Need More Info
Last Updated: 31 Jul 2023 16:13 by ADMIN
Created by: erwin
Comments: 3
Category: UI for WinForms
Type: Feature Request
It would be nice if the grid column chooser would support grouping of columns similar to the jquery grid
Need More Info
Last Updated: 07 Apr 2023 14:04 by ADMIN
Created by: James
Comments: 1
Category: UI for WinForms
Type: Bug Report

Zooming in will throw an Exception that crashes the program.

The ZoomLevel needed to cause the exception is dependent on the area of the RadMap selected.

Provider: BingRestMapProvider

ImagerySet AerialWithLabelsOnDemand



Zooming in over Antarctica, Exception thrown zooming in at MapElement.ZoomLevel 14.


Zooming in over Australia, Exception thrown zooming in at MapElement.ZoomLevel 21.


Need More Info
Last Updated: 31 Mar 2023 09:59 by ADMIN
This event works for FilterViewTextCategoryElement, but not for FilterViewBooleanCategoryElement.
Private Sub Filter_CategoryCreating(sender As Object, e As FilterViewCategoryCreatingEventArgs)
   AddHandler DirectCast(e.Category, FilterViewBooleanCategoryElement).ItemCreated, AddressOf BoolCategoryItemCreated
Need More Info
Last Updated: 27 Mar 2023 12:48 by ADMIN


  1. Create a RadTreeView
  2. Set the TreeViewElement.ExpandTimerInterval to 5 seconds.
  3. Enable drag/drop.
  4. Fill the tree with random nodes and childnodes
  5. Drag a node over other nodes. Make sure you do not hover longer than 5 seconds over a single node. So just move around.

Observed behavior:

  1. After 5 seconds the node you are just hovering over, is expanding.

Expected behavior:

  1. No node will automatically expand. Every time a new node is hovered over, the timer will reset.

Need More Info
Last Updated: 13 Jan 2023 11:31 by ADMIN
Created by: kieran
Comments: 1
Category: TimePicker
Type: Bug Report

Hi there.

Selecting a time from the TimePicker sets the time.  However, if the bound parameter is null, the Date part of the DateTime values are still invalid and will throw errors when saving data to databases.

The TimePicker should at least by default insert a default valid Date even if it is 01/01/1900 or DateTime.Today.

Regards Kieran.


Need More Info
Last Updated: 30 Nov 2022 05:59 by ADMIN

I can't provide a project or even code snippets that would make sense out of context because the code base is too complex for an easy replication to be setup.

We are trying various things like calling Refresh, Update.


Hoping this is something you've encountered before and have some suggestions.

Need More Info
Last Updated: 22 Sep 2022 06:06 by ADMIN

C#. net core 6, winforms application, TekerikNuGet3 package source, UI.for.WinForms.AllControls.NetCore package 2022.2.622

I am trying to export selected cells from a RadGridView as a csv file.

When using "var exporter = new ExportToCSV(Dgv)" then "exporter.RunExport(fileName);" writes the csv file correctly. It exports every cell.

It doesn't support exporting selections so I wrote a function to do this . The one below is what I used in my project to test what I was doing. It initially writes the csv to a worksheet and wrote that using formatprovider to file, then I just created a stringbuilder adding quotes and appended that to the file afterwards.

Writing the worksheet, the csv values haven't been quoted, plus number fields have had leading zeros removed which proves to be a problem when telephone numbers are stored in a field.

So I googled and found the Settings property which is there to set csv options. But they are private, not public therefore I can't set up the csv propertly.

private void radButton1_Click(object sender, EventArgs e)

    var workbook = new Workbook();
    var worksheet = workbook.Worksheets.Add();

    var rowIndex = 0;
    var columnIndex = -1;
    var sb = new StringBuilder();
    var prevColumnIndex = -1;

    // ForEach cell are accessed vertically then horizontally.
    foreach (var cell in Dgv.SelectedCells)
      // Cell is included in selection even if it's invisible
      // so check visibility and ignore if it isnt
      if (!cell.ColumnInfo.IsVisible) continue;

      // At bottom of column, rownum will change. Watch for this
      // and reset x and y values
      var rowNum = cell.RowInfo.Index;
      if (rowNum != prevColumnIndex)
        prevColumnIndex = rowNum;
        rowIndex = 0;
      else if (!string.IsNullOrEmpty(sb.ToString()))

      var value = cell.Value;
      worksheet.Cells[columnIndex, rowIndex++ ].SetValue(value.ToString());

    var fileName = @"C:\temp\SampleFile.csv";

