TreeNode[] husky = node8.ToArray();

        //add chiwawa list
        List<TreeNode> node9 = new List<TreeNode>();
        foreach (var item in chiwawaList)
        {
            node9.Add(new TreeNode(item.name));
        }

        TreeNode[] chiwawa = node9.ToArray();

        //dog breed
        TreeNode node2 = new TreeNode("Husky", husky);
        TreeNode node3 = new TreeNode("Chiwawa", chiwawa);
        TreeNode[] dog = new TreeNode[] { node2, node3 };

        //dog parent
        TreeNode treeNode = new TreeNode("Dogs", dog);
        treeView1.Nodes.Add(treeNode);

        //add tabby list
        List<TreeNode> nodes = new List<TreeNode>();

        foreach (var item in tabbyList)
        {
            nodes.Add(new TreeNode(item.name));
        }

        TreeNode[] tabby =nodes.ToArray();

        //add siamese list
        List<TreeNode> node7 = new List<TreeNode>();
        foreach (var item in siameseList)
        {
            node7.Add(new TreeNode(item.name));
        }

        TreeNode[] siamese = node7.ToArray();

        //cat breed
        TreeNode node4 = new TreeNode("Siamese", siamese);
        TreeNode node5 = new TreeNode("Tabby", tabby);
        TreeNode[] cat = new TreeNode[] { node4, node5 };

        //cat parent
        treeNode = new TreeNode("Cats", cat);
        treeView1.Nodes.Add(treeNode);

Or Using LINQ you can create the tree like this

        // Code Using Linq
        TreeNode husky = new TreeNode("Husky", huskyList.Select(x => new TreeNode(x.name)).ToArray());
        TreeNode chiwawa = new TreeNode("Chiwawa", chiwawaList.Select(x => new TreeNode(x.name)).ToArray());
        TreeNode Siamese = new TreeNode("Siamese", siameseList.Select(x => new TreeNode(x.name)).ToArray());
        TreeNode Tabby = new TreeNode("Tabby", tabbyList.Select(x => new TreeNode(x.name)).ToArray());
        //parent nodes
        treeView1.Nodes.AddRange(new[] {
            new TreeNode("Dog", new TreeNode[] { husky, chiwawa }),
            new TreeNode("Cat", new TreeNode[] { Siamese, Tabby })
            });