I have a N-Ary non sorted in any way tree and each node can have 0-N children. Given the data structure below, how can I fill the tree view assuming you have an array of TermNodes and that array is the first level of the TreeView? I have not been able to come up with a recursive way to do this.
class TermNode
{
public string Name;
public string Definition;
public List<TermNode> Children
}
Here is a bit of code to get you started with the recursion. It's not tested (I can't right now), but you should get the idea:
public static void BuildTreeView(TreeNodeCollection Parent, List<TermNode> TermNodeList)
{
foreach (TermNode n in TermNodeList)
{
TreeNode CurrentNode = Parent.Add(n.Name);
// no need to recurse on empty list
if (n.List.Count > 0) BuildTreeView(CurrentNode.Nodes, n.List);
}
}
// initial call
List<TermNode> AllTermNodes = /* all your nodes at root level */;
BuildTreeView(treeView1.Nodes, AllTermNodes);
Just took out Generics for a spin.. Worked nicely. Worth a look at...
public interface INode<T>
{
List<T> Children { get; }
}
class TermNode:INode<TermNode>
{
public string Name;
public string Definition;
public List<TermNode> Children { get; set; }
public TermNode()
{
this.Children = new List<TermNode>();
}
}
public class TreeBuilder<T> where T : INode<T>
{
public Func<T, TreeNode> obCreateNodeFunc;
public void AddNode(TreeView obTreeView, T obNodeToAdd, TreeNode obParentNodeIfAny)
{
TreeNodeCollection obNodes;
if (obParentNodeIfAny == null)
{
obNodes = obTreeView.Nodes;
}
else
{
obNodes = obParentNodeIfAny.Nodes;
}
int iNewNodeIndex = obNodes.Add(obCreateNodeFunc(obNodeToAdd));
TreeNode obNewNode = obNodes[iNewNodeIndex];
foreach (T child in obNodeToAdd.Children)
{
AddNode(obTreeView, child, obNewNode);
}
}
}
// calling code - Some class
static TreeNode GetTreeNodeFor(TermNode t)
{
return new TreeNode(t.Name); // or any logic that returns corr TreeNode for T
}
void Main()...
{
TermNode[] arrNodesList;
// populate list with nodes
TreeBuilder<TermNode> tb = new TreeBuilder<TermNode>();
tb.obCreateNodeFunc = GetTreeNodeFor;
foreach (TermNode obNode in arrNodesList)
{
tb.AddNode(treeView, obNode, null);
}
}
Thanks All I was getting confused because I did not realize that for a given TreeNode tn, tn.Nodes.Add would return the added TreeNode
Once you know that the solution is straight forward like so
private void /*TreeNode*/ RecursiveAdd(OntologyNode on, TreeNode tn)
{
if (on.Children.Count == 0)
{
return;
}
foreach (OntologyNode child in on.Children)
{
TreeNode tCur = tn.Nodes.Add(child.Name);
tCur.Tag = child;//optional for some selected node events
RecursiveAdd(child, tCur);
}
}
and to start of the recursive call
foreach( OntologyNode on in Nodes )
{
if (on.IsTopLevelNode == true)// internal not pertinent to this code snippet
{
TreeNode tn = tvOntoBrowser.Nodes.Add(on.Name);
tn.Tag = on;
if (on.Children.Count > 0)
{
RecursiveAdd(on, tn);
}
}
}
Related
why extension method does not return the modified node in Insertion operations.
But It Working Fine at the time of Linked list Creation.
Extension method should return the modified Node.
What is the perfect way to do this.
