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RadPageView DragDrop - copy Row from RadPageView to System.Windows.Forms.DataGridView

Hello,

I’m working with some older forms that use System.Windows.Forms.DataGridView. The form is quite complex, so converting it to Telerik isn’t straightforward.

I’d like to copy a row from RadPageView. Could you please provide a sample code snippet showing how to achieve this?

Thank you!

Radek

GridView
Radek
Top achievements
Rank 2
Iron
Iron
Iron
 asked on 12 Dec 2025
0 answers
4 views
Behavior of the Text property in GridView CellFormatting event

Hello,

I have a question about the behavior of the Text property in the CellFormatting event in GridView. I understand that GridView uses UI virtualization, and that I need to reset all modified properties for the rest of cells. But how does the Text property behave? I looked through the forum and found this example:

private void radGridView1_CellFormatting(object sender, CellFormattingEventArgs e)
        {
            if (e.Column.Name == "Description")
            {
                e.CellElement.Text = e.CellElement.Value + " END";
                e.CellElement.Image = Properties.Resources.OutlookViewCalendar;
                e.CellElement.DrawImage = true;
                e.CellElement.TextImageRelation = TextImageRelation.TextBeforeImage;
            }
            else
            { 
                e.CellElement.ResetValue(LightVisualElement.ImageProperty, ValueResetFlags.Local);
                e.CellElement.ResetValue(LightVisualElement.DrawImageProperty, ValueResetFlags.Local);
                e.CellElement.ResetValue(LightVisualElement.TextImageRelationProperty, ValueResetFlags.Local);
            }
        }

In this example, all properties are reset except Text. When I tried to reset Text, all cell texts disappeared, except the ones I set manually in CellFormatting. So I think Text has special behavior in CellFormatting, and it's always set from Value at the beginning and it's not affected by UI virtualization and reusing cells. Is that correct?

Also, just to be sure, in all examples I saw the if/else pattern. But functionally, is it the same as if I reset all properties I want to change at the beginning, and then set them later? Or can this have some performance impact? The reason I ask is that I use a switch with more branches, and it would be hard to track what needs to be reset in each one.

Here is my case. And I was also thinking, in my case, is it correct to reset the properties before checking ColumnIndex and RowIndex, or after?

private void rgv_CellFormatting(object sender, CellFormattingEventArgs e)
		{
			e.CellElement.ResetValue(LightVisualElement.BackColorProperty, ValueResetFlags.Local);
			e.CellElement.ResetValue(LightVisualElement.NumberOfColorsProperty, ValueResetFlags.Local);
			e.CellElement.ResetValue(LightVisualElement.DrawFillProperty, ValueResetFlags.Local);
			e.CellElement.ResetValue(LightVisualElement.PaddingProperty, ValueResetFlags.Local);
			//e.CellElement.ResetValue(LightVisualElement.TextProperty, ValueResetFlags.Local);

			if ((e.ColumnIndex < 0) || (e.RowIndex < 0))
				return;

			var ed = e.Row.DataBoundItem as TestParEditorItem;
			if (ed == null)
				return;

			bool isSub = ed.IsSubItem;
			bool hasSub = ed.HasSubItems;

			switch (e.Column.Name)
			{
				case "colR":
				case "colFi":
				case "colR2":
				case "colFi2":
					if (isSub)
						e.CellElement.Text = "";
					break;

				case "colMin":
				case "colMax":
					if (hasSub)
						e.CellElement.Text = "";
					break;

				case "colAct":
					e.CellElement.BackColor = SystemColors.ControlLight;
					e.CellElement.NumberOfColors = 1;
					e.CellElement.DrawFill = true;
					break;

				case "colType":
					if (isSub)
					{
						e.CellElement.Text = ed.SubItemName;
						e.CellElement.Padding = new Padding(30, 0, 0, 0);
					}
					else
					{
						e.CellElement.Padding = new Padding(0, 0, 0, 0);
					}
					break;
			}
		}

Thanks.

GridView
Marian
Top achievements
Rank 2
Bronze
Iron
Iron
 asked on 11 Dec 2025
6 answers
188 views
Self-referencing grid with missing parent items.

Hi.

 

I'm facing and issue with displaying hierarchical data (self-referencing) in grid when missing parent items in data source - only part of data is displayed.

