Telerik UI for Winforms

Release History

UI for WinForms R3 2021 (version 2021.3.914)

September 15, 2021

New Controls

  • RadTaskBoard - a Kanban-like control that comes with many features, like columns, tasks, users, tags, drag and drop, selection, accent settings, touch support, etc.
  • RadFilterView - a user-friendly UI for building filter descriptors. It builds appropriate categories and editors and provides easy to use UI for filtering large amounts of data.
  • Hierarchy in the Navigation View - the Navigation View inside RadPageView can now build a hierarchy. This mode supports drag and drop, infinite nesting, and comes with various settings controlling the visual appearance.

Support and Compatibility

  • .NET 6.0 - We’ve built our controls against all the preview versions of .NET 6.0 and we can confirm that we are fully compatible.
  • Visual Studio 2022 support - the biggest gain is that the devenv.exe process is 64 bits, and the application should better handle large solutions.
  • WinForms Converter - converts the Microsoft controls to Telerik ones. Now the converter is compatible with the latest official Visual Studio.


  • Sometimes RadMenuComboItem hides before clicking on it.

Converter Tool

  • Form's designer file is missing in the converter wizard if the form's file name ends with "Settings"


  • InitialDirectory not working when DialogType is RadOpenFolderDialog.


  • System.OverflowException when setting CategoricalDataPoint value to decimal.MaxValue/decimal.MinValue.
  • The last symbol in title is cut off when exporting to image.


  • "Is in list" filter operator doesn't work correctly when the values contains intervals.


  • Control's Height doesn't refresh after change font unit at design-time.


  • Setting AutoScroll to true doesn't allow you to scroll the form's container at design time.


  • Add option to set EndEditOnLostFocus property of editors.
  • Exception when colapsing a row that has a RadTextBoxControlEditor open.
  • Layout does not load correctly the FilterDescriptor if filtered by blank.
  • Missing rows when filtering the grid on Infinity values.
  • NullReferenceException when call BestFitColumns method and rebind the grid with custom theme.
  • RadDropDownListEditor has incorrect style for its popup.


  • Add zooming functionality that considers the mouse position.


  • Unhandled exception on Items.Remove.


  • Elements should be hit tested with points lying on the path's outline (border/contour).
  • Hint over Pins in Maps doesn't show hint with accent properly.
  • Layers.HitTest method overloads should all consider whether the layer is visible or not.
  • MapPins are shifted at certain zoom levels when you change the pin's size.
  • Setting left padding to MapCallout is applied to right also.


  • Improve the EMailMaskTextBoxProvider to allow TLDs which are longer than 4 characters.


  • Incorrect popup's position when the AutoSizeDropDownToBestFit property is enabled.


  • Setting in the NavigationView allowing selection of the page view items when there is not enough space and the items container cannot fit the available space.
  • Add hierarchy to the NavigationView.
  • RadPageView: Changing the HeaderHeight property at runtime of the NavigationView does not update the Hamburger button height


  • High DPI Mode doesn't scale.


  • Appointment Mapping dialog is not visible with VS dark theme.
  • Displaying an appointment with a subject of empty html tags <> will crash the program.
  • Date label doesn't respect the DisplayedCellsCount in the active view.


  • Changing Sheet name at Runtime doesn't update name.
  • The document should be scrolled with the MouseWheel.
  • Alert message is showing twice when using Ctrl+V to paste on a protected sheet.
  • Control crashes when right-clicking "Copy" on an empty cell.
  • Double-Clicking the fx button in the formula bar allows modifications to protected worksheet.
  • Scroll bar is not working as expected.
  • Zoom Control skips over increments when clicking arrow(s) quickly.


  • ArgumentOutOfRangeException when running the application and the NumbersColor is set at design time via the Element Hierarchy Editor.


  • Wrong Embedded Label position in TextBox.


  • Incorrect Caret position after user's input when AutoComplete is enabled.
  • New character is not insert at the correct position.


  • After paste opening editor causes text set to 23:59.


  • Appium is unable to locate RadTreeNodes outside of the first parent node collection.


  • Incorrect text rendering when changing the Font.


