C# Treeview checking if node exists

Question

I\'m trying to populate a treeview from an XmlDocument. The Root of the tree is set as \'Scripts\' and from the root the next level should be \'Departments\' which is within the

Answer 1

if(treeView1.Nodes.ContainsKey("DEPARTMENT")){
//...
}

EDIT: Recursive method:

 bool exists = false;
        foreach (TreeNode node in treeView1.Nodes) {
            if (NodeExists(node, "DEPARTMENT"))
                exists = true;
        }
    private bool NodeExists(TreeNode node, string key) {
        foreach (TreeNode subNode in node.Nodes) {
            if (subNode.Text == key) {
                return true;
            }
            if (node.Nodes.Count > 0) {
                NodeExists(node, key);
            }
        }
        return false;
    }

Answer 2

You can do something like this:

TreeNode parentNode = t1.Parent;
if (parentNode != null}
{
    if(parentNode.Nodes.Cast<TreeNode>().ToList().Find(t => t.Text.Equals(node["DEPARTMENT"].InnerXml) == null)
    {
        //Add node
    }
}
else
{
    bool isFound = true;
    if (treeView1.Nodes.Cast<TreeNode>().ToList().Find(t => t.Text.Equals(node["DEPARTMENT"].InnerXml) == null)
    {
        isFound = false;
    }

    if(!isFound)
    {
        //Add node
    }
}

Answer 3

I use,

string department = node["DEPARTMENT"].InnerXml;
TreeNode node = parentNode.Nodes[department] ?? parentNode.Nodes.Add(department, department);

That line guarantees that a lookup of the value department will be done first, if not found it creates it. You have to do the double entry in Add() so it will have a key value you can do the lookup with the .Nodes[department].

Answer 4

Not sure about the document structure...
Couldn't you use Linq to Xml, load the document and get the distinct row ( row = department?) and consider only those elements to create a TreeNode? It is more efficient than trying to find if a node with such a text has already been added. ex:

 var rows =      (  from row  in XDocument.Load(document).Root.Elements("row")
                    select row
                 ).Distinct(new SampleElementComparerOnNameAttribute());

Here the EqualityComparer is made on the "name" attribute value assuming the doc structure to be

<rows><row name='dep1'><script>script1</script><script>script2</script></row><row name='dep1'><script>script3</script><script>script4</script></row></rows>

Answer 5

http://www.vbdotnetforums.com/listviews-treeviews/13278-treeview-search.html#post39625

http://forums.asp.net/t/1645725.aspx/1?Check+if+child+Node+exists+on+treeview

Answer 6

If your XML document has a set structure where 'Departments' will always be indexed at 1;

ie:

index:[0] Scripts
    index:[1] Department
        index:[2] Script
    index:[1] Department2
        index:[2] Script

Then you could encapsulate the following code into a method where 'name' is a string parameter and the return type is boolean.

foreach (TreeNode node in uxTreeView.Nodes[0].Nodes) {
    if (node.Name.ToLower() == name.ToLower()) {
        return true;
    }
}
return false;

The idea is you would call that function each time you encounter a 'Department' node in your Xml, before creating the TreeNode.

Full example:

private bool DepartmentNodeExists(string name) {
    foreach (TreeNode node in uxTreeView.Nodes[0].Nodes) {
        if (node.Name.ToLower() == name.ToLower()) {
            return true;
        }
    }
    return false;
}

Lastly, the easy way:

private bool DepartmentNodeExists(string name) {
    if (uxTreeView.Nodes[0].ContainsKey(name)) {
        return true;
    }
    else {
        return false;
    }
}

These are all just refactored and encapsulated into their own named methods, you of course could just call:

if (uxTreeView.Nodes[0].ContainsKey(name)) {
    // do not create TreeNode
}

...during your parsing of your XML. PS. These examples all assume that you have the first root node in the TreeView already created and added to the TreeView.