 

1. Add grid to form

1.var grid = new RadGridView {Dock = DockStyle.Fill};
2.this.Controls.Add(grid);
3.grid.Columns.Add("cName","Name","Name"); //Dummy column displaying Name

 

2. Setup self-referencing

1.var col1 = new GridViewTextBoxColumn("hiddenColumnId", "Id");
2.var col2 = new GridViewTextBoxColumn("hiddenColumnParentId", "ParentId");
3.grid.MasterTemplate.Columns.Add(col1);
4.grid.MasterTemplate.Columns.Add(col2);
5.grid.Columns["hiddenColumnId"].IsVisible = false;
6.grid.Columns["hiddenColumnParentId"].IsVisible = false;
7.grid.Relations.AddSelfReference(grid.MasterTemplate, "hiddenColumnId", "hiddenColumnParentId");

 

3. Create dummy data type

01.class Item
02.{
03.    public Item(int id, string name, int? parentId = null)
04.    {
05.        Id = id;
06.        Name = name;
07.        ParentId = parentId;
08.    }
09. 
10.    public int Id { get; set; }
11.    public string Name { get; set; }
12.    public int? ParentId { get; set; }
13.}

 

4. Add new data source

01.var items = new List<Item>
02.{
03.    new Item(1,"1"),
04.    new Item(2,"1.1",1),
05.    new Item(3,"1.2",1),
06.    new Item(7,"1.2.1",3),
07.    new Item(4,"2"),
08.    new Item(5,"2.1",4),
09.    new Item(6,"2.2",4)
10.};
11.grid.DataSource = items;

 

And as expected a correct tree structure is displayed

1.1
2.-1.1
3.-1.2
4.--1.2.1
5.2
6.-2.1
7.-2.2

 

 

However in my case due to busines logic I have only a subset of data - all except item "1" and "2".

Instead of ex

1.1.1
2.1.2
3.-1.2.1
4.2.1
5.2.2

 

I can see only children of first missing parent item. Although the number of rows is matching correct total number of item to be displayed (5) only part of items are visible (3).

1.1.1
2.1.2
3.-1.2.1

 

 

As a workaroud I can modify data source and remove parent assignement from objects if parent is missing in data source either on data preparation or DataBindingComplete event.

01.private void Grid_DataBindingComplete(object sender, GridViewBindingCompleteEventArgs e)
02. {
03.     var grid = sender as RadGridView;
04.      
05.    // Get existing items
06.     var ids = new List<object>();
07.     foreach (var id in grid.Columns["hiddenColumnId"].DistinctValues)
08.     {
09.         ids.Add(id);
10.     }
11. 
12.    // Remove missing parents
13.    foreach (var row in grid.Rows)
14.    {
15.        var parentId = row.Cells["hiddenColumnParentId"].Value;
16.        if (!ids.Contains(parentId))
17.            row.Cells["hiddenColumnParentId"].Value = null;
18.    }
19.}

 

 

However this solution is not suitable, because it is modifying data providing inconsistant state - using that data in code I may falsly assume that the item does not have a parent while it has.

 

Any ideas how to solve this issue?

 

Regargs
Greg

GridView
Zander
Top achievements
Rank 2
Iron
 answered on 05 Dec 2025
2 answers
37 views
Bug in changed PageViewMode with nested levels (WinForms)

Hi

I refer to the aritcle "How to Change PageViewMode for the Nested Levels in RadGridView - Telerik UI for WinForms"

I have a setting implemented that is like in the article.

It is working but has a flaw:

When an entry of the second tier is expanded and I then collapse the corresponding entry in the first tier and re-expand it, I get an NullReferenceException coming out of Telerik code:


