Last Updated: 14 Sep 2020 15:09 by ADMIN

We got an issue with the Winforms grid view component while displaying a negative TimeSpan.
Last Updated: 01 Sep 2020 14:57 by ADMIN
Release R3 2020

Currently, due to the specificity of the internal implementation for this scrolling behavior, the possible solution that I can suggest is to hide the row header by setting the ShowRowHeaderColumn property to false

this.radGridView1.ShowRowHeaderColumn = false;

Last Updated: 21 Aug 2020 16:27 by ADMIN
Release R3 2020
Created by: devops
Comments: 3
Category: GridView
Type: Bug Report

Hi Telerik Teams,

I have a problem´╝îWhen I filter data in gridview, a RadForm appears. But there are problems with the margins of its 2 buttons. How can I deal with it?


Mason Chiu


Last Updated: 21 Aug 2020 15:54 by ADMIN
Release R3 2020
Created by: Radu
Comments: 1
Category: GridView
Type: Bug Report

GridView is not correctly drawn if it's not populated and the theme is set to "TelerikMetro" or "TelerikMetroBlue" (the bottom line is missing). 

Steps to reproduce the behavior: create a RadForm, add a RadGridView to it and set the theme to "TelerikMetro" or "TelerikMetroBlue" by using ThemeResolutionService.ApplicationThemeName.

Last Updated: 21 Aug 2020 13:51 by ADMIN
Release R3 2020 (LIB 2020.2.825)


Please refer to 2 attached files...

The 'April 2020' file is correct - The yellow color is shown upon setting a filter (Release 2020.1.113.40)

The 'June 2020' file is incorrect - No color is shown indicating filter is set. (Release 2020.2.512.40)

The code sets FilterDescriptor on the 'A PARTY' column.

There is change in the icon of the filter as well :(

Last Updated: 21 Aug 2020 12:32 by ADMIN
Release R3 2020 (LIB 2020.2.826)

To reproduce:

1. Expand a parent row in hierarchical grid.

2. Click on the second tab

3. If the child grid doesn't have any rows, the CurrentViewChanged event will not fire.

Last Updated: 21 Aug 2020 12:32 by ADMIN
Release R3 2020 (LIB 2020.2.826)

001.png: On the GridViewComboBoxColumn how do I prevent the drop down from covering the input cell when grid is at the bottom of the screen's viewable area?

I've tried setting the position and location under the CellEditorInitialized event, but had no luck.


private void RadGridARCashReceipt_CellEditorInitialized(object sender, GridViewCellEventArgs e)
            if (e.ActiveEditor is RadDropDownListEditor)
                RadDropDownListEditor editor = e.ActiveEditor as RadDropDownListEditor;
                if (editor != null)
                    RadDropDownListEditorElement ddlElement = (RadDropDownListEditorElement)editor.EditorElement;
                    ddlElement.EnableMouseWheel = false;

                    ddlElement.DropDownMinSize = new Size(200, 200);
                    ddlElement.AutoCompleteSuggest.DropDownList.DropDownMinSize = new Size(200, 200);

                    //ddlElement.AutoCompleteSuggest.DropDownList.Location = new Point(1000, 1000);                    
Last Updated: 17 Aug 2020 14:27 by ADMIN
Created by: dev
Comments: 2
Category: GridView
Type: Bug Report


I have a question regarding RadGridView. When I edit a cell in GridView and then click on a button (outside of gridview) immediately (i.e I don't click on another cell to exit edit mode), the Gridview is still edit mode. Please refer to the short video named "Without Using EndEdit()" to easily understand my point here.

In order to exit the edit mode, I try the following code:

    Private Sub CustomGridView_LostFocus(sender As Object, e As EventArgs) Handles Me.LostFocus
    End Sub

With this code, the gridview does exit the edit mode when I click on another button. But there is a problem with this method is that afterwards, I cannot edit the cell anymore.  Please refer to the short video named "Using EndEdit()" to better understand the problem.

So my question here is, is there any way that I can exit edit mode when clicking on another button right after editing a cell?

Thank you for your help.

Best regards,



Last Updated: 06 Aug 2020 09:38 by ADMIN

Please refer to the attached sample project. 

If the main Cars list is not empty, the child templates have correct captions:

However, if initially there are no Cars and you add a new one via the new row, the captions of the child template remains with the default value ("table"):

Last Updated: 15 Jul 2020 13:12 by ADMIN

Currently, when you update the value of the checkbox cell (toggle/untoggle), Narrator reads the value only the first time after selecting the cell. Each next checking/unchecking does nothing.

