Hi,

  on the Winform Demo application, go to the TreeView demos, and selection "Selection".
1) select the "Folders" item listed under the "Inbox" item.

2) Collapse the "Inbox" item by clicking the ARROW next to the "Inbox"

3) Hold down the SHIFT key and left-mouse click on the "Outbox" item, you end up with a selection all the way up the tree to the ROOT element

How to reproduce:

    DataTable table = new DataTable();
    table.Columns.Add("ParentId", typeof(int));
    table.Columns.Add("ChildId", typeof(int));
    table.Columns.Add("ProductId", typeof(int));
    table.Columns.Add("ProductCode", typeof(string));

    table.Rows.Add(0, 1, 3, "Pr - 01");
    table.Rows.Add(1, 2, 4, "P r- 02");
    table.Rows.Add(1, 3, 5, "Pr - 03");

    this.radTreeView1.DisplayMember = "ProductCode";
    this.radTreeView1.ParentMember = "ParentId"; 
    this.radTreeView1.ChildMember = "ChildId"; 
    this.radTreeView1.ValueMember = "ProductId";
    this.radTreeView1.DataSource = table;

Greetings,

While testing the exporting feature of RadTreeView, I noticed the following issue :

Using the code below , everything works just fine :

But, the following line of the code raises an error in a specific circumasntance (I describe it more, further in the thread)   :

Error Screenshot is attached : 1.jpg

Details about the error :

The Specific Circumstance :

In my RadTreeView's NodeMouseClick , I add some child nodes to the node which is clicked, at runtime :

Then I found out that setting "exporter.ExportChildNodesGrouped" to True causes the error. But if it is set to false, no error raised even in the above Circumstance.

P.S  Normally setting "exporter.ExportChildNodesGrouped" to True or False doesn't cause any error, but adding some child nodes at run time surly does.

Thanks for your attention.

Please refer to the attached sample project. Run the application on a WIndows 10 machine. Switch on the Narrator and try to expand a node then the EnableRadAccessibilityObjects  property is set to true.

Workaround: set the EnableRadAccessibilityObjects property to false.

I've got a tree with multiple nodes like

document1

 -page 1 

  -page 2

document1

 -page 1 

  -page 2

  -page 3

...

document10

 -page 1 

  -page 2

Due to the size of the treeview, only 2 or 3 documents are on screen, the rest is scrolled. (manually added items, no dynamic or lazy loading)

Lets say I click page 2 of document one, hold the mouse button to select more and go down to the last document (the tree is automatically scrolled down, as expected)

But when I go back to review what I selected, only the last items on screen are selected (documents 9 and 10 for example).

When I try to do the same selection with the arrow keys and the shift key, it works fine, but not with the mouse.

Hello,

I use radbreadcrumb as a group path explorer in my software. 

I associate it with a treeview. Please see the attache photos.

When I select a treeviewitem which has too much parent levels, the radbreadcrumb can not display the path completely.

I've tried autoscrollmargin and autoscrollminsize. No luck. Because my radbreadcrumb is in a splitcontainerpanel, the display size is changeable.

I expect a custom function can act like Windows Explorer (see the last attach photo). When there is no enough display space, only the last levels are shown.

PS. I've integrated the telerik solution from this post. And it works great. 

https://www.telerik.com/forums/getting-breadcrumb-to-act-like-windows-explorer-breadcrumb

Thank you by advance.

Kun

Hi all,

RadTreeView is very nice control , For treeline we can give line style, color but we can't set line thickness,

I want to change thickness of Treeline can you guide me how to do it?

Hi there 

I found this issue in RadTreeView filtering

I have a 2-level text structure programmatically created

after creation I use the command

radtree.ExpandAll()

This is the only event handled

Private Sub txtFilter_TextChanged(sender As Object, e As EventArgs) Handles txtFilter.TextChanged

        radtreeNavigazione.Filter = txtFilter.Text

End Sub

When I set a filter with at least 4 letters and then I select the text in the filter box and press "back", the app freezes with cpu working at 50 %. 