System.NullReferenceException: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.
   bei Telerik.WinControls.UI.RowsContainerElement.UpdateMergeCells(GridCellElement cellElement)
   bei Telerik.WinControls.UI.RowsContainerElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.ScrollViewElement`1.ArrangeViewElement(RectangleF viewElementRect)
   bei Telerik.WinControls.UI.ScrollViewElement`1.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.RadPageViewElementBase.ArrangeChildren(SizeF finalSize)
   bei Telerik.WinControls.UI.RadPageViewElementBase.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.RadPageViewExplorerBarElement.ArrangeContent(RectangleF clientRect)
   bei Telerik.WinControls.UI.RadPageViewExplorerBarElement.PerformArrange(RectangleF clientRect)
   bei Telerik.WinControls.UI.RadPageViewElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.UI.RadPageViewExplorerBarElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.LightVisualElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.GridDetailViewRowElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.VirtualizedStackContainer`1.ArrangeElementCore(RadElement element, SizeF finalSize, RectangleF arrangeRect)
   bei Telerik.WinControls.UI.VirtualizedStackContainer`1.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.UI.ScrollableRowsContainerElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.RowsContainerElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.ScrollViewElement`1.ArrangeViewElement(RectangleF viewElementRect)
   bei Telerik.WinControls.UI.ScrollViewElement`1.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.RadPageViewElementBase.ArrangeChildren(SizeF finalSize)
   bei Telerik.WinControls.UI.RadPageViewElementBase.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.RadPageViewExplorerBarElement.ArrangeContent(RectangleF clientRect)
   bei Telerik.WinControls.UI.RadPageViewExplorerBarElement.PerformArrange(RectangleF clientRect)
   bei Telerik.WinControls.UI.RadPageViewElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.UI.RadPageViewExplorerBarElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.LightVisualElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.GridDetailViewRowElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.VirtualizedStackContainer`1.ArrangeElementCore(RadElement element, SizeF finalSize, RectangleF arrangeRect)
   bei Telerik.WinControls.UI.VirtualizedStackContainer`1.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.UI.ScrollableRowsContainerElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.RowsContainerElement.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.UI.ScrollViewElement`1.ArrangeViewElement(RectangleF viewElementRect)
   bei Telerik.WinControls.UI.ScrollViewElement`1.ArrangeOverride(SizeF finalSize)
   bei Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
   bei Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
   bei Telerik.WinControls.Layouts.ContextLayoutManager.UpdateLayout()
   bei Telerik.WinControls.UI.GridTableElement.UpdateOnRowExpandedCore(GridViewRowInfo row)
   bei Telerik.WinControls.UI.GridTableElement.UpdateOnRowExpanded(GridViewRowInfo row)
   bei Telerik.WinControls.UI.GridTableElement.UpdateOnRowPropertyChanged(GridViewRowInfo row, GridPropertyChangedEventArgs e)
   bei Telerik.WinControls.UI.GridTableElement.ProcessRowEvent(GridViewRowInfo row, GridViewEvent eventData)
   bei Telerik.WinControls.UI.GridTableElement.Telerik.WinControls.UI.IGridViewEventListener.ProcessEvent(GridViewEvent eventData)
   bei Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessCollection(GridViewEvent gridEvent, PriorityWeakReferenceList list, GridEventProcessMode processMode)
   bei Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessEvent(GridViewEvent gridEvent)
   bei Telerik.WinControls.UI.GridViewSynchronizationService.NotifyListeners(GridViewEvent gridEvent)