It is expected from the Narrator to read the value of the RadCheckBoxEditor when it is being activated after entering edit mode. It the column uses EditMode.OnValueChange, the value changes also should be read by the Narrator.

Last Updated: 14 Jul 2020 05:30 by ADMIN
Created by: Vivek
Comments: 0
Category: GridView
Type: Feature Request
Currently, the summary rows can't be selected since they are system rows and they are not read by the Narrator.
Last Updated: 07 Jul 2020 08:23 by ADMIN
Release R3 2020 (LIB 2020.2.713)


We are experiencing a strange behaviour of RadGridView set as a self referencing hierarchy when used with Excel filters.

Once we use predefined filter values (both, build-in and custom defined by us) the filter icon is highlitghted when none of the filter is marked. This higlight can be removed when clear filters button of filter popup is used or FilterDescriptors are cleared. If we do not clear the filters manually, and, for instance, sort grid column the application crashes with internal error of the grid. Error reads Object reference not set to an instance of object.

Attached movie will explain it better. I have also attached a ver simple sample project with data (which does not make sense, just for visualisation) that should fail when you repeat steps described above (turn today or last 7 days filter, apply, select no filter, apply and try to sort the same column).

Is there a workaround or specific conditions we need to apply to have it working?

Thanks for your advice.

I'm also attaching errors details:

  Message=Object reference not set to an instance of object. /this message comes in Polish, translated
   at Telerik.WinControls.UI.GridViewTemplate.PerformHierarchyFilter(GridViewRowInfo rowInfo)
   at Telerik.WinControls.Data.RadCollectionView`1.PassesFilter(TDataItem item)
   at Telerik.Collections.Generic.HybridIndex`1.GetFilteredItems(IEnumerable`1 e)
   at Telerik.Collections.Generic.HybridIndex`1.PerformWithQuickSort()
   at Telerik.Collections.Generic.HybridIndex`1.Perform()
   at Telerik.Collections.Generic.HybridIndex`1.get_Items()
   at Telerik.Collections.Generic.Index`1.get_Count()
   at Telerik.WinControls.Data.GroupBuilder`1.get_Groups()
   at Telerik.WinControls.Data.SnapshotCollectionView`1.get_Groups()
   at Telerik.WinControls.UI.GridViewInfo.LoadHierarchicalData(GridViewHierarchyRowInfo parent, ICollectionView`1 sourceView)
   at Telerik.WinControls.UI.GridViewInfo.Refresh()
   at Telerik.WinControls.UI.GridViewInfo.get_ChildRows()
   at Telerik.WinControls.UI.GridTableElement.UpdateViewCore(Object sender, DataViewChangedEventArgs args)
   at Telerik.WinControls.UI.GridTableElement.UpdateView(Object sender, DataViewChangedEventArgs args)
   at Telerik.WinControls.UI.GridTableElement.ProcessTemplateEvent(GridViewEvent eventData)
   at Telerik.WinControls.UI.GridTableElement.Telerik.WinControls.UI.IGridViewEventListener.ProcessEvent(GridViewEvent eventData)
   at Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessCollection(GridViewEvent gridEvent, PriorityWeakReferenceList list, GridEventProcessMode processMode)
   at Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessEvent(GridViewEvent gridEvent)
   at Telerik.WinControls.UI.GridViewSynchronizationService.NotifyListeners(GridViewEvent gridEvent)
   at Telerik.WinControls.UI.GridViewSynchronizationService.FlushEvents()
   at Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewEvent gridEvent)
   at Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewTemplate template, GridViewEvent eventData, Boolean postUI)
   at Telerik.WinControls.UI.GridViewTemplate.DispatchEvent(GridViewEvent gridEvent, Boolean postUI)
   at Telerik.WinControls.UI.GridViewTemplate.DispatchDataViewChangedEvent(Object sender, DataViewChangedEventArgs args)
   at Telerik.WinControls.UI.GridViewTemplate.OnViewChanged(Object sender, DataViewChangedEventArgs e)
   at Telerik.WinControls.UI.MasterGridViewTemplate.OnViewChanged(Object sender, DataViewChangedEventArgs e)
   at Telerik.WinControls.UI.GridViewTemplate.CollectionView_CollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
   at Telerik.WinControls.Data.RadCollectionView`1.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
   at Telerik.WinControls.Data.RadDataView`1.RebuildData(Boolean notify)
   at Telerik.WinControls.Data.RadDataView`1.RefreshOverride()
   at Telerik.WinControls.Data.RadDataView`1.OnNotifyPropertyChanged(PropertyChangedEventArgs e)
   at Telerik.WinControls.Data.RadCollectionView`1.OnNotifyPropertyChanged(String propertyName)
   at Telerik.WinControls.Data.RadCollectionView`1.sortDescriptors_CollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
   at Telerik.Collections.Generic.NotifyCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
   at Telerik.WinControls.UI.GridViewSortDescriptorCollection.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
   at Telerik.Collections.Generic.NotifyCollection`1.InsertItem(Int32 index, T item)
   at Telerik.WinControls.Data.SortDescriptorCollection.InsertItem(Int32 index, SortDescriptor item)
   at Telerik.WinControls.UI.GridViewSortDescriptorCollection.InsertItem(Int32 index, SortDescriptor item)
   at System.Collections.ObjectModel.Collection`1.Add(T item)
   at Telerik.WinControls.UI.GridViewColumn.Sort(RadSortOrder sortOrder, Boolean multiSortMode)
   at Telerik.WinControls.UI.GridHeaderCellElement.Sort(RadSortOrder sortOrder)
   at Telerik.WinControls.UI.GridHeaderRowBehavior.OnMouseUp(MouseEventArgs e)
   at Telerik.WinControls.UI.BaseGridBehavior.OnMouseUp(MouseEventArgs e)
   at Telerik.WinControls.UI.RadGridView.OnMouseUp(MouseEventArgs e)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   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.RadGridView.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.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
   at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
   at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
   at bindingListEx_celLike.My.MyApplication.Main(String[] Args) in :line 81

