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Getting all visible Nodes in a TreeView

I want to get the node's keys just 'only in view' on treeview.
Here is the example;
I am using below code to get all node recursively. It just return all nodes key as expected. however i need to get the keys that only in treeview's view;
public void PrintNodesRecursive(UltraTreeNode oParentNode)
{
if (oParentNode.Nodes.Count == 0)
{
return;
}
foreach (UltraTreeNode oSubNode in oParentNode.Nodes)
{
MessageBox.Show(oSubNode.Key.ToString());
PrintNodesRecursive(oSubNode);
}
}
private void ultraButton3_Click(object sender, EventArgs e)
{
PrintNodesRecursive(ultraTree1.Nodes[0]);
}
I don't know i should follow different path or just reorganize code.
I just stacked after many hours. Need your help.

You can find the first visible node using Nodes collection and IsVisible property of the Node. Then create a recursive method which uses NextVisibleNode to find the next visible node in TreeView.
private void button1_Click(object sender, EventArgs e)
{
var visibleNodes = GetVisibleNodes(treeView1).ToList();
}
public IEnumerable<TreeNode> GetVisibleNodes(TreeView t)
{
var node = t.Nodes.Cast<TreeNode>().Where(x => x.IsVisible).FirstOrDefault();
while (node != null)
{
var temp = node;
node = node.NextVisibleNode;
yield return temp;
}
}
Also as another option, you can rely on Descendants extension method to flatten the TreeView and then using IsVisible property, get all visible nodes.

Copy all Selected (Checked) TreeNodes from one treeview to another (include unchecked parents) C#

I've created a directory and file browser TreeView on the left side. I want the users to be able to browse the tree and check the files and directories that they would like to move to another treeview.
The other TreeView is a user control I found online called TreeViewColumn. I will be using that control to allow the user to add other data (categories, attributes) to the files and folders selected.
The trouble I'm running into is two-fold, I need to recursively add all children (I can figure this out) but I need to add unchecked parents to checked children (to preserve the hierarchy).
private void IterateTreeNodes(TreeNode originalNode, TreeNode rootNode)
{
//Take the node passed through and loop through all children
foreach (TreeNode childNode in originalNode.Nodes)
{
// Create a new instance of the node, will need to add it to the recursion as a root item
// AND if checked it needs to get added to the new TreeView.
TreeNode newNode = new TreeNode(childNode.Text);
newNode.Tag = childNode.Tag;
newNode.Name = childNode.Name;
newNode.Checked = childNode.Checked;
if (childNode.Checked)
{
// Now we know this is checked, but what if the parent of this item was NOT checked.
//We need to head back up the tree to find the first parent that exists in the tree and add the hierarchy.
if (tvSelectedItems.TreeView.Nodes.ContainsKey(rootNode.Name)) // Means the parent exist?
{
tvSelectedItems.TreeView.SelectedNode = rootNode;
tvSelectedItems.TreeView.SelectedNode.Nodes.Add(newNode);
}
else
{
AddParents(childNode);
// Find the parent(s) and add them to the tree with their CheckState matching the original node's state
// When all parents have been added, add the current item.
}
}
IterateTreeNodes(childNode, newNode);
}
}
private TreeNode AddParents(TreeNode node)
{
if (node.Parent != null)
{
//tvDirectory.Nodes.Find(node.Name, false);
}
return null;
}
Could anyone help with this code so that it recursively adds checked nodes (and their parent, regardless of checked state). I need to maintain directory hierarchy.
Thanks for any help!

A rather (not-so-clean and not-preferred) solution could be to clone the tree first, and then remove unchecked branches.
Else, when you are adding a node, write a recursive method to traverse through node's parent node until you hit the root. And simply optimize it by checking if childNode.parent already exists, just ignore the branch and move on. i.e. Backtrack to root node.