   bei Telerik.WinControls.UI.GridViewSynchronizationService.FlushEvents()
   bei Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewEvent gridEvent)
   bei Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewTemplate template, GridViewEvent eventData, Boolean postUI)
   bei Telerik.WinControls.UI.GridViewRowInfo.DispatchEvent(KnownEvents id, GridEventType type, GridEventDispatchMode dispatchMode, Object originator, Object[] arguments)
   bei Telerik.WinControls.UI.GridViewRowInfo.OnPropertyChanged(PropertyChangedEventArgs args)
   bei Telerik.WinControls.UI.GridViewDataRowInfo.OnPropertyChanged(PropertyChangedEventArgs e)
   bei Telerik.WinControls.UI.GridViewHierarchyRowInfo.OnPropertyChanged(PropertyChangedEventArgs e)
   bei Telerik.WinControls.UI.GridViewRowInfo.SetBooleanProperty(String propertyName, Int32 propertyKey, Boolean value)
   bei Telerik.WinControls.UI.GridViewRowInfo.set_IsExpanded(Boolean value)
   bei Telerik.WinControls.UI.GridGroupExpanderCellElement.expander_RadPropertyChanged(Object sender, RadPropertyChangedEventArgs e)
   bei Telerik.WinControls.RadPropertyChangedEventHandler.Invoke(Object sender, RadPropertyChangedEventArgs e)
   bei Telerik.WinControls.RadObject.OnPropertyChanged(RadPropertyChangedEventArgs e)
   bei Telerik.WinControls.RadElement.OnPropertyChanged(RadPropertyChangedEventArgs e)
   bei Telerik.WinControls.VisualElement.OnPropertyChanged(RadPropertyChangedEventArgs e)
   bei Telerik.WinControls.RadComponentElement.OnPropertyChanged(RadPropertyChangedEventArgs e)
   bei Telerik.WinControls.RadItem.OnPropertyChanged(RadPropertyChangedEventArgs e)
   bei Telerik.WinControls.UI.UIItemBase.OnPropertyChanged(RadPropertyChangedEventArgs e)
   bei Telerik.WinControls.UI.LightVisualElement.OnPropertyChanged(RadPropertyChangedEventArgs e)
   bei Telerik.WinControls.UI.ExpanderItem.OnPropertyChanged(RadPropertyChangedEventArgs e)
   bei Telerik.WinControls.RadObject.RaisePropertyNotifications(RadPropertyValue propVal, Object oldValue, Object newValue, ValueSource oldSource)
   bei Telerik.WinControls.RadObject.SetValueCore(RadPropertyValue propVal, Object propModifier, Object newValue, ValueSource source)
   bei Telerik.WinControls.RadElement.SetValueCore(RadPropertyValue propVal, Object propModifier, Object newValue, ValueSource source)
   bei Telerik.WinControls.UI.ExpanderItem.set_Expanded(Boolean value)
   bei Telerik.WinControls.UI.GridExpanderItem.set_Expanded(Boolean value)
   bei Telerik.WinControls.UI.ExpanderItem.ToggleExpanded()
   bei Telerik.WinControls.UI.ExpanderItem.OnMouseUp(MouseEventArgs e)
   bei Telerik.WinControls.RadElement.OnCLREventsRise(RoutedEventArgs args)
   bei Telerik.WinControls.RadElement.OnBubbleEvent(RadElement sender, RoutedEventArgs args)
   bei Telerik.WinControls.RadElement.RaiseBubbleEvent(RadElement sender, RoutedEventArgs args)
   bei Telerik.WinControls.RadItem.RaiseBubbleEvent(RadElement sender, RoutedEventArgs args)
   bei Telerik.WinControls.RadElement.RaiseRoutedEvent(RadElement sender, RoutedEventArgs args)
   bei Telerik.WinControls.RadElement.DoMouseUp(MouseEventArgs e)
   bei Telerik.WinControls.ComponentInputBehavior.OnMouseUp(MouseEventArgs e)
   bei Telerik.WinControls.RadControl.OnMouseUp(MouseEventArgs e)
   bei Telerik.WinControls.UI.RadGridView.OnMouseUp(MouseEventArgs e)
   bei System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   bei System.Windows.Forms.Control.WndProc(Message& m)
   bei System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   bei Telerik.WinControls.RadControl.WndProc(Message& m)
   bei Telerik.WinControls.UI.RadGridView.WndProc(Message& m)
   bei System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   bei System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   bei System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

