Create a tree recursivly

I want to create a Treeview in C# which will group file by prefix (here the prefix is a marked by the separator _). The following files should give this tree:
Files list:

p_a
p_a_test
p_LIG
p_p
p_p_c
p_p_c2
p_p_ccc
p_p_test
p_tres
TestLineGraph1
TestLineGrpah


Corresponding tree:

|--p_
|--p_a
|--p_a_test
|--p_LIG
|--p_p
|--p_p_
|--p_p_c
|--p_p_c2
|--p_p_ccc
|--p_p_test
|--p_tres
TestLineGraph1
TestLineGraph


And how I do it:

` private GraphUINode(List subNodes, GraphUINode parent, string name, int lvl = 0)
: base(parent.m_viewDataSubControl)
{
parent.Nodes.Add(this);
this.Name = name;
this.Text = name;

string currentPrefix = "";
int pertinentSubNodes = 0;
while (pertinentSubNodes children = new List();
foreach (string child in subNodes)
{
// The child is in the same group than the previous one
if (child.StartsWith(currentPrefix))
{
children.Add(child);
}
else
{
// Create a node only if needed
if (children.Count > 1)
{
// Create the new node
new GraphUINode(children, this, currentPrefix, lvl + 1);
children.Clear();
children.Add(child);
}
else
{
if (children.Count == 1)
{
new GraphTemplateNode(this, m_viewDataSubControl, children[0]);
children.Clear();
}
new GraphTemplateNode(this, m_viewDataSubControl, child);
}
currentPrefix = "";
for (int i = 0; i

but this looks very dirty. How can I improve it?

Is this a bug ?

The correspondending tree you showed is not consistent. It should look like

|--p_
    |--p_a
    |--p_a_
          |--p_a_test  <- this
    |--p_LIG
    |--p_p
    |--p_p_
        |--p_p_c
        |--p_p_c2
        |--p_p_ccc
        |--p_p_test
    |--p_tres
TestLineGraph1
TestLineGraph

Style

-
You should always be consistent with the coding style you use. So if you omit (

-
You shouldn't shorten variable / parameter names because that removes readability. -> lvl

Comments

Comments should describe why something is done. What is done should be described by the code itself by using meaningful names for classes, methods, parameters.

A comment which describes what is done like

// Create the new node
new GraphUINode(children, this, currentPrefix, lvl + 1);

should be removed.

Refactoring

Can't be done until the possibility of the bug as mentioned is cleared.

As the root problem to solve is to create a tree structure based on a List I would extract this tree creation outside of the constructor to a separate method which only takes a List as input parameter and is returning something like

class TreeNode
{
    public String Name { get; private set; }
    public IList ChildNodes { get; private set; }
    public TreeNode()
    {
        ChildNodes = new List();
    }
    public void FillChildNodes(IList childNodes)
    {

    }
}

StackExchange Code Review Q#73837, answer score: 4