I got it working. I was already aware of what #Yahya was saying, I was hoping for an easier way / better approach.
The code below is certainly not optimal, I will continue improving it on my end but at this point it is looking through a treeview on the left and copying all of the checked items (and their parents - regardless of CheckedState) to a treeview on the right.
Hopefully this helps someone and thanks for answering #Yahya.
I'm open to improvements but keep in mind this is a one-time use utility.
private void cmdMoveRight_Click(object sender, EventArgs e)
{
tvSelectedItems.TreeView.Nodes.Clear();
// Traverse first level Tree Nodes
foreach (TreeNode originalNode in tvDirectory.Nodes)
{
TreeNode newNode = new TreeNode(originalNode.Text);
newNode.Name = originalNode.Name;
newNode.Tag = originalNode.Tag;
newNode.Checked = originalNode.Checked;
//Only add to the new treeview if the node is checked
if (originalNode.Checked)
{
tvSelectedItems.TreeView.Nodes.Find(originalNode.Parent.Name,true)[0].Nodes.Add(newNode);
}
//Start recursion - this will be called for each first level node - there should technically only be 1 "ROOT" node.
IterateTreeNodes(originalNode, newNode);
}
}
private void IterateTreeNodes(TreeNode originalNode, TreeNode rootNode)
{
//Take the node passed through and loop through all children
foreach (TreeNode childNode in originalNode.Nodes)
{
// Create a new instance of the node, will need to add it to the recursion as a root item
// AND if checked it needs to get added to the new TreeView.
TreeNode newNode = new TreeNode(childNode.Text);
newNode.Tag = childNode.Tag;
newNode.Name = childNode.Name;
newNode.Checked = childNode.Checked;
if (childNode.Checked)
{
// Now we know this is checked, but what if the parent of this item was NOT checked.
//We need to head back up the tree to find the first parent that exists in the tree and add the hierarchy.
TreeNode[] nodestest = tvSelectedItems.TreeView.Nodes.Find(childNode.Parent.Name, true);
if (nodestest.Length > 0)
{
tvSelectedItems.TreeView.Nodes.Find(childNode.Parent.Name,true)[0].Nodes.Add(newNode);
}
else
{
AddParents(childNode);// Find the parent(s) and add them to the tree with their CheckState matching the original node's state
}
}
//recurse
IterateTreeNodes(childNode, newNode);
}
}
private void AddParents(TreeNode node)
{
if (node.Parent != null)// Check if parent is null (would mean we're looking at the root item
{
TreeNode[] nodestest = tvSelectedItems.TreeView.Nodes.Find(node.Parent.Name, true);
if (nodestest.Length > 0)
{
TreeNode[] nodes = tvDirectory.Nodes.Find(node.Name, true);
TreeNode newNode = new TreeNode(nodes[0].Text);
newNode.Name = nodes[0].Name;
newNode.Tag = nodes[0].Tag;
newNode.Checked = nodes[0].Checked;
tvSelectedItems.TreeView.Nodes[node.Parent.Name].Nodes.Add(newNode);
}
else
{
AddParents(node.Parent);
TreeNode newNode = new TreeNode(node.Text);
newNode.Name = node.Name;
newNode.Tag = node.Tag;
newNode.Checked = node.Checked;
tvSelectedItems.TreeView.Nodes.Find(node.Parent.Name,true)[0].Nodes.Add(newNode);
}
}
else // deal with root node
{
TreeNode rootNode = new TreeNode(node.Text);
rootNode.Name = node.Name;
rootNode.Tag = node.Tag;
rootNode.Checked = node.Checked;
tvSelectedItems.TreeView.Nodes.Add(rootNode);
}
}

Select TreeView Node

I've a TreeNode and I need to allow user to select only one child node for parent.
Example:
-Car
---Ferrari
---Lamborghini
---Porsche
-Shoes
---Nike
---Puma
---Adidas
I can select "Ferrari" and "Nike", but not other child in "Car" or "Shoes". How can I make it?
After I do this, I need to concat text of Parent and child like this: Car: Ferrari.
Can you help me?
Regards.