GridView
Julian
Top achievements
Rank 1
Iron
Iron
Iron
 updated answer on 27 Nov 2025
5 answers
162 views
ArgumentExceptions and InvalidOperationExceptions when calling RadGridView.EndUpdate()

Hello,

we have an application using Telerik version 2021.3.1123.40. It is not the first time these errors were reportet, but I have no methode to reproduce it at the moment. The chain of Events for both errors is, that RadGridView.FilterChanged-Event is called, from there we call our method "UpdateProzessschritte" (UpdateProcessSteps), which does a BeginUpdate and EndUpdate of the grid. When EndUpdate is called, the 2 errors orccured under certain, unknown conditions.

  1. ERROR|TBM_HAProzessPlugin.MainForm|1|(null)| In Modul TBM|DNA - Digitaler Netzanschluss ist ein Fehler aufgetreten. System.InvalidOperationException: Die Auflistung wurde geändert. Der Enumerationsvorgang kann möglicherweise nicht ausgeführt werden.
       bei System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
       bei System.Collections.Generic.List`1.Enumerator.MoveNextRare()
       bei System.Collections.Generic.List`1.Enumerator.MoveNext()
       bei Telerik.WinControls.UI.DataGroup.<GetEnumerator>d__7.MoveNext()
       bei Telerik.WinControls.UI.GridViewGroupRowInfo.get_ChildRows()
       bei Telerik.WinControls.UI.GridViewRowInfo.HasChildRows()
       bei Telerik.WinControls.UI.GridTraverser.CanStepInHierarchy()
       bei Telerik.WinControls.UI.GridTraverser.StepInHierarchy()
       bei Telerik.WinControls.UI.GridTraverser.MoveNextCore()
       bei Telerik.WinControls.UI.GridTraverser.MoveNext()
       bei Telerik.WinControls.UI.GridTraverser.GoToRow(GridViewRowInfo row)
       bei Telerik.WinControls.UI.BaseGridNavigator.ProcessEventCore(GridViewEvent eventData)
       bei Telerik.WinControls.UI.BaseGridNavigator.Telerik.WinControls.UI.IGridViewEventListener.ProcessEvent(GridViewEvent eventData)
       bei Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessCollection(GridViewEvent gridEvent, PriorityWeakReferenceList list, GridEventProcessMode processMode)
       bei Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessEvent(GridViewEvent gridEvent)
       bei Telerik.WinControls.UI.GridViewSynchronizationService.NotifyListeners(GridViewEvent gridEvent)
       bei Telerik.WinControls.UI.GridViewSynchronizationService.FlushEvents()
       bei Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewEvent gridEvent)
       bei Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewTemplate template, GridViewEvent eventData, Boolean postUI)
       bei Telerik.WinControls.UI.GridViewTemplate.DispatchEvent(GridViewEvent gridEvent, Boolean postUI)
       bei Telerik.WinControls.UI.GridViewTemplate.DispatchDataViewChangedEvent(Object sender, DataViewChangedEventArgs args)
       bei Telerik.WinControls.UI.GridViewTemplate.OnViewChanged(Object sender, DataViewChangedEventArgs e)
       bei Telerik.WinControls.UI.MasterGridViewTemplate.OnViewChanged(Object sender, DataViewChangedEventArgs e)
       bei Telerik.WinControls.UI.GridViewTemplate.EndUpdate(Boolean notify, DataViewChangedEventArgs e)
       bei Telerik.WinControls.UI.MasterGridViewTemplate.EndUpdate(Boolean notify, DataViewChangedEventArgs e)
       bei Telerik.WinControls.UI.GridViewTemplate.EndUpdate()
       bei Telerik.WinControls.UI.RadGridView.EndUpdate()
       bei TBM_HAProzessPlugin.MainForm.UpdateProzessschritte(RadGridView radGridView, RadDiagram radDiagram, Dictionary`2 prozessDauerListe, List`1 schritte) in C:\Program Files (x86)\Jenkins\jobs\TBM_DNA_Digitaler_Netzanschluss_WP\workspace\TBM_HAProzessPlugin\src\Forms\MainForm.cs:Zeile 510.
       bei TBM_HAProzessPlugin.MainForm.rgvHAAkten_FilterChanged(Object sender, GridViewCollectionChangedEventArgs e) in C:\Program Files (x86)\Jenkins\jobs\TBM_DNA_Digitaler_Netzanschluss_WP\workspace\TBM_HAProzessPlugin\src\Forms\MainForm.cs:Zeile 442.