Last Updated: 07 Jul 2020 08:23 by ADMIN
Release R3 2020 (LIB 2020.2.713)
When the grid is grouped and there are hidden summary rows, the summary rows are not exported.
Last Updated: 07 Jul 2020 08:16 by ADMIN
Release R3 2020 (LIB 2020.2.713)
Hello everyone,

We found one problem with the  RadListFilterPopup (WindowsForms)
when we use the char '/' to search the filter, our App close.

When we use one specific type of keyboard (with numeric and it has char '.' in it) the char '.'  make the same error.
Last Updated: 07 Jul 2020 05:16 by ADMIN
Created by: Pieter
Comments: 8
Category: GridView
Type: Bug Report

Steps to reproduce:

  • Create a RadGridView
  • DataBind the grid to a DataView (it might also fail for other kinds of databinding or content)
  • For a column, call BestFit().
  • Remove that column from the grid.
  • Add the Grid to a parent form or control 
  • Make the form/control visible.

When the grid is loaded and displayed, a NullReferenceException will be thrown:

Message             : Object reference not set to an instance of an object.
Type                : System.NullReferenceException
Source              : Telerik.WinControls.GridView
Stack trace         : Telerik.WinControls.UI.BestFitHelper.SetColumnWidth(GridViewColumn column, Single desiredWidth)
                      Telerik.WinControls.UI.BestFitHelper.BestFitColumnCore(GridViewColumn column, BestFitColumnMode mode)
                      Telerik.WinControls.UI.RowsContainerElement.MeasureOverride(SizeF availableSize)
                      Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
                      Telerik.WinControls.RadElement.Measure(SizeF availableSize)
                      Telerik.WinControls.UI.ScrollViewElement`1.MeasureViewElement(SizeF availableSize)
                      Telerik.WinControls.UI.ScrollViewElement`1.MeasureView(SizeF availableSize)
                      Telerik.WinControls.UI.ScrollViewElement`1.MeasureOverride(SizeF availableSize)
                      Telerik.WinControls.UI.GridTableElement.MeasureOverride(SizeF availableSize)
                      Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
                      Telerik.WinControls.RadElement.Measure(SizeF availableSize)
                      Telerik.WinControls.Layouts.DockLayoutPanel.MeasureOverride(SizeF constraint)
                      Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
                      Telerik.WinControls.RadElement.Measure(SizeF availableSize)
                      Telerik.WinControls.UI.LightVisualElement.MeasureElements(SizeF availableSize, SizeF clientSize, Padding borderThickness)
                      Telerik.WinControls.UI.LightVisualElement.MeasureOverride(SizeF availableSize)
                      Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
                      Telerik.WinControls.RadElement.Measure(SizeF availableSize)
                      Telerik.WinControls.RootRadElement.MeasureOverride(SizeF availableSize)
                      Telerik.WinControls.RootRadElement.MeasureCore(SizeF availableSize)
                      Telerik.WinControls.RadElement.Measure(SizeF availableSize)
                      Telerik.WinControls.RadElementTree.PerformInnerLayout(Boolean performMeasure, Int32 x, Int32 y, Int32 width, Int32 height)
                      Telerik.WinControls.RadControl.OnLoad(Size desiredSize)
                      Telerik.WinControls.UI.RadGridView.OnLoad(Size desiredSize)
                      Telerik.WinControls.RadControl.LoadElementTree(Size desiredSize)
                      System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
                      System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
                      System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
                      System.Windows.Forms.Control.SetVisibleCore(Boolean value)