You could handle the BeforeCheck event and clear the siblings checkboxes, e.g. :
private bool skipEvents = false; // this flag to avoid infinite recursion
void treeView1_BeforeCheck(object sender, TreeViewCancelEventArgs e)
{
// if is a root (car or shoes), or it's a recursive call, just return
if (skipEvents || e.Node.Parent == null)
return;
skipEvents = true;
foreach (TreeNode sibling in e.Node.Parent.Nodes)
{
// set the other siblings to unchecked
if (sibling != e.Node)
sibling.Checked = false;
}
skipEvents = false;
}
Here's an example to concatenate the parents and childs selected:
public string GetSelectionString()
{
string categorySep = Environment.NewLine;
string parentChildSep = " : ";
StringBuilder sb = new StringBuilder();
foreach (TreeNode root in this.treeView1.Nodes)
{
foreach (TreeNode node in root.Nodes)
{
if (node.Checked)
{
if (sb.Length > 0)
sb.Append(categorySep);
sb.Append(root.Text);
sb.Append(parentChildSep);
sb.Append(node.Text);
break;
}
}
}
return sb.ToString();
}
for example if Ferrari and Puma are selected, it returns a string like this:
Car : Ferrari
Shoes : Puma
EDIT as per comment:
This code does what you ask in your comment (selection/deselection of parents children):
private bool skipEvents = false; // this flag to avoid infinite recursion
void treeView1_BeforeCheck(object sender, TreeViewCancelEventArgs e)
{
// if it's a recursive call, just return
if (skipEvents)
return;
skipEvents = true;
// it's a root (e.g. car or shoes)
if (e.Node.Parent == null)
{
// if root node is going to be checked, just cancel the action (i.e. block parent selection)
if (!e.Node.Checked)
{
e.Cancel = true;
}
}
else
{
foreach (TreeNode sibling in e.Node.Parent.Nodes)
{
// set the other siblings to unchecked
if (sibling != e.Node)
sibling.Checked = false;
}
}
skipEvents = false;
}
void treeView1_AfterCheck(object sender, TreeViewEventArgs e)
{
// if it's a recursive call, just return
if (skipEvents)
return;
this.skipEvents = true;
// it's a root (e.g. car or shoes)
if (e.Node.Parent == null)
{
// root node has been unchecked, so uncheck the children
if (!e.Node.Checked)
{
foreach (TreeNode child in e.Node.Nodes)
child.Checked = false;
}
}
else
{
// if a child node has been checked --> check the parent
// otherwise, uncheck the parent
e.Node.Parent.Checked = e.Node.Checked;
}
this.skipEvents = false;
}
N.B.
TreeView class has a known bug that arises in Vista/Windows7 concerning checkboxes.
Basically if you double-click a checkbox it doesn't lauch any event, so this management will be compromised.
To solve this issue, you can disable double-click by using the class explained in this post instead of TreeView.

If you need one selection per tree, I would suggest using two TreeViews. I would also question whether or not you need to be using TreeViews or whether two ListBoxes or ComboBoxes might be more appropriate.
If you don't know how many 'trees' you'll have, but you do know how deep they are, you could use two or more ListBoxes (or ListViews) to display basically a list of lists:
Categories:
Shoes: Nike
Cars: Ferrari
Fruits: Apple (selected)
Selected Category (Fruits):
Apple (selected)
Orange
Pear
Kiwi

How to select a node of treeview programmatically in c#?

Used treeview.SelectedNode to select a child node. How to invoke treeview.AfterSelect event when a node is selected programmatically?
this.treeView1.SelectedNode = this.treeView1.Nodes[0].Nodes[0].Nodes[0].Nodes[0];
if (this.treeView1.Nodes[0].Nodes[0].Nodes[0].Nodes[0].IsSelected)
{
MessageBox.Show("Node is selected");
}

Apologies for my previously mixed up answer.
Here is how to do:
myTreeView.SelectedNode = myTreeNode;
(Update)
I have tested the code below and it works:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
treeView1.Nodes.Add("1", "1");
treeView1.Nodes.Add("2", "2");
treeView1.Nodes[0].Nodes.Add("1-1", "1-1");
TreeNode treeNode = treeView1.Nodes[0].Nodes.Add("1-2", "1-3");
treeView1.SelectedNode = treeNode;
MessageBox.Show(treeNode.IsSelected.ToString());
}
}

treeViewMain.SelectedNode = treeViewMain.Nodes.Find(searchNode, true)[0];
where searchNode is the name of the node.
I'm personally using a combo "Node + Panel" where Node name is Node + and the same tag is also set on panel of choice.
With this command + scan of panels by tag i'm usually able to work a treeview+panel full menu set.

