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: 

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 =' 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 12:06 by ADMIN

I have a radGridView with a radContextmenu attached. When I open the radContextmenu via right clicking a form and then move the mouse scroll wheel radContextmenu is closed and the form behind the radContextmenu begins to scrolls. This does not happen with the standard contextMenu. 

I would like to avoid the mouse scroll wheel from closing the radContextmenu. The reason is in some radContextMenus I embed forms with scroll bars and so would like the user to use the mouse wheel to scroll these embedded forms (I can confirm that the scroll bars on these forms work fine while embedded in the context menu) rather than close the radContextmenu.

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 14:02 by ADMIN


In my application, depending on the specific data in the grid I may want to warn a user who clicks on the header checkbox that changing all the values in that column may not be what he intends, allowing him to cancel out of the operation.  I haven't found a handler that gets called when clicking on the header checkbox that allows me to cancel the event.  How can I accomplish this?

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: 18 May 2020 05:47 by ADMIN
Created by: Dimitar
Comments: 0
Category: RichTextEditor
Type: Feature Request
Compare documents functionality similar to MS Word
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: 15 May 2020 09:13 by ADMIN
I'd like to know if it's possible to add Auto-Complete functionality to the Chat UI in WinForms.  I want to be able to tag a user in the chat message.  When I type the '@' symbol I want the auto-complete to start with a prepopulated list of users.
Last Updated: 14 May 2020 11:19 by ADMIN
Created by: n/a
Comments: 1
Category: WebCam
Type: Feature Request



I am using the WebCam Control in WinForms (latest Version) and placed it on an empty form. Then I tested this "program" on a Test device (CAT T20 Win10 Tablet). The preview picture in the control does not match the orientation of the device. (depending on which side of the device is at top the visible picture is rotated 90/180 degrees).

For testing purposes I installed the WinForms Example application on the same tablet device with the same results.

How to sync the captured picture to the orientation of the device? In the WPF documentation of the WebCamControl I found a Videoflip method, which is not available in WinForms.

Best regards,




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

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