Last Updated: 29 May 2020 14:06 by Matt


I have an issue/query if you wouldn't mind help me out with please.

When using multiple monitors, if the main monitor is on scale and layout 100% and the 2nd monitor is 150%. When showing the context menu it blows the menu up even when shown on the main screen (see attached images).

Is there any way to disable Scale and Layout affecting the scale of the context menu or for the context menu to determine which screen it's being displayed on and use the Scale and Layout for that monitor?


Last Updated: 29 May 2020 12:25 by ADMIN


please see the attached sample and screen shot.

If application with Ribbon Bar is moved to a high dpi display (or started on a 4K display), two issues happen:

  1. The title bar is not scaled (font) and has an ugly black line
  2. The drop down element font is not scaled (the list itself is correct)


Last Updated: 29 May 2020 05:45 by ADMIN

I created a simple project just with a dropdownlist. The data source of the dropdownlist is a reader from SQL. First time, when I type something in the text area of the dropdownlist, the autocomplete works perfectly: if a type "235", it brings me at the first job starting with '235' and I can select the job. After, when I click back in the text area to type something else (for example: "236"), I can just type '2'. It won't let me type anything else and the autocomplete is not working. The autocomplete mode is Suggest.

This is a new problem with telerik 2020.2.512.40. Just previously, I had the trial version (2020.1.218.40) and it was working without problem. I didn't change anything in the small project. In fact, I took this project and put Telerik.Wincontrols.UI version 2020.1.218.40 anf it was working properly. I put back the version 2020.2.512.40 of the control and the problem reappeared.


First time (works fine):


Seconf time: not able to type more than 1 character


In Development
Last Updated: 28 May 2020 11:39 by ADMIN

When RadGridView is bound to a collection of 60 000 records the difference in the sorting time between using a ProBindingSource and a DataTable is massive. Changes in any core logic in both internal implementations, RadGridView and ProBindingSource, isn't so easy as it looks. Both products have been for a very long time on the market designed to cover the main scenarios of the target customers groups for which they are developed.

By default, if the rows count is less than 10 000 we use quick sort to order the items in the grid. If there are more items we use Red-Black tree. This is controlled by the UseHybridIndex property.  

(radGridView.MasterTemplate.ListSource.CollectionView as GridDataView).UseHybridIndex = false;

However, both of algorithms use non-linear data access. If the ProBindingSource is not optimized to get data not linearly, the performance wouldn't be satisfactory. 

That is why we have introduced the BypassSort functionality to cover this case after cooperation with the OE developers. Thus, our RadGridView won't perform any logic for sorting and the whole time necessary for sorting will depend on the DataSource itself (ProBindingSource in your case) and how this collection sorts its items: https://docs.telerik.com/devtools/winforms/controls/gridview/sorting/basic-sorting 

In the current version of Telerik UI for WinForms suite, the BypassSort property is ignored if the BypassFilter is not set to true as well. Hence, the sorting will be still slow.

Both properties shouldn't affect each other and if a developer wants to improve only the sorting performance, it is expected to enable only the ByPassSort property.


Last Updated: 28 May 2020 10:06 by n/a
Now, I have 2 problems:

1. Checking / Unchecking header check box, checks/unchecks checkboxes of current page only.  I need to perform the operation for the whole grid.

2. I have got filters on.  User can select filters on columns.  Once filters are applied, records are displayed according to those filters (other records are hidden).  Now, when checking the header check box, it only selects records that are part of current page.  For example, if I am on first page and apply filter on one column, grid will hide all rows from the first page that do not match the filter and pull records from 2nd and 3rd pages that match the criteria and show on the first page.  But if I select check box in the header, then only records from first page are selected, records that came from 2nd and 3rd page are not selected.

In Development
Last Updated: 27 May 2020 15:57 by ADMIN

Dear Support,

I want to use the new feature - Support for SVG.

Then I have to load the file with RadSvgImage.FromFile().

I get the following exception:

System.Xml.XmlException: 'External DTD subset cannot be resolved - public ID =' - // W3C // DTD SVG 1.1 // EN ', system ID =' http://www.w3.org/Graphics/ SVG / 1.1 / DTD / svg11.dtd '.'