    [Translation]: Collection was modified; enumeration operation may not execute


  2. ERROR|TBM_HAProzessPlugin.MainForm|1|(null)| In Modul TBM|DNA - Digitaler Netzanschluss ist ein Fehler aufgetreten. System.ArgumentException: Ein Element mit dem gleichen Schlüssel wurde bereits hinzugefügt.
       bei System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
       bei System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
       bei System.Collections.Generic.Dictionary`2.Add(TKey key, TValue value)
       bei Telerik.WinControls.Data.GroupBuilder`1.Perform(IReadOnlyCollection`1 items, Int32 level, Group`1 parent)
       bei Telerik.WinControls.Data.GroupBuilder`1.get_Groups()
       bei Telerik.WinControls.Data.RadDataView`1.get_Groups()
       bei Telerik.WinControls.UI.GridViewInfo.Refresh()
       bei Telerik.WinControls.UI.GridViewInfo.get_ChildRows()
       bei Telerik.WinControls.UI.GridViewTemplate.get_ChildRows()
       bei Telerik.WinControls.UI.ViewInfoTraverser.SetCollectionForStage(Boolean initializeCollection)
       bei Telerik.WinControls.UI.ViewInfoTraverser.ChangeCollectionForward()
       bei Telerik.WinControls.UI.ViewInfoTraverser.MoveNextCore()
       bei Telerik.WinControls.UI.ViewInfoTraverser.MoveNext()
       bei Telerik.WinControls.UI.GridTraverser.MoveNextCore()
       bei Telerik.WinControls.UI.GridTraverser.MoveNext()
       bei Telerik.WinControls.UI.GridTraverser.GoToRow(GridViewRowInfo row)
       bei Telerik.WinControls.UI.BaseGridNavigator.ProcessEventCore(GridViewEvent eventData)
       bei Telerik.WinControls.UI.BaseGridNavigator.Telerik.WinControls.UI.IGridViewEventListener.ProcessEvent(GridViewEvent eventData)
       bei Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessCollection(GridViewEvent gridEvent, PriorityWeakReferenceList list, GridEventProcessMode processMode)
       bei Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessEvent(GridViewEvent gridEvent)
       bei Telerik.WinControls.UI.GridViewSynchronizationService.NotifyListeners(GridViewEvent gridEvent)
       bei Telerik.WinControls.UI.GridViewSynchronizationService.FlushEvents()
       bei Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewEvent gridEvent)
       bei Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewTemplate template, GridViewEvent eventData, Boolean postUI)
       bei Telerik.WinControls.UI.GridViewTemplate.DispatchEvent(GridViewEvent gridEvent, Boolean postUI)
       bei Telerik.WinControls.UI.GridViewTemplate.DispatchDataViewChangedEvent(Object sender, DataViewChangedEventArgs args)
       bei Telerik.WinControls.UI.GridViewTemplate.OnViewChanged(Object sender, DataViewChangedEventArgs e)
       bei Telerik.WinControls.UI.MasterGridViewTemplate.OnViewChanged(Object sender, DataViewChangedEventArgs e)
       bei Telerik.WinControls.UI.GridViewTemplate.EndUpdate(Boolean notify, DataViewChangedEventArgs e)
       bei Telerik.WinControls.UI.MasterGridViewTemplate.EndUpdate(Boolean notify, DataViewChangedEventArgs e)
       bei Telerik.WinControls.UI.GridViewTemplate.EndUpdate()
       bei Telerik.WinControls.UI.RadGridView.EndUpdate()
       bei TBM_HAProzessPlugin.MainForm.UpdateProzessschritte(RadGridView radGridView, RadDiagram radDiagram, Dictionary`2 prozessDauerListe, List`1 schritte) in C:\Program Files (x86)\Jenkins\jobs\TBM_DNA_Digitaler_Netzanschluss_WP\workspace\TBM_HAProzessPlugin\src\Forms\MainForm.cs:Zeile 510.
       bei TBM_HAProzessPlugin.MainForm.rgvHAAkten_FilterChanged(Object sender, GridViewCollectionChangedEventArgs e) in C:\Program Files (x86)\Jenkins\jobs\TBM_DNA_Digitaler_Netzanschluss_WP\workspace\TBM_HAProzessPlugin\src\Forms\MainForm.cs:Zeile 442.

    [Translation]: Item with Same Key has already been added

 

Do you have any ideas which causes could lead to this exceptions and how to fix it? Or is this a known problem which was already fixed in later versions?

GridView
Stephan
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Iron
Iron
 updated answer on 05 Nov 2025
2 answers
82 views
Lagged when updated to 2023

Hi, my application is built on .NET 4 and Telerik 2023. However, after the update, I have experienced increased lag when loading radGridView What should I do?

GridView
Hosein
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Iron
 answered on 21 Oct 2025
18 answers
1.4K+ views
Load/Save Layout customization
Hey,

I'm loving the load and save layout feature of the RadGrid View. Very powerful tool to allow end users great control of how they want to view their data ;)

BUT I a mhaving one issue with it. I have implemented the Save Load layout as per the documentation and I save these XML to our database without issue  - Since this has been done my boss has requested I add columns and change the names of columns on some of the Grids. The problem is, the SaveLayout() XML is saving the entire column template of the  grid and when I have an additional data row and bind this to the DataSource of the Grid the new column is not appearing (I have a similar problem if I rename the column in the underlying data-source).

