In Development
Last Updated: 01 Apr 2026 15:30 by ADMIN
Scheduled for 2026 Q2 (May)

In this specific scenario, we have a menu with 2 menu items: &File and &Open. The mnemonic sign is set to the F and O letters. In the form, we have a TextBox control which is currently focused. The next step is to press the Alt key while the TextBox is focused. Pressing some other letter, D for example, the letter will be typed in the TextBox. This letter does not exist as a mnemonic, and the RadMenu will ignore it. The RadMenu remains in active mnemonic state.

Expected behavior: Using none mnemonic letter should not be accepted by any other control until this state is closed in the RadMenu.


In Development
Last Updated: 01 Apr 2026 14:52 by ADMIN
Scheduled for 2026 Q2 (May)

Hello, 

we are trying to use RadPropertyGrid to show the properties of some objects listed in a RadGrdiView. 

We use ExpandableObject to expand our custom property, but we have some problems when we try to show the properties of multiple selected items, when the values of the attribute of the property are not the same in all the selected objects. We tried to use PropertyGrid of Winform and we don't have this problem. 

Thank you.

In Development
Last Updated: 01 Apr 2026 14:35 by ADMIN
Scheduled for 2026 Q2 (May)
In this particular scenario, we double-click a property grid item. Then we try to resize the description area at the bottom. When we resize the area and release the mouse left button, the area continue to resize while mouse is moved.
In Development
Last Updated: 01 Apr 2026 13:36 by ADMIN
Scheduled for 2026 Q2 (May)
Workaround:

public class CustomRadDropDownList : RadDropDownList
{
    protected override RadDropDownListElement CreateDropDownListElement()
    {
        return new CustomRadDropDownListElement();
    }

    public override string ThemeClassName  
    { 
        get 
        { 
            return typeof(RadDropDownList).FullName;  
        }
    }
}

public class CustomRadDropDownListElement : RadDropDownListElement
{
    protected override RadDropDownListArrowButtonElement CreateArrowButtonElement()
    {
        return new CustomRadDropDownListArrowButtonElement();
    }

    protected override Type ThemeEffectiveType     
    { 
        get    
        { 
            return typeof(RadDropDownListElement);     
        }
    }
}

public class CustomRadDropDownListArrowButtonElement : RadDropDownListArrowButtonElement
{
    protected override Type ThemeEffectiveType     
    { 
        get    
        { 
            return typeof(RadDropDownListArrowButtonElement);     
        }
    }
    
    protected override void OnClick(EventArgs e)
    {
        MouseEventArgs args = e as MouseEventArgs;
        if (args.Button == System.Windows.Forms.MouseButtons.Left)
        {
            base.OnClick(e);
        }
    }
}
In Development
Last Updated: 01 Apr 2026 12:48 by ADMIN
Scheduled for 2026 Q2 (May)
The issue exists with RadMenuItem as well!

Workaround:

public class CustomCommandBarButton : CommandBarButton
{
    protected override void OnClick(EventArgs e)
    {
        MouseEventArgs args = e as MouseEventArgs;
        if (args.Button == System.Windows.Forms.MouseButtons.Left)
        {
            base.OnClick(e);
        }
    }

    protected override Type ThemeEffectiveType     
    { 
        get    
        { 
            return typeof(CommandBarButton);     
        }
    }
}
Declined
Last Updated: 31 Mar 2026 10:35 by ADMIN
When you focus a RadTextBox you will notice the keyboard button that popups next to the focused control. However, for the RadAutoCompleteBox this keyboard button does not show.

Workaround: show it manually on the GotFocus event and hide it on the LostFocus event 

private void radTextBox1_GotFocus(object sender, EventArgs e)
{
    string progFiles = @"C:\Program Files\Common Files\Microsoft Shared\ink";
    string keyboardPath = Path.Combine(progFiles, "TabTip.exe");
    Process.Start(keyboardPath);
}
 
private void radTextBox1_LostFocus(object sender, EventArgs e)
{
    var procs = Process.GetProcessesByName("TabTip");
    if (procs.Length != 0)
        procs[0].Kill();
}
Completed
Last Updated: 31 Mar 2026 09:37 by ADMIN
To reproduce:

private void Form1_Load(object sender, EventArgs e)
        {
            this.categoriesTableAdapter.Fill(this.nwindDataSet.Categories);

            this.radMultiColumnComboBox1.DataSource = this.categoriesBindingSource;
            this.radMultiColumnComboBox1.DisplayMember = "CategoryName";
            this.radMultiColumnComboBox1.ValueMember = "CategoryID";

            this.radMultiColumnComboBox1.EditorControl.EnableFiltering = true;
            this.radMultiColumnComboBox1.EditorControl.ShowHeaderCellButtons = true;
        }