I use this workaround to solve

Private Sub txtFilter_TextChanged(sender As Object, e As EventArgs) Handles txtFilter.TextChanged

        radtreeNavigazione.Filter = txtFilter.Text

End Sub

I use this workaround

Private Sub txtFilter_TextChanged(sender As Object, e As EventArgs) Handles txtFilter.TextChanged

      radtree.CollapseAll()       

      radtreeNavigazione.Filter = txtFilter.Text

      radtree.ExpandAll()

End Sub

In this way it works, but I wanted to report the issue.

Thank you in advance for your attention

Afternoon

We have a RadTReeView that we drag nodes around to reorder within the same treeview.

There are about 2000 nodes in the tree that is a self referencing data bound and goes about 15 levels deep at some parts of the tree

When we click left mouse down (keeping it down) to drag and drop reorder a node, using the mouse wheel to scroll the tree up or down does not work anymore

We want to for instance drag a node from a location to another location outside the current view, using the mouse wheel to navigate the tree view up and down. This used to work, but not after upgrading to the new 2019 telerik.

Is there a tree view control option that needs to be toggled for this to work?

Thank you

Theo

To reproduce:
- Open the Property builder, add some nodes and disable them.
- There is no way to enable them at design time. 

Workaround. 
Disable the nodes at runtime.

At the moment the filter predicate is called only for the root nodes. A possible workaround is to recursively apply the filter logic for the child nodes as well.
Workaround:
private void Button1_Click(object sender, EventArgs e)
{
    this.radTreeView1.TreeViewElement.FilterPredicate = this.FilterNode;
    this.radTreeView1.Filter = "Custom";
}

private bool FilterNode(RadTreeNode node)
{
    Console.WriteLine(node.Text);
    if (node.Text.Contains("Child: 3"))
    {
        return true;
    }

    Stack<RadTreeNode> children = new Stack<RadTreeNode>();
    if (node.Nodes.Count > 0)
    {
        children.Push(node);
        while (children.Count > 0)
        {
            RadTreeNode current = children.Pop();
            foreach (RadTreeNode child in current.Nodes)
            {
                if (child.Text.Contains("Child: 3"))
                {
                    return true;
                }

                children.Push(child);
            }
        }
    }

    return false;
}

Hi there, through out our app we use the treeview everywhere - but we have had this issue where it crashes when someone right clicks on the treeview where there is no node. This crash happens on the "ContextMenuOpening" event when we try to use e.TreeElement. This is because, on the telerik side of things, the getter for that property is throwing a NullReferenceException (see attached screenshot)

I think this is happening because in your RadTreeViewCancelEventArgs.cs it is this:

        public RadTreeViewElement TreeElement
        {
            get { return node.TreeViewElement; }
        }

        public RadTreeView TreeView
        {
            get { return node.TreeView; }
        }

But since node == null, it throws the exception. It probably should check for null, and if node is null, return a null for those properties - so we can use null conditional operator to check stuff. We have a workaround but it is just lots of copy and paste of things.

How to reproduce: 

   public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

       
        private void Form1_Load(object sender, EventArgs e)
        {

            radTreeView1.CheckBoxes = true;
            radTreeView1.TriStateMode = true;

            var rootNode = new RadTreeNode("Root Node");
            
            radTreeView1.Nodes.Add(rootNode);

            // Create two parent nodes
            var parentNode1 = new RadTreeNode("First Parent");
            var parentNode2 = new RadTreeNode("Second Parent");

            // Add the parent nodes to tree view's nodes collection
            rootNode.Nodes.AddRange(parentNode1, parentNode2);
            