I've been tinkering with the SerializationMetadata and have been able to set this:

this.XmlSerializationInfo.DisregardOriginalSerializationVisibility = true;

And continue to make changes to how the columns themselves are saved. For example I was able to not save the format string - because this is again something we want control over in development.

To top this off, it's very FEW things that I want removed from the Original Meta Data and it is painstaking and very prone to error to add all these serialization values back after calling the clear() method as instructed by the documentation. 

Would love if anyone out there knows of a way to control WHICH columns exist via the datasource but still save the layout details of each columns - and if there's an easier approach to perhaps remove specific layout options instead of having to re-build the entire Serialization info.

Cheers, thanks for reading
Dave - Connect Direct
GridView
Matthew
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Rank 1
Iron
 answered on 14 Oct 2025
1 answer
37 views
How to configure a RadGridView to copy and paste like Excel?

If a user sees a grid that looks like Excel, they expect it to function the same as Excel. I'm not very familiar with Telerik grids, but the OOTB copy/paste functionality doesnt seem to work the identical to Excel.

Our users need to be able to select a single cell and paste a single cell. This seems to work.

They also need to be able to select a single cell and paste its value in many cells. This only seems to paste the value in the last selected cell, not all selected cells.

Before:

After

Select multiple continuous cells from a row and paste to a single cell, and have all copied cells pasted starting at the selected paste location. This seems to work

Select multiple continuous cells from a row and paste to a selection of continuous rows and have all copied cells pasted. This seems to only work on the last row

Before

After

Here are my current grid settings:

DataRadGrid.AllowAddNewRow = false;
DataRadGrid.AllowColumnChooser = false;
DataRadGrid.AllowColumnReorder = false;
DataRadGrid.AllowDeleteRow = false;
DataRadGrid.AllowEditRow = true;
DataRadGrid.AllowMultiColumnSorting = true;
DataRadGrid.AllowRowReorder = false;
DataRadGrid.AllowRowResize = false;

DataRadGrid.BeginEditMode = RadGridViewBeginEditMode.BeginEditOnKeystroke;
DataRadGrid.EnableAlternatingRowColor = true;
DataRadGrid.EnableCustomDrawing = true;
DataRadGrid.EnableFiltering = true;
DataRadGrid.EnableGrouping = false;
DataRadGrid.EnableHotTracking = false;
DataRadGrid.HorizontalScrollState = ScrollState.AlwaysShow;
DataRadGrid.MasterTemplate.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.None;
DataRadGrid.MasterTemplate.ShowFilteringRow = false;
DataRadGrid.MasterTemplate.ShowHeaderCellButtons = true;
DataRadGrid.MasterView.TableSearchRow.ShowClearButton = true;
DataRadGrid.MultiSelect = true;
DataRadGrid.SelectionMode = GridViewSelectionMode.CellSelect;
DataRadGrid.ShowColumnHeaders = true;
DataRadGrid.VerticalScrollState = ScrollState.AlwaysShow;
DataRadGrid.EnterKeyMode = RadGridViewEnterKeyMode.EnterMovesToNextRow;

Are there settings I can use to mimic Excel, if not, is there boilerplate code to achieve this?

Thanks,

matt

GridView
Dinko | Tech Support Engineer
Telerik team
 answered on 08 Oct 2025
1 answer
35 views
Winform GridView and DefaultValuesNeeded
Why isDefaultValuesNeeded not fired when programmatically adding a row to a gridview? 
GridView
Nadya | Tech Support Engineer
Telerik team
 answered on 07 Oct 2025
1 answer
32 views
Error with automatic management of the toolwindowsfamily.

message error: La référence d objet n'est pas définie à une instance d'un objet.

Hello,
In my Frame, I use a RadDock with documentContainer and two toolwindows.
I would like the toolWindowFamily to dock automatically when I select it, rather than having to press the “pin” image.

On the “stabstripItem_click”, I put: oToolwindow:DockState=  Telerik.WinControls.UI.Docking.DockState:Docked.

Here is my code:

 

METHOD PRIVATE VOID TabStripItem_Click( INPUT sender AS System.Object, INPUT e AS System.EventArgs ):

        DEFINE VARIABLE oTabStripItem AS Telerik.WinControls.UI.TabStripItem       NO-UNDO.
        DEFINE VARIABLE oToolwindow   AS Telerik.WinControls.UI.Docking.ToolWindow NO-UNDO.
        DEFINE VARIABLE cValeur       AS CHARACTER                                 NO-UNDO.        

        oTabStripItem = CAST(sender, Telerik.WinControls.UI.TabStripItem) NO-ERROR.
        IF oTabStripItem NE ? THEN 
        DO:
            oToolwindow = CAST(oTabStripItem:TabPanel, Telerik.WinControls.UI.Docking.ToolWindow) NO-ERROR.