Call the TreeView.OnAfterSelect() protected method after you programatically select the node.

yourNode.Toggle(); //use that function on your node, it toggles it

TreeViewItem tempItem = new TreeViewItem();
TreeViewItem tempItem1 = new TreeViewItem();
tempItem = (TreeViewItem) treeView1.Items.GetItemAt(0); // Selecting the first of the top level nodes
tempItem1 = (TreeViewItem)tempItem.Items.GetItemAt(0); // Selecting the first child of the first first level node
SelectedCategoryHeaderString = tempItem.Header.ToString(); // gets the header for the first top level node
SelectedCategoryHeaderString = tempItem1.Header.ToString(); // gets the header for the first child node of the first top level node
tempItem.IsExpanded = true; // will expand the first node

private void btn_CollapseAllAndExpandFirstLevelUnderRoot(object sender, EventArgs e)
{
//this example collapses everything, then expands the first level under the root node.
tv_myTreeView.CollapseAll();
TreeNode tn = tv_myTreeView.Nodes[0];
tn.Expand();
}

Move Node in Tree up or Down

What is the most accurate way to move a node up and down in a treeview. I got a context menu on each node and the selected node should be moved with all its subnodes.
I'm using C# .Net 3.5 WinForms

You can use the following extensions :
public static class Extensions
{
public static void MoveUp(this TreeNode node)
{
TreeNode parent = node.Parent;
TreeView view = node.TreeView;
if (parent != null)
{
int index = parent.Nodes.IndexOf(node);
if (index > 0)
{
parent.Nodes.RemoveAt(index);
parent.Nodes.Insert(index - 1, node);
}
}
else if (node.TreeView.Nodes.Contains(node)) //root node
{
int index = view.Nodes.IndexOf(node);
if (index > 0)
{
view.Nodes.RemoveAt(index);
view.Nodes.Insert(index - 1, node);
}
}
}
public static void MoveDown(this TreeNode node)
{
TreeNode parent = node.Parent;
TreeView view = node.TreeView;
if (parent != null)
{
int index = parent.Nodes.IndexOf(node);
if (index < parent.Nodes.Count -1)
{
parent.Nodes.RemoveAt(index);
parent.Nodes.Insert(index + 1, node);
}
}
else if (view != null && view.Nodes.Contains(node)) //root node
{
int index = view.Nodes.IndexOf(node);
if (index < view.Nodes.Count - 1)
{
view.Nodes.RemoveAt(index);
view.Nodes.Insert(index + 1, node);
}
}
}
}
Child nodes will follow their parents.
EDIT: Added case that node to move is a root in the TreeView.