(Translated from German)

Problem is line 2, where the DTD is given.

Is there a way to tell XmlSerializer to ignore the validation?

Last Updated: 26 May 2020 09:09 by ADMIN

Please run the sample project on 100% and 150% DPI scaling. You will notice that with 100% the shown form is centered to its parent, but with 150% it is shifted:

Last Updated: 26 May 2020 07:56 by ADMIN

To reproduce: 

Add the rule from this article and observe the result: Data Validation

Last Updated: 26 May 2020 06:35 by ADMIN

Please use the following code snippet and click the filter button for the first column in the virtual grid. You will notice that the default menu is shown:

        RadContextMenu menu = new RadContextMenu();
        public RadForm1()
            RadDateTimePicker aDateTimePicker = new RadDateTimePicker();
            RadMenuItem theMenuItem = new RadMenuItem();
            theMenuItem.MinSize = new Size(200, 30);
            RadHostItem theHostItem = new RadHostItem(aDateTimePicker);
            this.radVirtualGrid1.RowCount = 50;
            this.radVirtualGrid1.ColumnCount = 5;

            this.radVirtualGrid1.AllowFiltering = true;

        private void radVirtualGrid1_ContextMenuOpening(object sender, VirtualGridContextMenuOpeningEventArgs e)
            int i;
            string theMenuItemText;

            if (e.RowIndex == -3 && e.ColumnIndex < 1)
                e.ContextMenu = menu.DropDown; 

        private void radVirtualGrid1_CellValueNeeded(object sender, VirtualGridCellValueNeededEventArgs e)
            e.Value = Guid.NewGuid().ToString();

Last Updated: 25 May 2020 04:41 by ADMIN

An error occur when i used .Import method on large .pdf files (> 1000 ko) with an Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.PdfFormatProvider object.


Message is:

"Impossible d'effectuer un cast d'un objet de type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.PdfDictionary' en type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.PdfInt'." 

There is no bug for smaller pdf files. 


Thank you 

Last Updated: 21 May 2020 10:07 by ADMIN
Please use the following code snippet and try to resize the button as it is illustrated in the attached gif file: 
            this.radButton1.ButtonElement.ImagePrimitive.SvgImage = RadSvgImage.FromFile(@"..\..\image.svg");
            this.radButton1.TextImageRelation = TextImageRelation.TextBeforeImage;
            this.radButton1.ButtonElement.ImagePrimitive.ImageLayout = ImageLayout.Zoom; 
            this.radButton1.ButtonElement.ImagePrimitive.StretchVertically = true;
            this.radButton1.ButtonElement.ImagePrimitive.StretchHorizontally = true;
Last Updated: 21 May 2020 07:48 by ADMIN


I am working on making our Winforms UI projects DPI aware to clean up fuzzy text in Windows 10.

I'm having an odd issue with some layouts. In one example, we have a simple form dialog that will grow with a label inside (similar to a windows message box). THe label is autosizing itself and has a minimum and maximum size set. This dialog is working fine without the DPI awareness, however, after enabling, the RadForm resizes to some strange size. I tried to investigate and it seems that the label is resizing to some large size and not respecting it's maximums (though this doesn't show when rendering as I've switched off the borders).

The label is resizing the form via anchors. I think probably there is a better way at layout here, but I'm wondering if the wild resizing may be considered a bug.

See images below.

I've also attached a project that reproduces this issue.



Last Updated: 19 May 2020 05:19 by Suresh G


In RadCheckedDropDownList, We are using 'TelerikMetroBlue' theme. When we select multiple items in dropdownlist, its creating issue in rendering items in TextBlock. Selected items are coming on top of DropDownListElement ArrowButton, I can't see arrow button clearly due to items in background. If i use another theme then its working fine but i have to use 'TelerikMetroBlue' theme. please find attached.


Please advise.

Last Updated: 15 May 2020 13:33 by ADMIN


Using the spellchecker, and the popup when using themes overlaps as per image below. If i make : 

        e.SpellingForm.Controls("buttonIgnoreAll").Visible = False
The next one below does the same. How do i modify this ? 






