Hello I currently have a TreeView with the following structure:
Root
Child
Root
Child
Root
Child
Child
RootN
ChildN
The TreeView structure can basically have NRootNodes - NChildren and the NRootNodes can have NRoots and NChildren so basically just like Windows Explorer Window.
My current issue that I have is that I have to get all the Parents or Root, in this case Roots / RootN and then I have to Remove all of their Child Nodes, in this case Child / ChildN. In the end I have to have only the Parent Nodes and then Clone them so I can move them to a different location within the TreeView.
RootNodes have a unique Tag - Folder and ChildNodes have another unique Tag - Calculations, as I have said earlier, I have to get rid of all Calculations in the Selected Node so only the Structure of that Selected Node will Remain.
Basically in the end I have to have something like this:
Root
Root
Root
Root
Root
I have a recursive method that "scans" the SelectedNode and gets all the Parents:
public List<TreeNode> CollectParentNodes(TreeNodeCollection parentCollection, List<TreeNode> collectedNodes)
{
foreach (TreeNode node in parentCollection)
{
if (!collectedNodes.Contains(node.Parent))
{
collectedNodes.Add(node.Parent);
parentNodeAdded = true;
}
if (node.Level != 0 && node.Tag.ToString() != Enumerations.NodeType.Calculation.ToString())
collectedNodes.Add(node);
if (node.Nodes.Count > 0)
CollectParentNodes(node.Nodes, collectedNodes);
}
parentNodeAdded = false;
return collectedNodes;
}
In the end I have a List that will hold all the Parents but the problem I'm facing is that that Parents also contain their descendents, in this case the Calculations
I have searched Google and StackOverFlow but I could not find anything of help, I appologize in advance if this has already been answered.
Thank you.
You can create an extension method GetAllNodes for TreeView that return List
Remember using using System.Linq; at top of your code
public static class Extensions
{
public static List<TreeNode> GetAllNodes(this TreeView tree)
{
var firstLevelNodes = tree.Nodes.Cast<TreeNode>();
return firstLevelNodes.SelectMany(x => GetNodes(x)).Concat(firstLevelNodes).ToList();
}
private static IEnumerable<TreeNode> GetNodes(TreeNode node)
{
var nodes = node.Nodes.Cast<TreeNode>();
return nodes.SelectMany(x => GetNodes(x)).Concat(nodes);
}
}
And the usage will be:
var result = this.treeView1.GetAllNodes().Where(x => x.Tag == "FOLDER").ToList();
Remember to add namespace of your extensions class at top of your code wherever you want to use it.
As an example you can set All nodes with tag of Folder to be in Red forecolor:
var result = this.treeView1.GetAllNodes().Where(x => (x.Tag as string) == "FOLDER").ToList();
result.ForEach(x => x.ForeColor = Color.Red);
And here is an Screenshot
This will create a new tree with the selected node as root and which child nodes consists only of nodes that are tagged "Folder".
You need to create a copy constructor (or extension method) to deep copy the node to prevent the manipulation on the node objects to impact your original tree source:
public TreeNode CollectFolderChildNodes(TreeNode selectedNode)
{
if (selectedNode.Tag == "Calculation")
return null;
// Get all the children that are tagged as folder
var childRootNodes = selectedNode.Children.Where((childNode) => childNode.Tag == "Folder";
// Clone root node using a copy constructor
var newRoot = new TreeNode(selectedNode);
newRoot.Children.Clear();
foreach (var childNode in childRootNodes)
{
// Iterate over all children and add them to the new tree
if (childNode.Children.Any())
{
// Repeat steps for the children of the current child.
// Recursion stops when the leaf is reached
newRoot.Children.Add(CollectFolderChildNodes(childNode));
}
else
{
// The current child item is leaf (no children)
newRoot.Children.Add(new TreeNode(childNode));
}
}
return newRoot;
}
I think this should do it, but I didn't tested it. But maybe at least the idea behind it is clear.
But as I mentioned before, maybe it's better to traverse the tree (using same ItemsSource) and set a property (e.g. IsHidingCalculations) to true so that only the folders will show up. You would need to implement an ItemsStyle and use a trigger that sets the items Visibility to Collapsed when your IsHidingCalculations evaluates to true.