IS extension method good in performance
Code follows
public class Node
{
public Object Data { get; set; }
public Node NextNode { get; set; }
}
public static class ListOperations
{
public static void CreateLinkedList(this Node node, Object data)
{
if (node.Data == null)
{
node.Data = data;
}
else
{
Node newnode = new Node();
newnode.Data = data;
Node current = new Node();
current = node;
while (current.NextNode != null)
{
current = current.NextNode;
}
current.NextNode = newnode;
node = current;
}
}
public static void InsertNode(this Node node1, Object data, int position)
{
Node newnode = new Node();
newnode.Data = data;
if (position == 1)
{
newnode.NextNode = node1;
node1 = newnode;
}
}
}
class Program
{
static void Main(string[] args)
{
Node node = new Node();
//random Singly LinkedList
node.CreateLinkedList(10);
node.CreateLinkedList(11);
node.CreateLinkedList(12);
node.CreateLinkedList(13);
node.CreateLinkedList(14);
node.CreateLinkedList(15);
node.InsertNode(20, 1);// this method does not return node value what is inserted.
}
}
There are many things wrong with your code, and we can deal with them later. But let's answer your questions first. I will be a bit literal and direct, since I can't assume why you have done it the way it is done.
why extension method does not return the modified node in Insertion operations.
Since your method doesn't return anything
But It Working Fine at the time of Linked list Creation.
Yes, since that code doesn't ever modify the this Node node parameter
Extension method should return the modified Node.
Only if you actually return any data from the method!
What is the perfect way to do this.
See below
IS extension method good in performance
Extension method compared with what? Compared with member method written similarly, there should really be no performance difference in the cases relevant to your example
Perfect way to do it:
So first things first: There is no need to write an extension method here. Why wouldn't you write a regular member method? Extensions are usually done when the class you want to add the functionality is not directly available for you to edit, typically as the code belongs to a third party
Second, you don't quite seem to understand the references and how the pass-by-value works. First let me post a better code, and then explain it
public class Node {
public object Data { get; set; }
public Node NextNode { get; set; }
public Node(object data) {
Data = data;
}
public Node AppendNode(object data) {
var newNode = new Node(data);
var current = this;
while (current.NextNode != null)
current = current.NextNode;
current.NextNode = newNode;
return newNode;
}
public Node SetFirstNode(object data) {
return new Node(data) { NextNode = this };
}
}
class Program {
static void Main(string[] args) {
var linkedList = new Node(10);
linkedList.AppendNode(11);
linkedList.AppendNode(12);
linkedList.AppendNode(13);
linkedList.AppendNode(14);
linkedList.AppendNode(15);
linkedList = linkedList.SetFirstNode(20);
}
}
The important things to notice from the perspective of your main question (why the insert did not work) is that the method SetFirstNode actually returns the newly created node and in Main, we re-assign the linkedlist as such linkedList = linkedList.SetFirstNode(20);
Now, you can actually write a static method and pass by ref the linkedlist, but that is not a good practice, in my opinion. Nevertheless, the code would look like below
public static class ListOperations {
public static void InsertNode(ref Node linkedList, object data) {
linkedList = new Node(data) { NextNode = linkedList };
}
}
Among other things to notice, I am calling the node object as linkedList, CreateLinkedList as AppendNode and InsertNode as SetFirstNode on purpose, so you can understand the code better.