            
            // Create a child node
            var radTreeNodes2 = new List<RadTreeNode>
            {
                new RadTreeNode("nA.1"),
                new RadTreeNode("nB.2"),
                new RadTreeNode("nC.3"),
                new RadTreeNode("nD.4"),
                new RadTreeNode("nE.5"),
            };
            
            var radTreeNodes = new List<RadTreeNode>
            {
                new RadTreeNode("nA.1"),
                new RadTreeNode("nB.2"),
                new RadTreeNode("nC.3"),
                new RadTreeNode("nD.4"),
                new RadTreeNode("nE.5"),
            };
            
            // Add the child node to the first parent's nodes collection
            parentNode1.Nodes.AddRange(radTreeNodes);
           
            // Remove the child from the first parent collection and add it to the second parent nodes collection
            //parentNode1.Nodes.Remove(childNode);
            parentNode2.Nodes.AddRange(radTreeNodes2);
            rootNode.ExpandAll();
            rootNode.Checked = true;

        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            radTreeView1.Filter = textBox1.Text;

            if(radTreeView1.TopNode != null)
                radTreeView1.TopNode.ExpandAll();
        }
    }

To reproduce:

Run the attached application. Drag Node 2 to after Node 4 while holding down the Alt key. Note that the Node 2 copy is inserted before Node 4.

When Node 2 is dragged to after Node 4 without holding down the Alt key, Node 2 is correctly moved to after Node 4.

Workaround: you can modify the TreeViewDragDropService and control at what position exactly to be inserted the dragged node:

https://docs.telerik.com/devtools/winforms/treeview/drag-and-drop/modify-the-dragdropservice-behavior
https://docs.telerik.com/devtools/winforms/treeview/drag-and-drop/drag-and-drop-in-bound-mode

To reproduce: use the following code snippet. You will notice that mnemonics are displayed.

        public RadForm1()
        {
            InitializeComponent();
            new RadControlSpyForm().Show();

            this.radTreeView1.DisplayMember = "name";
            this.radTreeView1.ParentMember = "pid";
            this.radTreeView1.ChildMember = "id";
            this.radTreeView1.DataSource = this.GetSampleData();
           
            this.radTreeView1.NodeFormatting += radTreeView1_NodeFormatting;
            this.radTreeView1.SelectedNodeChanged += radTreeView1_SelectedNodeChanged;
            
            this.radBreadCrumb1.DefaultTreeView = this.radTreeView1;
        }

        private void radTreeView1_SelectedNodeChanged(object sender, Telerik.WinControls.UI.RadTreeViewEventArgs e)
        {
            foreach (RadSplitButtonElement item in this.radBreadCrumb1.BreadCrumbElement.Items)
            {
                item.ActionButton.TextElement.UseMnemonic = false;
            }
        }
         
        private void radTreeView1_NodeFormatting(object sender, Telerik.WinControls.UI.TreeNodeFormattingEventArgs e)
        {
            e.NodeElement.ContentElement.UseMnemonic = false; 
        }

        private DataTable GetSampleData()
        {
            DataTable dt = new DataTable();

            DataColumn dc = new DataColumn();
            dc.ColumnName = "id";
            dc.DataType = typeof(int);
            dt.Columns.Add(dc);

            DataColumn dc1 = new DataColumn();
            dc1.ColumnName = "name";
            dc1.DataType = typeof(string);
            dt.Columns.Add(dc1);

            DataColumn dc2 = new DataColumn();
            dc2.ColumnName = "pid";
            dc2.DataType = typeof(int);
            dt.Columns.Add(dc2);

            DataRow dr = dt.NewRow();
            dr[0] = 0;
            dr[1] = "Hello & Goodbye";
            dr[2] = DBNull.Value;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 1;
            dr[1] = @"&C:\";
            dr[2] = 0;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 2;
            dr[1] = @"&D:\";
            dr[2] = 0;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 3;
            dr[1] = "&Program Files";
            dr[2] = 1;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 4;
            dr[1] = "M&icrosoft";
            dr[2] = 3;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 5;
            dr[1] = "&Telerik";
            dr[2] = 3;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 6;
            dr[1] = "&WINDOWS";
            dr[2] = 1;
            dt.Rows.Add(dr);

            return dt;
        }

Workaround: set the DefaultTreeView before subscribing to the treeview events.