To clone a node without its children you can create an extension method like this:
public static TreeNode CloneWithoutChildren(this TreeNode node)
{
return new TreeNode(node.Text, node.ImageIndex, node.SelectedImageIndex)
{
Name = node.Name,
ToolTipText = node.ToolTipText,
Tag = node.Tag,
Checked = node.Checked
}
}
and then:
collectedNodes.Add(node.CloneWithoutChildren());
Related
I need to filter Tree on Winforms.
basically the Tree View contain the list from the registry with all the key's on the branch
now,when i run the method to search some values in all the tree, the result I get is just part of the tree and I cant save the branch were connected from the result to the root.
there is any way to save the hierarchy that in the end the result will showed correctly. ?
I tried to put it on Dictionary that contains string with the level,index, and full path. any idea?
this is the search code.the Dictionary basically to show the results. for testing
Dictionary<string, TreeNode> Result = new Dictionary<string, TreeNode>();
private void SearchforNodes(TreeNodeCollection nodes)
{
bool x = true;
while (x)
{
foreach (TreeNode item in nodes)
{
x = ReadAllKeys(item);
}
}
}
bool flag = true;
private bool ReadAllKeys(TreeNode node)
{
foreach (TreeNode item in node.Nodes)
{
if (item.Nodes.Count > 0)
{
ReadAllKeys(item);
}
else
{
var result = SearchKey(item);
if (result != null)
{
if (!Result.Keys.Contains(string.Format("Index: {0} level: {1} Text: {2} FullPathTree: {3} ", result.Index, result.Level, result.Text, result.FullPath)))
{
Result.Add(string.Format("Index: {0} level: {1} Text: {2} FullPathTree: {3} ", result.Index, result.Level, result.Text, result.FullPath), result);
flag = false;
}
else
{
flag = false;
}
}
}
}
return flag;
}
private TreeNode SearchKey(TreeNode node)
{
if (node.Text.ToUpper().Contains(txtSearch.Text.ToUpper()))
{
return node;
}
else
{
return null;
}
}
For what I remember in using the Treeviews, in the class/classes used to contain the data used for the tree we usually added a Parent or a ParentID field so that each node until the leaf knows who is it's parent.
this is useful to set which nodes other than the leaf must be visible.
Our data class was usually in a datatable or a collection but also always put in the tag element of the treenode to be able to have access to all information from the node. (the Tag is an object so you can attach your classes or datarows and then retrieve them with a cast)
If you just use the standard node element in the tree as your data source, I'm sure the node has a Parent information so that you can add to the collection of the visible elements you want to display after filtering all the elements up to the root.
Another thing I found useful when working with tree data is to have a plain collection of all the nodes for example a List updated when building the tree and, use that collection to set the visibility of the node and its parents, ancestors and so on.
I'm not sure this is exactly what you need but I hope it can set you to the right path.
This question is a follow up to this question. Basically what I want to do is add nodes to my treeView in numerical order. Right now I am working with a list of child nodes. Each child has a DisplayName of a numerical value. In my program I have a loop that checks if the node being added has a DisplayName that is less than the DisplayName of the current child in the loop. If the new child's DisplayName is less than the child being checked I would like to add the new node before the already existing one. I am having trouble figuring out a method to do this.
Here is my code:
var node = Data.GetAllChildren(x => x.Children).Distinct().ToList().First(x => x.identify == 'B');
//Get # of children -- if children exist
if (node.Children.Count() > 0)
{
newChildTitle = int.Parse(nodeName.Value); //node to add
for (int i = 0; i < node.Children.Count(); i++)
{
currentChildTitle = int.Parse(node.Children.ElementAt(i).DisplayName.Value); //current node value
if (newChildTitle == currentChildTitle) //Check if location already exists
{
MessageBox.Show("Sorry, that location name already exists under this category.", "Duplicate Location Name", MessageBoxButton.OK, MessageBoxImage.Warning);
break;
}
else if (newChildTitle < currentChildTitle) //If new location value is less, add before current location in Tree
{
//CODE WOULD GO HERE**
break;
}
}
}
else //if no children exist, just add
node.Children.Add(CreateBlockingLocation(model, blockTreeCollection, nodeName));
XAML of the TreeView (the TreeView is bound to an ObservableCollection):
<!-- Tree view items & Functions -->
<TreeView Name="Tree_One" IsEnabled="{Binding DataContext.DataTreeEnabled, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}" ItemsSource="{Binding DataTree.Data}" />
Data and Properties of the ObservableCollection<HierarchicalVM> that the TreeView is bound to:
private HierarchicalVM _parent;
private ObservableCollection<HierarchicalVM> _children;
public HierarchicalVM()
{
Commands = new ObservableCollection<Command>();
}
//Relationship Properties
public HierarchicalVM Parent
{
get { return _parent; }
set
{
_parent = value;
NotifyPropertyChange(() => Parent);
}
}
public ObservableCollection<HierarchicalVM> Children
{
get { return _children ?? (_children = new ObservableCollection<HierarchicalVM>()); }
set { _children = value; }
}
Current Solution attempt:
//Gets parent item (Data is the complete Tree)
var node = Data.GetAllChildren(x => x.Children).Distinct().ToList().First(x => x.identify == 'B');
if (!node.Children.Any(n => n.numValue == newNumValue))
{
//Error is on this line: **Operator '.' cannot be applied to operand of type 'void'
node.Children = node.Children.Add(newNode).Orderby(n => n.numValue);
}
Ok, assuming you already have a reference to the Parent object (not the DataTreeItem UI Element), there are two ways I can think of to accomplish this. This is off the top of my head with a little bit of checking against MSDN, so I apologize for any bugs.