    IWorkbookFormatProvider formatProvider = new CsvFormatProvider();
    using var output = new FileStream(fileName, FileMode.Create);
    formatProvider.Export(workbook, output);

    // Write contents of sb to the file for comparison sake
    File.AppendAllText(fileName, sb.ToString());


Need More Info
Last Updated: 03 Aug 2022 12:11 by ADMIN

I just upgraded to the latest version of Telerik products and facing the issues described below.

When dragging and drop Telerik UI objects from the toolbar on a form, the dialog box below is displayed with question but there is no button to click to answer the question and I don't where to stop it.

See screenshot attached.

Need More Info
Last Updated: 10 Mar 2022 08:52 by ADMIN
Created by: Ian
Comments: 1
Category: UI for WinForms
Type: Feature Request

GridView has a default text alignment for new columns as 'MiddleCenter'.

Default alignment for new GridViewDataRowInfo is 'left'.

Please can these be the same ?

Need More Info
Last Updated: 18 Feb 2022 08:53 by ADMIN
Created by: MrBizzl
Comments: 7
Category: Installer and VS Extensions
Type: Bug Report

Dear Ladies and Gentlemen

Currently I am trying in vain to upgrade to the latest version Telerik UI for WinForms 2022.1.118.
However, the update fails with the error given below.

I have already uninstalled and reinstalled VS2019. Unfortunately this did not help.

Can you help?

Best Timo

Need More Info
Last Updated: 15 Feb 2022 14:48 by ADMIN
Created by: Ian
Comments: 1
Category: ChartView
Type: Feature Request
Some other charting frameworks support ‘dynamic’ graphs/diagrams, where the graph shows nodes and links, and the user can drag the nodes around the page, and the other nodes are pulled around it. This is a great way to visualise and explore this kind of node+link data. Its also a great way to sell and app, as it looks cool.
Need More Info
Last Updated: 28 Jan 2022 09:03 by ADMIN
Created by: Haithem
Comments: 1
Category: PdfViewer
Type: Bug Report



I am have a problem with pdf wiewer when the PDF file contains an images , it is slow in movement and it is difficult to navigate between pages. Is it possible to fix this problem 



Need More Info
Last Updated: 02 Dec 2020 14:48 by ADMIN

Hi All,

Note:- I am using Bound RadTreeview. Bound with DataSource.

1 Take RadTreeview

2 Add Few nodes Like:

    ......Node A

    ......Node B

    ......Node C

    ............Node D

    ............Node E

3 Now Drag Node B and Drop it in Node C (As Node C's Child)

4 It throw Exception Error Msg  "Collection was modified; enumeration operation may not execute."

5  Now Try to Drag Node E and Drop it in Node B, again same error occurs

6 Full error screen i attached here.

Please reply as soon as possible.


Need More Info
Last Updated: 02 Dec 2020 14:37 by ADMIN
Created by: avani
Comments: 1
Category: TreeView
Type: Bug Report

Hi All,


I have made User control for custom node, in this user control i have used following controls

1 RadLabel (no of control - 3)

2 RadPanel (no of control -1)

3 PictureBox (no of Control - 4 )

4 TableLayoutPanel (no of control -3)

Means i have used total 11 controls within my user control.

Height of usercontrol = 146

Width of Usercontrol = 595


I have taken RadTreeView and above UserControl added as Node,following properties of treeview is set

this.radTreeView1.DataSource = Staff.GetStaff();
            this.radTreeView1.ParentMember = "ParentID";
            this.radTreeView1.ChildMember = "ID";
            this.radTreeView1.DisplayMember = "Department";
            this.radTreeView1.CreateNodeElement += this.OnCreateNodeElement;

this.radTreeView1.TreeViewElement.AutoSizeItems = true;
            this.radTreeView1.ShowRootLines = false;
            this.radTreeView1.FullRowSelect = false;
            this.radTreeView1.ShowLines = true;
            this.radTreeView1.LineStyle = TreeLineStyle.Solid;
            this.radTreeView1.LineColor = Color.FromArgb(110, 153, 210);
            this.radTreeView1.TreeIndent = 50;



But when i run the code it shows like this means my control is not displaying and the property "AutoSizeItems" is not working.


hope for quick reply

Need More Info
Last Updated: 02 Dec 2020 14:36 by ADMIN

Hello Guys,


Good Evening , As per your suggestions i make my custom treeview node with LiteVisualElements .