While I feel writing this code is a waste of time, given the lack of response to comments by the OP, the least I can do is show how the code example by Le-Savard can be fixed so that muliple clicks of the up or down choice on the context menu ... assuming the context menu is not auto-closed each time and the user is forced to select the same node over and over again ... will do the right thing with the orignally selected node, and not create un-intended side effects :
public static class Extensions
{
public static void MoveUp(this TreeNode node)
{
TreeNode parent = node.Parent;
if (parent != null)
{
int index = parent.Nodes.IndexOf(node);
if (index > 0)
{
parent.Nodes.RemoveAt(index);
parent.Nodes.Insert(index - 1, node);
// bw : add this line to restore the originally selected node as selected
node.TreeView.SelectedNode = node;
}
}
}
public static void MoveDown(this TreeNode node)
{
TreeNode parent = node.Parent;
if (parent != null)
{
int index = parent.Nodes.IndexOf(node);
if (index < parent.Nodes.Count - 1)
{
parent.Nodes.RemoveAt(index);
parent.Nodes.Insert(index + 1, node);
// bw : add this line to restore the originally selected node as selected
node.TreeView.SelectedNode = node;
}
}
}
}
Of course this fix, still does not address the fact that in the example code that multiple root nodes cannot be moved (since they are 'parentless) : that's easiliy fixable.
Nor does it address the more interesting case where moving up a top child-node means you make some interpretation of where that "promoted" child code should go : exactly the same "strategic choice" is involved where you "move down" the last child node of a parent node and are thus required to decide where it should go. In Dynami Le-Savard's code : these cases are just ignored.
However, it is a design-choice to restrict child node from only being moved within their parent nodes Nodes collection : a design choice that may be perfectly suitable for one solution.
Similarly, it is a design choice to force a user to select a node and context-click to get a context menu that allows a choice of moving up or down every single time they want to move it : that's not a design choice I'd make : I'd be using drag-and-drop here or buttons that allow repeated rapid-fire relocation of any selected node anywhere in the tree.
By the way I like Dynami Le-Savard's use of extensions here.

Here's a solution that allows you to drag & drop nodes to wherever you want. To move a node to the same level as another node, just hold down shift when dropping the node. This is a really easy way to go compared to the alternatives and their potential problems. Example was written with a more recent version of .Net (4.5).
Note: Be sure and AllowDrop=true on the treeview control otherwise you can't drop nodes.
/// <summary>
/// Handle user dragging nodes in treeview
/// </summary>
private void treeView1_ItemDrag(object sender, ItemDragEventArgs e)
{
DoDragDrop(e.Item, DragDropEffects.Move);
}
/// <summary>
/// Handle user dragging node into another node
/// </summary>
private void treeView1_DragEnter(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Move;
}
/// <summary>
/// Handle user dropping a dragged node onto another node
/// </summary>
private void treeView1_DragDrop(object sender, DragEventArgs e)
{
// Retrieve the client coordinates of the drop location.
Point targetPoint = treeView1.PointToClient(new Point(e.X, e.Y));
// Retrieve the node that was dragged.
TreeNode draggedNode = e.Data.GetData(typeof(TreeNode));
// Sanity check
if (draggedNode == null)
{
return;
}
// Retrieve the node at the drop location.
TreeNode targetNode = treeView1.GetNodeAt(targetPoint);
// Did the user drop the node
if (targetNode == null)
{
draggedNode.Remove();
treeView1.Nodes.Add(draggedNode);
draggedNode.Expand();
}
else
{
TreeNode parentNode = targetNode;
// Confirm that the node at the drop location is not
// the dragged node and that target node isn't null
// (for example if you drag outside the control)
if (!draggedNode.Equals(targetNode) && targetNode != null)
{
bool canDrop = true;
while (canDrop && (parentNode != null))
{
canDrop = !Object.ReferenceEquals(draggedNode, parentNode);
parentNode = parentNode.Parent;
}
if (canDrop)
{
// Have to remove nodes before you can move them.
draggedNode.Remove();
// Is the user holding down shift?
if (e.KeyState == 4)
{
// Is the targets parent node null?
if (targetNode.Parent == null)
{
// The target node has no parent. That means
// the target node is at the root level. We'll
// insert the node at the root level below the
// target node.
treeView1.Nodes.Insert(targetNode.Index + 1, draggedNode);
}
else
{
// The target node has a valid parent so we'll
// drop the node into it's index.
targetNode.Parent.Nodes.Insert(targetNode.Index + 1, draggedNode);
}
}
else
{
targetNode.Nodes.Add(draggedNode);
}
targetNode.Expand();
}
}
}
// Optional: The following lines are an example of how you might
// provide a better experience by highlighting and displaying the
// content of the dropped node.
// treeView1.SelectedNode = draggedNode;
// NavigateToNodeContent(draggedNode.Tag);
}