Parent parent = //however you are getting the parent
if (!parent.Children.Any(n => n.DisplayName == newNode.DisplayName))
{
parent.Children.Add(newNode)
parent.Children = new ObservableCollection<ViewModel>(parent.Children.OrderBy(n => n.DisplayName));
//OR,
parent.Children.InsertItem(parent.Children.IndexOf(parent.Children.OrderBy(n => n.DisplayName).Last(n => n.DisplayName < newNode.DisplayName)), newNode);
}
The first method just adds the new item and resorts the list, which gets you the same result as an in-place insert. The second actually does a in-place insert, but is more complicated because you have to find the index to insert at.
If the list is already sorted you could remove the OrderBy in the second method. This also assumes that DisplayName is an int and a property of each child node (which from the code you posted it isn't, but it should be).
Clearly I don't understand your architecture, so I will explain how I think it should be, and then perhaps you can discover where your code is broken.
We have a object type called Parent, which contains a collection called children, like so:
class Parent<T>
{
ObservableCollection<T> Children;
}
Now we have an collection of Parent called Data in the view model that the TreeView is bound to. Somehow, we are getting a single instance of this Parent class (which definitely shouldn't be void, the fact that your "node.Children" object is should be a HUGE red flag).
If you agree with what I said above, the insert code I posted should work.
Please let me know if I can clarify or add to this answer, or help in any other way.
Let's say I've got tree with 3 categories, each with 3 child nodes. I want to delete root node, when all child nodes gets deleted. I tried something like this:
TreeNode current = treeView1.SelectedNode;
TreeNode parent = treeView1.SelectedNode.Parent;
if (parent.Nodes.Count == 0)
{
parent.Nodes.Remove(current);
}
And I placed it in Form1_Load. Unfortunatelly, when all child nodes are gone nothing happens. Is this code correct? Or maybe I misplaced it and I should place it somewhere else?
edit: My tree looks like this:
Morning
brush teeth
drink coffee
Afternoon
dinner
TV
Night
Sleep
So if I decide to delete "Sleep", I want also delete "Night". But If I decide to delete "TV", I want to keep "Dinner" and "Afternoon".
Try this:
if (treeView1.SelectedNode != null)
{
if (treeView1.SelectedNode.Parent == null) treeView1.SelectedNode.Remove();
else if (treeView1.SelectedNode.Parent.Nodes.Count == 1) treeView1.SelectedNode.Parent.Remove();
else treeView1.SelectedNode.Remove();
}
If the parent is null, then you know that you are on a root node. So that node needs to be removed from the TreeView's Nodes collection directly. Otherwise, you can just remove the selected node from the parent. There's no reason to even look at the Node count.
Now, you also need to check that the current node is not null either; because it's perfectly reasonable to have no node in a tree selected.
TreeNode current = treeView1.SelectedNode;
if(current == null)
return;
TreeNode parent = treeView1.SelectedNode.Parent;
if (parent == null)
{
treeView1.Nodes.Remove(current);
}
else
{
parent.Nodes.Remove(current);
}
I am working on an ASP.Net page, and there is tree view in it. In the tree view some nodes have nested nodes like branches. I have data in a list of custom objects in the following format:
Id, Description, parentId
Right now, I am using a function to recursively add nodes to the tree view. The following is code snippet:
private bool findParentAddNode(string id, string description, string parentid, ref List<CustomTreeNode> treeList)
{
bool isFound = false;
foreach (CustomTreeNode node in treeList)
{
if (node.id == parentid)//if current node is parent node, add in it as its child
{
node.addChild(id, description, parentid);
isFound = true;
break;
}
else if (node.listOfChildNodes != null)//have child nodes
{
isFound = findParentAddNode(id, description, parentid, ref node.listOfChildNodes);
if (isFound)
break;
}
}
return isFound;
}
The above technique works well but, for more then 30K nodes, its performance is slow. Please suggest an algorithm to replace this recursive call with loops.