In That Node i have taken one StackLayoutElement and RoundRectShape assigned to it but still panel shows corners instead of round edges,

i tried with different properties and styles but not get succeed , so please help me out.

here i have attached image of my node and "stackLayoutElement" code too.

spnlControls = new StackLayoutElement();
            spnlControls.Orientation = Orientation.Horizontal;
            spnlControls.NotifyParentOnMouseInput = true;
            spnlControls.DrawFill = true;
            spnlControls.DrawBorder = true;
            spnlControls.Shape = new RoundRectShape(4);
            spnlControls.BackColor = Color.Transparent;
            spnlControls.BackColor2 = Color.Transparent;
            spnlControls.BackColor3 = Color.Transparent;
            spnlControls.BackColor4 = Color.Transparent;
            spnlControls.BorderGradientStyle = GradientStyles.Solid;
Need More Info
Last Updated: 02 Dec 2020 14:35 by ADMIN
Created by: Kaan
Comments: 1
Category: UI for WinForms
Type: Feature Request


I want to hide some columns of the table I received from Excel on RadGridView.

Need More Info
Last Updated: 02 Dec 2020 14:34 by ADMIN
Created by: Larry
Comments: 1
Category: RichTextEditor
Type: Bug Report
There appears to be an issue when adding Comments that overlap each other. I will attach a video to my next reply that shows how to replicate the issue.
Need More Info
Last Updated: 02 Dec 2020 14:33 by ADMIN
Fatching data from sql database in gridViewCommboBoxColumn select the value then retrieve data other column in the same Rows windows application in
Need More Info
Last Updated: 30 Nov 2020 14:59 by ADMIN
The filter UI controls in ASP.NET Core and MVC are really nice, see filter. Can you include the same controls and UI be included in Winforms and WPF?
Need More Info
Last Updated: 30 Nov 2020 14:59 by ADMIN
Created by: Mario
Comments: 3
Category: UI for WinForms
Type: Feature Request

Hi everybody


I m try use the class CustomDragandDrop on radtreeview but i have a issue, 

if i use the next example, i dont have any problem:


   protected void BindRadTreeView()
            DataTable dt = new DataTable();
            dt.Columns.Add("Id", typeof(string));
            dt.Columns.Add("Title", typeof(string));
            dt.Columns.Add("ParentId", typeof(string));

            string parentId = string.Empty;
            string childId = string.Empty;
            for (int i = 0; i < 2; i++)
                parentId = Guid.NewGuid().ToString();
                dt.Rows.Add(parentId, "Node" + i, null);
                for (int j = 0; j < 5; j++)
                    childId = Guid.NewGuid().ToString();
                    dt.Rows.Add(childId, "SubNode" + i + "." + j, parentId);

            this.radTreeView1.ChildMember = "Id";
            this.radTreeView1.ParentMember = "ParentId";
            this.radTreeView1.DisplayMember = "Title";
            this.radTreeView1.DataSource = dt;



i can drag and drop correctly


but the problem is when i binding the Radtreeview



    protected void llenatreeview1() {

            dtTablas = dat.consultaBD();

            DataTable dt = new DataTable();
            dtCopi.Columns.Add("Id", typeof(string));
            dtCopi.Columns.Add("Title", typeof(string));
            dtCopi.Columns.Add("ParentId", typeof(string));

            string parentId = string.Empty;
            string Id = string.Empty;
            string title = string.Empty;
            foreach (DataRow row in dtTablas.Rows)
                parentId = row["ParentId"].ToString();     

                Id = row["Id"].ToString();
                title = row["Title"].ToString();

                if (parentId == "")
                    dt.Rows.Add(Id, title, null);
                    dt.Rows.Add(Id, title, parentId);

            radTreeView2.ChildMember = "Id";
            radTreeView2.ParentMember = "ParentId";
            radTreeView2.DisplayMember = "Title";
            radTreeView2.DataSource = dt;

first is freeze and then appears the error.

when i drag and drop appears then next error:



what am I doing wrong please your help. thanks
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