Below is the same code with generic argument instead of object Data and using a proper InsertNode method
public class Node<T> {
public T Data { get; set; }
public Node<T> Next { get; set; }
public override string ToString() {
return Data.ToString();
}
public Node(T data) {
Data = data;
}
public Node<T> AppendNode(T data) {
var newNode = new Node<T>(data);
var current = this;
while (current.Next != null)
current = current.Next;
current.Next = newNode;
return newNode;
}
/// <summary>
/// Inserts a new node into the linkedlist as the desired position
/// </summary>
/// <param name="position">0-based index for the final position of new node</param>
/// <param name="newNode">The newly created node containing data</param>
/// <returns>returns the first node of the linkedlist</returns>
public Node<T> InsertNode(T data, int position, out Node<T> newNode) {
var current = this;
position--;
newNode = new Node<T>(data);
if (position < 0) {
newNode.Next = current;
return newNode;
}
for (int i = 0; i < position; ++i)
current = current.Next;
newNode.Next = current.Next;
current.Next = newNode;
return this;
}
}
class Program {
static void Main(string[] args) {
var linkedList = new Node<int>(10);
linkedList.AppendNode(11);
linkedList.AppendNode(12);
linkedList.AppendNode(13);
linkedList.AppendNode(14);
linkedList.AppendNode(15);
linkedList = linkedList.InsertNode(20, 0, out var newNode);
}
}
I'm trying to import an XML file of nodes into the same node structure in a TreeView using C#. I have found a lot of example that use a single node structure, but have had a lot of issues traversing the XML file and populating the TreeView with it. This is a sample of the XML file:
<?xml version="1.0"?>
<xmlRoot>
<ProductGroup>
<Group>
<GroupName>Soda</GroupName>
<Classifications>
<Classification>
<ClassificationName>Regular</ClassificationName>
<Containers>
<Container>
<ContainerType>Can</ContainerType>
<ContainerName>SmallCan</ContainerName>
</Container>
<Container>
<ContainerType>bottle</ContainerType>
<ContainerName>SmallBottle</ContainerName>
</Container>
</Containers>
</Classification>
<Classification>
<ClassificationName>Diet</ClassificationName>
<Containers>
<Container>
<ContainerType>Can</ContainerType>
<ContainerName>SmallCan</ContainerName>
</Container>
</Containers>
</Classification>
</Classifications>
</Group>
<Group>
<GroupName>Water</GroupName>
<Classifications>
<Classification>
<ClassificationName>Regular</ClassificationName>
<Containers>
<Container>
<ContainerType>Bottle</ContainerType>
<ContainerName>EcoBottle</ContainerName>
</Container>
</Containers>
</Classification>
</Classifications>
</Group>
</ProductGroup>
</xmlRoot>
I've tried using something like this:
treProducts.Nodes.Clear();
XDocument xdoc = XDocument.Load("ProductDocument.xml");
foreach (XElement groupElement in xdoc.Descendants("Group"))
{
treProducts.Nodes.Add(groupElement.Element("GroupName").Value);
treProducts.SelectedNode = treProducts.Nodes[groupElement.Element("GroupName").Value];
foreach (XElement ClassificationElement in groupElement.Descendants("Classification"))
{
treProducts.SelectedNode.Nodes.Add(groupElement.Element("ClassificationName").Value);
treProducts.SelectedNode = treProducts.Nodes[groupElement.Element("ClassificationName").Value];
foreach (XElement ContainerElement in groupElement.Descendants("Container"))
{
treProducts.SelectedNode.Nodes.Add(ContainerElement.Element("ContainerName").Value);
}
}
}
I'm trying to get the tree to show:
Soda
Regular
SmallCan
SmallBottle
Diet
SmallCan
Water
Regular
EcoBottle
...but the tree is only showing Soda and it seems to skip the rest, except if I comment out the nested foreach statements, it will show Soda and Water.
There's something wrong with the syntax I'm using and I'm wondering if someone who understands Linq better can help see where the code is wrong.
You are using the wrong variable in your loop over the Classification Elements. Replace groupElement with ClassificationElement inside the loop.
Change:
foreach (XElement ClassificationElement in groupElement.Descendants("Classification"))
{
// groupElement.Element("ClassificationName") is null:
treProducts.SelectedNode.Nodes.Add(groupElement.Element("ClassificationName").Value);
...
}
to
foreach (XElement ClassificationElement in groupElement.Descendants("Classification"))
{
treProducts.SelectedNode.Nodes.Add(ClassificationElement.Element("ClassificationName").Value);
...