            IF VALID-OBJECT(oToolwindow) THEN DO:

                IF oToolwindow NE ? THEN 
                DO:

                    IF THIS-OBJECT:DockPrincipal:ActiveWindow NE oToolwindow THEN 
                    DO:                     
                        oActiveWindow = THIS-OBJECT:DockPrincipal:ActiveWindow.
                        cValeur = THIS-OBJECT:oongFamilleListe:GetToolwindowFurtifValeur( oToolwindow:NAME ).

                        InitialiseToolWindow( oToolwindow:NAME ).
                        CASE oToolwindow:Name:                        
                            WHEN gcToolWindowNomAide[1] THEN DO:
                                IF cValeur NE "?" AND cValeur NE 'OFF'
                                    THEN THIS-OBJECT:oongCodeAnalytiqueAide:Initialisation(cValeur).                                
                                    ELSE THIS-OBJECT:oongCodeAnalytiqueAide:Initialisation("").

                                oToolwindow:Enabled = ( cValeur NE "?" AND cValeur NE 'OFF').        
                            END.
                            WHEN gcToolWindowNomFiltre[1] THEN DO:   

                               glDockParCode= YES.            
                               oToolwindow:DockState=  Telerik.WinControls.UI.Docking.DockState:Docked.
                               glDockParCode= NO.

                                oToolwindow:Enabled = YES.      
                                gcNoeudCourant = 'C000'.
                                glFiltreVisibleFamille = YES.  
                                oongFamilleArborescence:SelectionNoeud(gcNoeudCourant).

                                IF glRafraichir THEN DO:
                                    SetEtatObjet("BtnSupprimer", NO).                                    
                                    //SetEtatObjet("BtnCopier", NO).
                                    //SetEtatObjet("BtnColler", NO).
                                    //SetEtatObjet("BtnCollerInserer", NO).
                                    oongFamilleListe:SetParamFiltreFamille ( glFiltreVisibleFamille ,gcNoeudCourant ).  
                                    oongFamilleListe:Rafraichir( ).

                                END.

                            END.                                               
                        END CASE.

                        THIS-OBJECT:DockPrincipal:ActiveWindow = oToolwindow.

                    END.
                    ELSE 
                    DO:
                        THIS-OBJECT:DockPrincipal:CloseAutoHidePopup().
                        oToolwindow:AutoHideTab:Click:UnSubscribe(THIS-OBJECT:TabStripItem_Click) NO-ERROR.
                        oToolwindow:AutoHideTab:Click:Subscribe(THIS-OBJECT:TabStripItem_Click) NO-ERROR.
                        IF THIS-OBJECT:DockPrincipal:ActiveWindow NE oActiveWindow THEN
                            THIS-OBJECT:DockPrincipal:ActiveWindow = oActiveWindow.
                    END.
                END.
            END.
            ELSE DO:
                MESSAGE 'ERR - TabStripItem_Click '
                VIEW-AS ALERT-BOX.
                RETURN.
            END. 
        END.             
      /*                   
      IF lFlgDocked THEN DO:                      
          //oToolwindow:AutoHideTab:Click:UnSubscribe(THIS-OBJECT:TabStripItem_Click) NO-ERROR.
                           glDockParCode = YES.
                           oToolwindow:DockState=  Telerik.WinControls.UI.Docking.DockState:Docked NO-ERROR.  
                           oToolwindow:Tag = "ON".
                           glDockParCode = NO.
                       //    oToolwindow:AutoHideTab:Click:Subscribe(THIS-OBJECT:TabStripItem_Click) NO-ERROR.
      END.  
      */              
        RETURN.
    END METHOD.

 

                                                                                                                                                                                                                                                                                                                                                                                                           
General Discussions
GridView
Dinko | Tech Support Engineer
Telerik team
 answered on 30 Sep 2025
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Top users last month
Edmond
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fabrizio
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Iron
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Want to show your ninja superpower to fellow developers?
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