Last Updated: 15 May 2020 13:31 by ADMIN


I have menu problem:

When the Backstage Button Item is clicked and you don't release a left mouse button click but instead mouse is dragged to the right of the form, Backstage Button Item stay selected and can only be returned to default state if you click on it again else its stays blue and locked.

Picture 1.

Left click, hold and drag to the right. This state can be done to all buttons see Picture 2. Focus on "MouseDown" Event is not working.

Picture 2.


My question is can this behavior be prevented ?


Thanks in advance !



Last Updated: 15 May 2020 13:26 by ADMIN
Release Q2 2016 SP1
Merge all assemblies exept Telerik.WinControls.UI.Design.dll.
Use the merged assembly in an application with RichTextEditorRibbonBar.
The icons are missing. 
Last Updated: 15 May 2020 13:22 by ADMIN

merging only these assembly still the icons are not visible in Spreadsheet ribbon menu

C:\Program Files (x86)\Microsoft\ILMerge\ILMerge.exe" /allowdup /target:SymphonyMESUtil.exe  /targetplatform:"v4, C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.6.1" /out:Merge\SymphonyMESUtil.exe ^
SymphonyMESUtil.exe ^
Telerik.WinControls.dll ^
Telerik.WinControls.UI.dll ^
TelerikCommon.dll ^
Telerik.WinControls.GridView.dll ^
Telerik.Windows.Documents.Spreadsheet.FormatProviders.OpenXml.dll ^
Telerik.Windows.Documents.Spreadsheet.FormatProviders.Pdf.dll ^
Telerik.Windows.Documents.Spreadsheet.dll ^
Telerik.WinControls.RadSpreadsheet.dll ^
Telerik.Windows.Documents.Core.dll ^

Last Updated: 14 May 2020 10:27 by ADMIN
Hi Guys,

I'm crashing an app with TreeViewControl when open dialog is shown and you double click on file in that dialog and file current location is above treeview nodes.

Added example and animated gif so you can also try.


************** Exception Text **************
System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.WinControls.UI.RadTreeViewElement.FindSelectionStartAndEndNodes(RadTreeNode nodeUnderMouse, RadTreeNode& fromNode, RadTreeNode& toNode)
   at Telerik.WinControls.UI.RadTreeViewElement.ProcessMouseSelection(Point location)
   at Telerik.WinControls.UI.RadTreeViewElement.ProcessMouseMove(MouseEventArgs e)
   at Telerik.WinControls.UI.RadTreeView.OnMouseMove(MouseEventArgs e)
   at System.Windows.Forms.Control.WmMouseMove(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at Telerik.WinControls.RadControl.WndProc(Message& m)
   at Telerik.WinControls.UI.RadTreeView.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


Best regards

Last Updated: 14 May 2020 05:50 by ADMIN
Created by: Ketan
Comments: 2
Category: GridView
Type: Bug Report


Please check the attached sample project.

I think CompositeFilter does not respect CaseSensitive property.


Last Updated: 13 May 2020 11:58 by ADMIN
Created by: Peter
Comments: 1
Category: FileDialogs
Type: Bug Report

I use the RadOpenFileDialog with the MultiSelect property set to True. My test folder contains 105 files with sizes about 1 to 2 kb and all the same extension.  If I select multiple files with <ctrl>+<mouse left> the selection behaves as expected. If I select multiple files with <shift>+<mouse left> I have to wait al long time. Unselecting the file by clicking on an unselected entry is also very slow.  If I try to select all files with <ctrl>+<A> the dialog remains busy and does not respond anymore. 

My code for testing is as simple as this:

        private static void TestFileOpenDialog()
            RadOpenFileDialog dlg = new RadOpenFileDialog();
            dlg.InitialDirectory = @"path to files"; // 105 files with sizes from 1 to 2 kb
            dlg.Filter = "my files (*.mal)|.mal";
            dlg.FilterIndex = 0;
            dlg.MultiSelect = true;
            DialogResult result = dlg.ShowDialog();


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