}
I suggest recursion
void AddNodes(XElement parentElement, TreeNode parent = null)
{
Queue<XElement> queue = new Queue<XElement>(parentElement.Elements());
while (queue.Count > 0)
{
TreeNode child = parent;
XElement element = queue.Dequeue();
if (!element.HasElements)
{
string value = element.Value;
element = (XElement)element.NextNode;
if (null != element && !element.HasElements)
value = element.Value;
if (null == parent)
treeView1.Nodes.Add(child = new TreeNode(value));
else
parent.Nodes.Add(child = new TreeNode(value));
child.Expand();
element = queue.Dequeue();
}
AddNodes(element, child);
}
}
AddNodes(XElement.Load("ProductDocument.xml"));
Note: dbc's answer is probably better if your XML structure is likely to change, but if you are given it as it currently stands, and it won't change - then this will slurp it right into the tree quickly, without a lot of overhead.
The reason this is complicated is that your tree node hierarchy does not correspond 1-1 to your XML hierarchy. In situations like this, I suggest introducing intermediate classes to provide a view into the base XML model data. In WPF these classes would be the View Model, but the windows forms TreeView doesn't support data binding. Despite this, the abstraction of a view model is useful here.
First, some basic view model interfaces and classes to tie together TreeNode and XElement hierarchies:
public interface ITreeNodeViewModel
{
string Name { get; }
string Text { get; }
object Tag { get; }
object Model { get; }
IEnumerable<ITreeNodeViewModel> Children { get; }
}
public abstract class TreeNodeViewModel<T> : ITreeNodeViewModel
{
readonly T model;
public TreeNodeViewModel(T model)
{
this.model = model;
}
public T Model { get { return model; } }
#region ITreeNodeProxy Members
public abstract string Name { get; }
public abstract string Text { get; }
public virtual object Tag { get { return this; } }
public abstract IEnumerable<ITreeNodeViewModel> Children { get; }
#endregion
#region ITreeNodeViewModel Members
object ITreeNodeViewModel.Model
{
get { return Model; }
}
#endregion
}
public abstract class XElementTreeNodeViewModel : TreeNodeViewModel<XElement>
{
public XElementTreeNodeViewModel(XElement node) : base(node) {
if (node == null)
throw new ArgumentNullException();
}
public XNamespace Namespace { get { return Model.Name.Namespace; } }
public override string Name
{
get { return Model.Name.ToString(); }
}
}
Next, a couple extension classes:
public static class TreeViewExtensions
{
public static void PopulateNodes(this TreeView treeView, IEnumerable<ITreeNodeViewModel> viewNodes)
{
treeView.BeginUpdate();
try
{
treeView.Nodes.PopulateNodes(viewNodes);
}
finally
{
treeView.EndUpdate();
}
}
public static void PopulateNodes(this TreeNodeCollection nodes, IEnumerable<ITreeNodeViewModel> viewNodes)
{
nodes.Clear();
if (viewNodes == null)
return;
foreach (var viewNode in viewNodes)
{
var name = viewNode.Name;
var text = viewNode.Text;
if (string.IsNullOrEmpty(text))
text = name;
var node = new TreeNode { Name = name, Text = text, Tag = viewNode.Tag };
nodes.Add(node);
PopulateNodes(node.Nodes, viewNode.Children);
node.Expand();
}
}
}
public static class XObjectExtensions
{
public static string TextValue(this XContainer node)
{
if (node == null)
return null;
//return string.Concat(node.Nodes().OfType<XText>().Select(tx => tx.Value)); c# 4.0
return node.Nodes().OfType<XText>().Select(tx => tx.Value).Aggregate(new StringBuilder(), (sb, s) => sb.Append(s)).ToString();
}
public static IEnumerable<XElement> Elements(this IEnumerable<XElement> elements, XName name)
{
return elements.SelectMany(el => el.Elements(name));
}
}
Next, view models for the three levels of your tree:
class ContainerViewModel : XElementTreeNodeViewModel
