C# WPF: Create TreeView from text file - wpf

Question

I create my TreeViewItems with the class Node . In the example nodes are specified in source code. But how do I do it if the nodes are to be imported from a text file with content like this:
text file content
Any ideas?
I have tried the following.
public MainWindowVM()
{
private ObservableCollection<Node> mRootNodes;
public IEnumerable<Node> RootNodes { get { return mRootNodes; } }
List<string[]> TreeNodes = new List<string[]>();
string[] lines = null;
try
{
lines = System.IO.File.ReadAllLines(MainWindow.TextFilePath , System.Text.Encoding.Default);
}
catch (IOException ex)
{
MessageBox.Show(ex.Message);
Environment.Exit(0);
}
if (lines == null || lines.Length == 0)
{
MessageBox.Show("Text file has no content!");
Environment.Exit(0);
}
foreach (var line in lines)
{
TreeNodes.Add(line.Split('|'));
}
Node newNode = null;
Node childNode = null;
Node root = new Node() { Name = TreeNodes[0][0] };
if (TreeNodes[0].Length > 1)
{
newNode = new Node() { Name = TreeNodes[0][1] };
root.Children.Add(newNode);
}
for (int s = 2; s < TreeNodes[0].Length; s++)
{
childNode = new Node() { Name = TreeNodes[0][s] };
newNode.Children.Add(childNode);
newNode = childNode;
}
}
but I get only the first two nodes. I do not know how to build the whole TreeView with a loop.
TreeView

Answer 1

input example
Root|A
Root|B|C
Root|B|D
Root|E
the problem with your code is that you only process TreeNodes[0] element. to process a collection of elements you need a loop
public MainWindowVM()
{
private ObservableCollection<Node> mRootNodes;
public IEnumerable<Node> RootNodes { get { return mRootNodes; } }
string[] lines = null;
try
{
lines = System.IO.File.ReadAllLines(MainWindow.TextFilePath , System.Text.Encoding.Default);
}
catch (IOException ex)
{
MessageBox.Show(ex.Message);
Environment.Exit(0);
}
if (lines == null || lines.Length == 0)
{
MessageBox.Show("Text file has no content!");
Environment.Exit(0);
}
Dictionary<string, Node> nodeCache = new Dictionary<string, Node>();
// processing each line
foreach (var line in lines)
{
Node parentNode = null;
string key = null;
// in each line there are one or more node names, separated by | char
foreach (string childNodeName in line.Split('|'))
{
Node childNode;
// names are not unique, we need a composite key (full node path)
key += "|" + childNodeName;
// each node has unique key
// if key doesn't exists in cache, we need to create new child node
if (false == nodeCache.TryGetValue(key, out childNode))
{
childNode = new Node { Name = childNodeName };
nodeCache.Add(key, childNode);
if (parentNode != null)
// each node (exept root) has a parent
// we need to add a child node to parent ChildRen collection
parentNode.Children.Add(childNode);
else
// root nodes are stored in a separate collection
mRootNodes.Add(childNode);
}
// saving current node for next iteration
parentNode = childNode;
}
}
}