As it recurses down the tree, the code is doing a linear search over the lists of child nodes.
This means that for randomly distributed parent ids, after adding N nodes to the tree it will on average search N/2 nodes for the parent before adding the N+1th node. So the cost will be O(N²) on the number of nodes.
Instead of a linear scan, create an index of id to node and use that to find the parent quickly. When you create a node and add it to the tree, also add it to a Dictionary<int,CustomTreeNode>. When you want to add a node to parent, find the parent in the index and add it. If addChild returns the child it creates, then the code becomes:
Dictionary<int,CustomTreeNode> index = new Dictionary<int,CustomTreeNode>();
private bool findParentAddNode(string id, string description, string parentid)
{
if ( !nodeIndex.TryGetValue ( parentid, out parentNode ) )
return false;
index[id] = parentNode.addChild(id, description, parentid);
return true;
}
You will need to add the root of the tree to the index before using findParentAddNode.
An iterative version of a breadth-first search should be something like the following:
var rootNodes = new List<CustomTreeNode> { new CustomTreeNode() };
while (rootNodes.Count > 0) {
var nextRoots = new List<CustomTreeNode>();
foreach (var node in rootNodes) {
// process node here
nextRoots.AddRange(node.CustomTreeNode);
}
rootNodes = nextRoots;
}
That said, this isn't tested, and since it's a BFS, isn't optimal w/r/t memory. (Memory use is O(n), not O(log n) compared to DFS or iterative-deepening DFS.)
You can return data in xml format from sql server database using for xml
then bind it to treeview control.
I'm trying to represent a subway map type thing that has to be drawn progressively (like its growing).
My code all works perfectly but its unreadable. Basically it's a tree structure with recursive nodes and subnodes and my test code looks like this:
Children.Add(new TrackLine(800));
Children[0].Children.Add(new TrackSpot());
Children[0].Children[0].Children.Add(new TrackSplitter());
Children[0].Children[0].Children[0].Children.Add(new TrackRotate(-45));
Children[0].Children[0].Children[0].Children[0].Children.Add(new TrackColorChange(Color.Red));
Children[0].Children[0].Children[0].Children[0].Children[0].Children.Add(new TrackLine(100));
Children[0].Children[0].Children[0].Children[0].Children[0].Children[0].Children.Add(new TrackRotate(45));
Children[0].Children[0].Children[0].Children[0].Children[0].Children[0].Children[0].Children.Add(new TrackLine(200));
Does anyone have any suggestions of how to fix that mess?
You're looking for a way to add it to the deepest child that has no children of it's own?
class Node
{
List<Node> children ;
public void addNode( Node newNode )
{
if( children.Count > 0 )
children[0].addNode( newNode ) ; // recursive call
// to ask first child to add newNode to it
else
children.Add( newNode ) ; // just add it to the children list of THIS node
}
}
To make that code more readable I'd use variables with appropriate names (since I don't know your subject domain, mine are probably not appropriate):
Children.Add(new TrackLine(800));
var lineA = Children[0];
lineA.Children.Add(new TrackSpot());
var spotA = lineA.Children[0];
spotA.Children.Add(new TrackSplitter());
var splitterA = spotA.Children[0];
splitterA.Children.Add(new TrackRotate(-45));
var rotateNeg45 = splitterA.Children[0];
rotateNeg45.Children.Add(new TrackColorChange(Color.Red));
var colorRed = rotateNeg45.Children[0];
colorRed.Add(new TrackLine(100));
var lineB = colorRed.Children[0];
lineB.Children.Add(new TrackRotate(45));
var rotatePos45 = lineB.Children[0];
rotatePos45.Children.Add(new TrackLine(200));
var lineC = rotatePos45.Children[0];
Another approach is to use strings as indexes for Children like this:
Children.Add(new TrackLine(800));
Children["lineA"].Children.Add(new TrackSpot());
Children["lineA"].Children["spotA"].Children.Add(new TrackSplitter());
However I probably would not do it because managing the string constants would be a mess on its own and it would probably require changing Children implementation.