{
public ContainerViewModel(XElement node) : base(node) { }
public override string Text
{
get
{
return Model.Element(Namespace + "ContainerName").TextValue();
}
}
public override IEnumerable<ITreeNodeViewModel> Children
{
get { return Enumerable.Empty<ITreeNodeViewModel>(); }
}
}
class ClassificationViewModel : XElementTreeNodeViewModel
{
public ClassificationViewModel(XElement node) : base(node) { }
public override string Text
{
get
{
return Model.Element(Namespace + "ClassificationName").TextValue();
}
}
public override IEnumerable<ITreeNodeViewModel> Children
{
get
{
return Model.Elements(Namespace + "Containers").Elements<XElement>(Namespace + "Container").Select(xn => (ITreeNodeViewModel)new ContainerViewModel(xn));
}
}
}
class GroupViewModel : XElementTreeNodeViewModel
{
public GroupViewModel(XElement node) : base(node) { }
public override string Text
{
get
{
return Model.Element(Namespace + "GroupName").TextValue();
}
}
public override IEnumerable<ITreeNodeViewModel> Children
{
get
{
return Model.Elements(Namespace + "Classifications").Elements<XElement>(Namespace + "Classification").Select(xn => (ITreeNodeViewModel)new ClassificationViewModel(xn));
}
}
}
Now, building your tree becomes quite simple:
var xdoc = XDocument.Load("ProductDocument.xml");
var ns = xdoc.Root.Name.Namespace;
treeView1.PopulateNodes(xdoc.Root.Elements(ns + "ProductGroup").Elements(ns + "Group").Select(xn => (ITreeNodeViewModel)new GroupViewModel(xn)));
And the result:
Later, if you wish to add editing functionality to your tree, you can add the appropriate methods to ITreeNodeViewModel -- for instance, a setter method for Text. Since the ITreeNodeViewModel has saved itself in the TreeNode.Tag the appropriate methods will be available.
I am using third party library where if I wanted to created nested structure for directories I have to create like this
new ClassA("folder1", new ClassA("folder2", new ClassA("folder3")));
this will create folder structure like this folder1->folder2->folder3.
To make it simple for my users I am creating methods where users pass the path as parameter and my method process the path and should create the above object structure which internally creates folder structure.
right now I am able to parse the path like a tree but could not able to create above object structure.
This is the sample console application code
class Program
{
static void Main(string[] args)
{
List<string> Paths = new List<string>();
Paths.Add("D1");
Paths.Add("E1");
Paths.Add(#"E1\E11");
Paths.Add(#"D1\D11");
Paths.Add(#"D1\D12");
Paths.Add(#"D1\D2");
Paths.Add(#"D1\D2\D21");
Node nodeObj = new Node();
foreach (var path in Paths)
{
nodeObj.AddPath(path);
}
//var nodes = nodeObj.Nodes;
Node current = nodeObj;
int level = 0;
ReadNodes(current, level);
}
private static void ReadNodes(Node current, int level)
{
foreach (string key in current.Nodes.Keys)
{
var tablevel = level;
string tab = string.Empty;
while (tablevel>0)
{
tab = tab + " ";
tablevel--;
}
Console.WriteLine(tab +":" + key);
// The child node.
Node child;
if (current.Nodes.TryGetValue(key, out child) && child.Nodes.Count>0)
{
ReadNodes(child, level+1);
}
else { }
}
}
}
public class Node
{
private readonly IDictionary<string, Node> _nodes =
new Dictionary<string, Node>();
public IDictionary<string, Node> Nodes
{
get { return _nodes; }
}
private string Path { get; set; }
public string Source { get; set; }
public void AddPath(string path)
{
char[] charSeparators = new char[] { '\\' };
// Parse into a sequence of parts.
string[] parts = path.Split(charSeparators,
StringSplitOptions.RemoveEmptyEntries);
// The current node. Start with this.
Node current = this;
// Iterate through the parts.
foreach (string part in parts)
{
// The child node.
