TreeView C#

Here is some code for you to check, there are some side effects which I am sure you will be able to fix easily, i would do it but hey it's your project.

Hopefully you will get the idea, just find the point where you call your sub form.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace tree
{
    public partial class Form1 : Form
    {
        TreeNode parent = null;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            tv.CheckBoxes = true;
            parent = tv.Nodes.Add("Root");
            parent.Nodes.Add("Apples");
            parent.Nodes.Add("Pears");
            parent.Nodes.Add("Plums");
            //parent.Text = "Child :" + (n.Checked ? "True" : "False");  


        }

        private void cb_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (!findNode(cb.SelectedItem.ToString()))
            {
                parent.Nodes.Add(cb.Text);
                    if(!cb.Items.Contains(cb.Text))
                        cb.Items.Add(cb.Text);
            }
        }

        private bool findNode(string what)
        {
            bool found = false;
            for (int i = 0; i < tv.Nodes.Count; i++)
            {
                TreeNode n = tv.Nodes[i];
                for (int j = 0; j < n.Nodes.Count; j++)
                {
                    string s = n.Nodes[j].Text;
                    if (s.IndexOf(":") > 0)
                        s = s.Substring(0, s.IndexOf(":"));

                    if (s == what)
                    {
                    //you know what you want to check for checked items!!!  you will need to play around here
 
                        if (n.Nodes[j].Checked && (parent = n.Nodes[j]).Checked)
                        {
                            found = true;
                            break;
                        }
                    }
                }
            }
            return(found);
        }

        private void cb_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                te.Focus();  
                /*
                if (!findNode(cb.Text))
                {
                    parent.Nodes.Add(cb.Text);
                    cb.Items.Add(cb.Text);
                }
                 */

            }
        }

        private void te_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                string s = cb.Text;
                if(s.IndexOf(":") > 0)
                    s = cb.Text.Substring(0, cb.Text.IndexOf(":"));

                if (!findNode(s))
                {
                    parent.Nodes.Add(s + ":" + te.Text);
                    if(!cb.Items.Contains(cb.Text))
                        cb.Items.Add(cb.Text);
                }
                else
                {
                 parent.Text = s + ":" + te.Text;

                }
            }
        }
    }
}

I don't understand the need for the combobox. I assume there is a reason but I don't understand it.
 
Is it possible for an item in the combobox to be in multiple categories in the treeview? I think that question is very fundamental to the design of your data and is therefore highly relevant to how the data is shown. If the answer is that no, an item must be in just one category, then what I would do is to automatically synchronize the two controls, the combobox and the treeview. I can understand that you don't want to bother with that, but you might be able to make everything easier by binding the data source to the form, and then the requirement could probably be solved easier.

Ok, so then you can use NodeMouseClick event to assign a global TreeNode object  in both cases, this is only needed to simplify code writing.

at the point where you determine if the node exists you can test  for a value but I think you need to look for a value separator like a ":" to get the sub string and test for a value,
if there is no separator you then know that you need to add the value of txtQty otherwise test to see if the value is greater or lesser than txtQty

selectedNod.Text += ":" + txtQty.Text;

If a node does not exist after you enter a new value in the combobox, at this point you should know who the parent is because you have checked the tree nodes for a match and you can do

 selectedNode = parentNode.Nodes.Add("Combobox.Text");  //parent node would also be a temp global object, but make sure that these are null before you loop through the tree nodes.

at this point selectedNode is the node that relates to the new item in the combo box.

if you already have a qty you can add it in the Add.(...) or

selectedNod.Text += ":" + txtQty.Text;

then do you otherstuff

remember I am working blind here so I hope this is not confusing.

whatever you do to the selectedNode object will affect the actual tree node.

You got it.  So if I select Apple in the combobox, Apple in treeview must be selected.

Ok,  If you select from combo box you try and match with a node is this correct?

I understand your question and No, you can do it in any order, however to make it work, like I said the comboxbox text has to match the child node text example Fruit (parent node) >>> Apple (child node). Apple must be selected from the combobox otherwise nothing will happen.

Do you need to click on a tree node (I know this seems a silly question) before you can select from the combo box?

If so, you can set a global TreeNode to the node selected and use this for your validation and other processes

eg if you click on Apple

in the NodeMouseClick event  you can say TreeNode node = e.Node

at this point you have access to the node parent, the node and be able to add to the node like

TreeNode newNode = node.Add(combox. Text + ":" + qty.Text);

Do you understand what I mean?

The subform is just to create a new product or in other words a product that doesn't exist in the combobox. I can say the category,and then list three prices and stores. When I click okay it adds it to the combobox and the treeview underneath the correct category.

I have had a quick look at your code, what is the purpose of the sub form.

Adding the qty value to the node text and extracting it is is simple enough but I am not sure what you are doing with the sub form.

Just the value, thanks alot.

I sort of understand what you are after but just confirm for me, do you want a text box to show next to the item or just the qty value

root--|
         Fruit
            |
            |
            Apples ( 1 )  or a text box?