  • Fixed ComboBox and DropDownList content controls should not change value when list is updated.
  • Introduced support for Non-Breaking Spaces.
  • Minor fixes for the content controls.
  • Performance issue in the latest version after changing the document multiple times.
  • Memory leak in ContentControlsPositionManager with surviving WeakEventHandler instances when loading a new document.
  • А memory leak with surviving SpanProperties instances when loading a new document.
  • Calling a ChangeAllFieldsDisplayMode(FieldDisplayMode.Result) on a document containing a multiline document variable leads to wrongly updated span box text.
  • Ribbon TableStylesGallery event handler memory leak.
  • The watermark position is not correct when using multiline text.
  • FloatingDrawing (shape or image) stays selected when right-clicking somewhere outside it.


  • Handle import of documents containing Simple fonts with names of entries in the Encoding`s Differences that are not part of the Adobe Glyph List.
  • Introduced support for handling documents containing invalid cross-reference table start index.
  • The default radio button state is not displayed correctly with specific documents.
  • Text cannot be selected in FitToPage mode.
  • Text is extracted with wrong characters when there is Simple Font without ToUnicode mapping.
  • NullReferenceException is thrown when annotation has appearance state but uses single state appearances.


  • Handle import of documents containing Simple fonts with names of entries in the Encoding`s Differences that are not part of the Adobe Glyph List.
  • Introduced support for handling documents containing invalid cross-reference table start index.
  • An ArgumentOutOfRangeException is thrown when importing a document containing a specific image stream.
  • Unable to import field with a name that is not specified as a literal string.
  • An exception is thrown when the NormalContentSource of a widget is null and one flattens the form fields.
  • An exception is thrown when importing a file with LabColor gradients.
  • Checkbox fields are exported with the wrong state.
  • Checkbox fields that have a value set to No are exported with the wrong state.
  • Importing a document containing Location with the only page in it causes ArgumentOutOfRangeException.
  • Scrolling a large document causes an OutOfMemoryException.
  • RadFixedPage`s MediaBox and CropBox are not copied when calling the RadFixedDocument.Clone() method.


  • Exporting sheet properties corrupts the file and it cannot be opened in Excel.
  • An exception is thrown when calling AccountingFormatStringBuilder.BuildFormatString.
  • The column cannot be auto-fitted when it contains cells merged across rows.


  • Introduced API for exporting the page setup. Now you can set page settings for printing like orientation, size, scale factor, and fit to contents.
  • Intruduced API for setting culture-independent number formats.
  • Some applications like Open Office cannot import dates exported with SpreadStreamProcessing.
  • Measuring cell content size leads to wrong results.


  • Introduced support for column width defined inside colgroup and col tags when importing HTML.
  • Introduced a way to replace text with other document elements.
  • An exception is thrown trying to import HTML that contains width with an empty value.
  • InvalidOperationException is thrown while importing DOC file with invalid tab stop leader value.
  • List indent is respected instead of locally set paragraph indent when exporting to PDF.
  • NullReference exception when importing document with fields and a table in the footer.
  • When the inline image has only the width set, the image size is wrongly calculated when converting to PDF.
  • Fixed image size set in style does not respect unit type.
  • Missing images after importing a DOC file.
  • A NotSupportedException is thrown while importing DOC file with tab stops that are aligned to lists.
  • Numeric formatting of merge field is not respected when the data is set as double or float.
  • Wrong numbering position when a paragraph contains numbering in the style and a page break.
  • HtmlFormatProvider: KeyNotFoundException is thrown while exporting list whose first level has RestartAfterLevel=0.
  • A NullReferenceException is thrown when importing DOCX document containing AltChunk element.
  • Missing content when exporting a document containing a Field that has no Separator set.

New features & Roadmap

Have a feature request?

Post your feedback via the WinForms UserVoice portal or the Public forums

What's new across all Telerik products?

See all updates

Get Started Waves

Next Steps

Online help

Access our online documentation.

Compare pricing

Check out the offers. Purchase an individual suite or treat yourself to one of our bundles.

Download 30-day free trial

Try UI for WinForms with dedicated technical support.