Node child;
// Does the part exist in the current node? If
// not, then add.
if (!current._nodes.TryGetValue(part, out child))
{
// Add the child.
child = new Node
{
Path = part
};
// Add to the dictionary.
current._nodes[part] = child;
}
// Set the current to the child.
current = child;
}
}
}
class Test : yourClass
{
string name;
Test childTest;
public Test(string name)
{
this.name = name;
this.childTest = null;
}
public Test(string name, Test test)
{
this.name = name;
this.childTest = test;
}
}
Test a = new Test("a", new Test("b", new Test("c")));
Are you just searching for a structure like this? You need two constructors one that accepts only a string and one that accepts a string and another class of the same type
I have the following class which recurs on itself to form a tree-like data structure:
public class chartObject
{
public string name { get; set; }
public int descendants { get; set; }
public List<chartObject> children { get; set; }
}
For each object in the tree I would like to populate the descendant property with the amount objects that exist underneath it.
Example structure:
chartObject1 (descendants: 4)
└-chartObject2 (descendants: 0)
└-chartObject3 (descendants: 2)
└--chartObject4 (descendants: 1)
└---chartObject5 (descendants: 0)
What would be the most efficient way of doing this?
How about the recursive formula:
children.Count + children.Sum(c => c.descendants)
This is suitable for eager-evaluation / caching if the tree is immutable (which it isn't from the class declaration). If you want efficiency even in the face of mutability, you'll find this a lot more difficult; you can consider marking parts of the tree "dirty" as it is mutated / eagerly force the re-evalutation of this metric to "bubble up" as part of a tree is mutated.
This works for me:
public void SetDescendants(chartObject current)
{
foreach (var child in current.children)
{
SetDescendants(child);
}
current.descendants = current.children.Sum(x => 1 + x.descendants);
}
I tested with this code:
var co = new chartObject()
{
name = "chartObject1",
children = new List<chartObject>()
{
new chartObject()
{
name = "chartObject2",
children = new List<chartObject>() { }
},
new chartObject()
{
name = "chartObject3",
children = new List<chartObject>()
{
new chartObject()
{
name = "chartObject4",
children = new List<chartObject>()
{
new chartObject()
{
name = "chartObject5",
children = new List<chartObject>() { }
}
}
}
}
}
}
};
And got this as the result:
For calculations to be most efficient, cache their result in the node itself. Otherwise, you'll be re-calculating the count every time the descendants property is looked up.
The cost of doing that is the need to invalidate the cache all the way up the parent chain, like this:
public class chartObject
{
private chartObject _parent;
private int? _descCache = null;
public string name { get; set; }
public int descendants {
get {
return _descCache ?? calcDescendents();
}
}
public List<chartObject> children { get; set; }
public void AddChild(chartObject child) {
child._parent = this;
children.Add(child);
chartObject tmp = this;
while (tmp != null) {
tmp._descCache = null;
tmp = tmp._parent;
}
}
private int calcDescendents() {
return children.Count+children.Sum(child => child.descendants);
}
}
Walk all nodes of the tree (depth first is ok) and when done with children set "descendants property to sum of children's descendants + child count. You have to do it on every change to the tree structure. You should be able to limit updates only to parents of element that is changed.
If nodes made immutable you can populate the field at creation time.
Side notes:
Your tree is mutable as it is now (one can easily add more child nodes anywhere), so it may be safer to have method that counts descendants instead of property on a node.
Having computed property int descendants { get; set; } to be read/write is confusing as anyone can set its value to whatever number. Consider if making it read only and updating when one of child nodes changes (requires some custom notification mechanism).
Code style - consider naming classes with upper case names for code that is intended to be public (follow Microsoft's C# coding guidelines). chartObject -> ChartObject
I am creating a new project type using MPF.
I want to create a type of node where the backing for that node doesn't actually exist anywhere. To keep it simple, I just want to generate the captions on the fly.
