C# How to show structured list in a TreeView

Question

2.00/5 (1 vote)

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Hey guys,

I have a problem which I cant solve yet. I just need a hint, how to solve it.

Problem:
I get the following list from a sql query:

GROUP:
01. Employees/Administration
01. Employees/Managment
01. Employees/Sales
...
02. Type/Member
02. Type/Customer

...
and so on...

How can I get this into a treeview? To loook like this:

- All
-- 01. Employees<b></b>
--- Administration

One of my tries:

C#

if (rs.RecordCount &gt; 0)
            {
                while (!rs.EOF)
                {
                    tempNode = tree;
                    string[] array = rs.Fields[&quot;GRUPPE&quot;].Value.ToString().Split(&#39;/&#39;);

                    foreach (string str in array)
                    {
                        if (tempNode.Nodes.ContainsKey(str))
                        {
                            tempNode = tree.Nodes[str];
                        }
                        else
                        {
                            TreeNode newNode = new TreeNode();
                            newNode.Name = str;
                            newNode.Text = str;

                            //*** PROBLEM!!!
                            tree.Nodes.Add(newNode);
                            //***
                            tempNode = newNode;
                        }
                    }

                    rs.MoveNext();
                }

Basically, my problem is how to can I add a Node on the 2nd or 3rd or Nrd level? Dynamically?

Hope you understand my problem?!

Kind Regards

Example of how it should be:

http://img198.imageshack.us/img198/5951/9zq.png[^

Posted 28-Jun-13 20:26pm

kaengraeng

Updated 30-Jun-13 17:20pm

v2

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Comments

Mahesh Bailwal 29-Jun-13 3:59am

Below is the syntax to add child node.
TreeNode nodeParent = new TreeNode();
TreeNode nodeChild = new TreeNode();
nodeParent.Nodes.Add(nodeChild);
treeView1.Nodes.Add(nodeParent);

kaengraeng 29-Jun-13 4:32am

thanks for your answer. unfortunately it doesnt help. When I have a string like this:
Employees/Administration/Teamleader

I want it to look like this in the treeview
Employees = 1st level
Administration = 2nd level
Teamleader = 3nd level

So how should i loop this string to add the children?

BillWoodruff 30-Jun-13 17:28pm

The obvious mistake in your code ... assuming 'tree is the TreeView, and 'tempNode is a TreeNode ... is: tempNode = tree;

Second, you need to show more detail in your question on exactly how you wish the final output to appear.

kaengraeng 30-Jun-13 23:21pm

thanks for the answer and please see the link above in my first page. Thats how it should be.

2 solutions

Solution 1

I created sample for this. Hope it will help

data.txt

Employees/Administration/Teamleader
Employees/Administration/Manager
Employees/Sales/Manager
Employees/Sales/Executive

string []str = File.ReadAllLines(@"D:\data.txt");
          TreeNode root = new TreeNode();
          root.Text = "All";

          foreach (string s in str)
          {
              string[] arr = s.Split('/');
              TreeNode department = null;
              if (!root.Nodes.ContainsKey(arr[1]))
              {

                  root.Nodes.Add(arr[1], arr[1]);
              }

            department =  root.Nodes[arr[1]];
            department.Nodes.Add(new TreeNode(arr[2]));
          }

          treeView1.Nodes.Add(root);

Posted 28-Jun-13 23:36pm

Mahesh Bailwal

Updated 28-Jun-13 23:37pm

v2

Comments

kaengraeng 30-Jun-13 23:24pm

thanks for your help, but your code is very static, which means if I would have a string like this: 'Employees/Administration/Teamleader/MisterA' the last part 'MisterA' will not be listed!

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kaengraeng · Accepted Answer · 2013-06-30T17:42:00

Ok i figured it out now. Please see below my code sample, which works fine for me so far.

string[] str = File.ReadAllLines(@"C:\test\test.txt");
            TreeNode root = new TreeNode();
            root.Text = "All";

            foreach (string s in str)
            {
                string[] arr = s.Split('/');
                TreeNode parent = root;

                foreach (string ss in arr)
                {
                    if (!parent.Nodes.ContainsKey(ss))
                    {
                        TreeNode newNode = new TreeNode();
                        newNode.Name = ss;
                        newNode.Text = ss;
                        parent.Nodes.Add(newNode);
                        parent = newNode;
                    }
                    else
                    {
                        parent = parent.Nodes[ss];
                    }
                }
            }
            treeView1.Nodes.Add(root);
            treeView1.ExpandAll();