                      Telerik.WinControls.UI.TabPanel.set_Visible(Boolean value)
                      Telerik.WinControls.UI.TabStripPanel.SetSelected(TabPanel tabPanel)
                      Telerik.WinControls.UI.TabStripPanel.UpdateTabSelection(Boolean updateFocus)
                      Telerik.WinControls.UI.Docking.DockTabStrip.UpdateTabSelection(Boolean updateFocus)
                      Telerik.WinControls.UI.Docking.ToolTabStrip.UpdateTabSelection(Boolean updateFocus)
                      Telerik.WinControls.UI.TabStripPanel.OnHandleCreated(EventArgs e)
                      System.Windows.Forms.Control.WmCreate(Message& m)
                      System.Windows.Forms.Control.WndProc(Message& m)
                      System.Windows.Forms.ScrollableControl.WndProc(Message& m)
                      Telerik.WinControls.RadControl.WndProc(Message& m)
                      Telerik.WinControls.UI.SplitPanel.WndProc(Message& m)
                      System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
                      System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
                      System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Last Updated: 06 Jul 2020 16:09 by ADMIN


Please find attached sample project having 2 different reference folder(Telerik2018,Telerik2020) for Telerik.

Code flow & Issue description: I have Event "radGridView1_EditorRequired" in which i have attached another event on value changed "Editor_ValueChanged" in which we get data gron DropdownListElement using ((RadDropDownListElement)(sender)).SelectedValue.
Issue is when we use version (2018.3.1016.40) we get selected value text, in case of current version (2020.1.218.40) we get null value.

Current version DLL  2020.1.218.40 (Issue in current version)
Previous version DLL 2018.3.1016.40 (Working fine)

Note : I have also attached both version of Telerik DLL in sample project, you can reproduce issue by referencing to 2020.1.218.40 version. After selecting values as shown in attached screenshot you will get null value as shown in another screenshot.

Please find attached screenshot  for selecting values to reproduce issue as well where we get null value.


Thanks and Regards

Last Updated: 01 Jul 2020 08:54 by ADMIN

I have a radGridView with MutliSelect set to true and SelectionMode set to FullRowSelect. A theme is applied, and this behavior is seen with other themes too. Several columns are pinned to the left.

When I multi-select rows using the shift or control buttons by clicking one of the cells under the frozen columns, the row is selected and colored accordingly, except for the cell that was actually clicked which remains with the unselected color.

If I multi-select by clicking on one of the cells under an unpinned column, the full row is selected as expected.

In the image below, I held down shift and selected the first and third row in sequence under the Officer column.

How can I fix this to show the complete row selected?

Last Updated: 29 Jun 2020 15:05 by ADMIN
To reproduce: please refer to the attached gif file. Apply a conditional formatting rule for the current time's minute. Then, after a minute later, try to edit the already applied rule and change the minute value, you will notice that the color is cleared, but the new one is not applied.

Workaround: use the CellFormatting event https://docs.telerik.com/devtools/winforms/gridview/cells/formatting-cells
Last Updated: 23 Jun 2020 10:49 by ADMIN
When dragging a column to column chooser the text is overlapping columns added to the list.
Under Review
Last Updated: 23 Jun 2020 05:11 by ADMIN
Created by: Brandon
Comments: 1
Category: GridView
Type: Feature Request
Within the CellEndEdit event, the GridViewCellEventArgs should contain an item to Cancel/Undo which will revert the value of the cell back to the value it had when CellBeginEdit was called.
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