I have created a new node subclass from HierarchyNode because it will eventually have children. I have subclassed the FolderNode so I can determine which folders will have these virtual nodes as children. I am using Get/SetMetadata to do that and it works fine. I overrode GetProperty in MyFolderNode so that if the folder type is a "normal" folder, it just routes to base. Otherwise it returns a VirtualNode for FirstChild. The VirtualNodes create their next sibling and set NextSibling to it. TL;DR: Code follows.
My problem is that it isn't working. Specifically, when I click on the "Expand this folder" icon, it turns blue (so the click is registering) but it stays blue and the node isn't expanded. Debugging shows that trying to expand the folder does hit GetProperty requesting FirstChild and it does return the id of the first child. After that the VirtualNode is queried twice to see if it is expandable. Then it is queried for the caption. Then the icon. Then nothing.
Here is the code for my FolderNode subclass:
public class AndroidFolderNode : FolderNode
{
public enum FolderType
{
Normal,
JavaSource
}
public string[] VirtualNodes = new[]
{
"Virtual Node One",
"Virtual Node Two",
"Virtual Node Three"
};
private FolderType mFolderType;
public FolderType Type
{
get
{
return mFolderType;
}
set
{
if (mFolderType != value)
{
mFolderType = value;
OnInvalidateItems(this);
}
}
}
private HierarchyNode mVirtualChild;
public AndroidFolderNode(ProjectNode root, string relativePath, ProjectElement element)
: base(root, relativePath, element)
{
var t = element.GetMetadata("Type");
if (string.IsNullOrWhiteSpace(t))
{
Type = FolderType.Normal;
}
else
{
FolderType tempType;
if (Enum.TryParse(t, true, out tempType))
{
Type = tempType;
}
}
}
protected override NodeProperties CreatePropertiesObject()
{
return new AndroidFolderNodeProperties(this);
}
public override object GetProperty(int propId)
{
object result = null;
switch ((__VSHPROPID) propId)
{
case __VSHPROPID.VSHPROPID_FirstChild:
goto case __VSHPROPID.VSHPROPID_FirstVisibleChild;
case __VSHPROPID.VSHPROPID_FirstVisibleChild:
if (Type == FolderType.Normal)
{
result = (int)((this.FirstChild != null) ? this.FirstChild.ID : VSConstants.VSITEMID_NIL);
}
else
{
if (mVirtualChild == null)
{
mVirtualChild = new VirtualFolderNode(this, 0);
}
result = mVirtualChild.ID;
}
break;
default:
result = base.GetProperty(propId);
break;
}
return result;
}
}
Here is the code for my VirtualNode:
class VirtualFolderNode : HierarchyNode
{
private static Guid _guid = new Guid("DD264E51-2E66-4BCC-A8A6-DE3BDE890DED");
private int mIdx;
private AndroidFolderNode mParent;
private VirtualFolderNode mSibling;
public VirtualFolderNode(AndroidFolderNode parent, int idx)
: base(parent.ProjectMgr)
{
mParent = parent;
mIdx = idx;
Parent = parent;
if (idx < parent.VirtualNodes.Length)
{
mSibling = new VirtualFolderNode(parent, idx + 1);
NextSibling = mSibling;
}
}
public override string Url
{
get { return Parent.Url + "\\VNode" + mIdx; }
}
public override string Caption
{
get { return mParent.VirtualNodes[mIdx]; }
}
public override Guid ItemTypeGuid
{
get { return _guid; }
}
}
Got it! (Side note: I've never had to answer my own question before.)
The problem, it appears, is that the HierarchyNode.GetIconHandle(bool open) simply returns null. Overriding GetIconHandle in VirtualNode allows it to be displayed as expected. So I added this to VirtualNode and bada bing, bada boom:
public override object GetIconHandle(bool open)
{
return ProjectMgr.ImageHandler.GetIconHandle(open ? (int)ProjectNode.ImageName.OpenFolder : (int)ProjectNode.ImageName.Folder);
}