            this.radBreadCrumb1.DefaultTreeView = this.radTreeView1;
            this.radTreeView1.NodeFormatting += radTreeView1_NodeFormatting;
            this.radTreeView1.SelectedNodeChanged += radTreeView1_SelectedNodeChanged;

To reproduce:

        public RadForm1()
        {
            InitializeComponent();

            BindingList<Item> items = new BindingList<Item>();
            items.Add(new Item(0,"Root", CheckState.Checked,-1));
            for (int i = 1; i < 5; i++)
            {
                items.Add(new Item(i, "Node" + i, CheckState.Checked,0));
            }
          
            this.radTreeView1.CheckBoxes = true;
            this.radTreeView1.DisplayMember = "Name";
            this.radTreeView1.ChildMember = "Id";
            this.radTreeView1.ParentMember = "ParentId";
            this.radTreeView1.CheckedMember = "IsActive";
            this.radTreeView1.AutoCheckChildNodes = true;
            this.radTreeView1.TriStateMode = true;
            this.radTreeView1.DataSource = items;
            this.radTreeView1.ExpandAll();
        }

        public class Item
        {
            public int Id { get; set; }

            public string Name { get; set; }

            public CheckState IsActive { get; set; }

            public int ParentId { get; set; }

            public Item(int id, string name, CheckState isActive, int parentId)
            {
                this.Id = id;
                this.Name = name;
                this.IsActive = isActive;
                this.ParentId = parentId;
            }
        }

Workaround: implement a TypeConverter that can handle converting from/to System.Windows.Forms.CheckState. A sample implementation for creating a custom TypeConverter is demonstrated in the following help article: https://docs.telerik.com/devtools/winforms/treeview/data-binding/togglestateconverter

To reproduce: please run the attached sample project and follow the steps in the attached sample gif file.

Workaround: instead of filtering the nodes, you can manipulate the RadTreeNode.Visible property considering the filter criteria and whether the node contains a child that matches the filter. 
        public RadForm1()
        {
            InitializeComponent();

            this.radTreeView1.ShowLines = true; 
        }

        private void FilterNode(RadTreeNode node)
        {
            bool atLeastOneChildMatches = false;
            ChildNodeContains(this.radTextBox1.Text.ToLower(), node.Nodes, ref atLeastOneChildMatches);
            if (node.Text.ToLower().Contains(this.radTextBox1.Text.ToLower()) || atLeastOneChildMatches)
            {
                node.Visible = true;
            }
            else
            {
                node.Visible = false;
            }
        }

        private void ChildNodeContains(string filterCritria, RadTreeNodeCollection nodes, ref bool atLeastOneChildMatches)
        {
            foreach (RadTreeNode node in nodes)
            {
                if (node.Text.ToLower().Contains(filterCritria))
                {
                    atLeastOneChildMatches = true;
                    return;
                }
                if (atLeastOneChildMatches == false && node.Nodes.Count > 0)
                {
                    ChildNodeContains(filterCritria, node.Nodes, ref atLeastOneChildMatches);
                }
            }
        }

        private void radTextBox1_TextChanged(object sender, EventArgs e)
        {
            PerformFilter(this.radTreeView1.Nodes);
        }

        private void PerformFilter(RadTreeNodeCollection nodes)
        {
            foreach (RadTreeNode node in nodes)
            {
                FilterNode(node);
                if (node.Nodes.Count > 0)
                {
                    PerformFilter(node.Nodes);
                }
            }
        }

To reproduce.
- Add 100 nodes so the scroll appears. 
- Try scrolling to bottom.

Workaround:
radTreeView1.TreeViewElement.Scroller.ScrollMode = ItemScrollerScrollModes.Discrete;