Workaround:

 public Form1()
 {
     InitializeComponent();
     this.radMultiColumnComboBox1.MultiColumnComboBoxElement.PopupClosing += MultiColumnComboBoxElement_PopupClosing;
     this.radMultiColumnComboBox1.EditorControl.FilterPopupInitialized += EditorControl_FilterPopupInitialized;
 }

 private void EditorControl_FilterPopupInitialized(object sender, FilterPopupInitializedEventArgs e)
 {
     RadListFilterPopup filterPopup = e.FilterPopup as RadListFilterPopup;
     if (filterPopup != null)
     {
         filterPopup.PopupOpened -= filterPopup_PopupOpened;
         filterPopup.PopupOpened += filterPopup_PopupOpened;
         filterPopup.PopupClosed -= filterPopup_PopupClosed;
         filterPopup.PopupClosed += filterPopup_PopupClosed;
     }
 }

 bool shouldCancel = false;

 private void filterPopup_PopupClosed(object sender, RadPopupClosedEventArgs args)
 {
     shouldCancel = false;
 }

 private void filterPopup_PopupOpened(object sender, EventArgs args)
 {
     shouldCancel = true;
 }

 private void MultiColumnComboBoxElement_PopupClosing(object sender, RadPopupClosingEventArgs args)
 {
     args.Cancel = shouldCancel;
 }
Declined
Last Updated: 27 Mar 2026 13:19 by ADMIN
When I select items 1 through 4 in the drop-down list, the expected event occurs (the selected item is removed from the drop-down list and added to the list view).  When I select the last item in the list (item 5), the item is added to the list and then I get the ArgumentOutOfRangeException. 
Declined
Last Updated: 25 Mar 2026 12:19 by ADMIN
RadDropDownList - There is an empty line at the bottom of drop down list if you close drop down by arrow button.

Steps to reproduce :

Creating the application:

    New > Project > RadControls Windows Forms Application
    A wizard appears; the RadControls for Winforms version is selected (InstallFolder, not GAC)
    No components nor Themes were selected
    Code changed from:

public partial class Form1 : Form
to
public partial class Form1 : RadForm
The application consisted of a single drop down on the RadForm.The drop down DropDownStyle property changed to "DropDownList". The drop down had enough items to cause the scrollbar to occur.
No other properties from either form or drop down were changed.

The attached errorsteps.png are split into the following steps:

    Application opened
    Scroll down to the last item
    Select the item
    Open the drop down and scroll back to the top of the list; click the down arrow button to close the drop down
    Open the drop again.
Declined
Last Updated: 25 Mar 2026 12:10 by ADMIN
FIX. RadContextMenu/RadMenu - animations does not perform correctly on Windows 8

WORKAROUND

Execute ThemeResolutionService.AllowAnimations = false; before the context menu is opened and then Allow animations again when the context menu is closed
Unplanned
Last Updated: 25 Mar 2026 10:55 by ADMIN

The AccessibleName property is not respected by the Windows Narrator.

Other controls that have the same behavior:

  • RadDropDownList
  • RadMaskedEditBox
  • RadDateTimePicker
Declined
Last Updated: 23 Mar 2026 13:58 by ADMIN
Under specific circumstances and in Windows 2008 Server environment the RadTabStrip internally used in RadDock does not get a proper size.

Workaround:
bool performLayout = false;
  
protected override void OnSizeChanged(EventArgs e)
{
    base.OnSizeChanged(e);
  
    if (this.WindowState == FormWindowState.Minimized)
    {
        this.performLayout = true;
    }
  
    else if (this.performLayout)
    {
        //reset padding to force bounds update
        this.Padding = new Padding(1);
        this.Padding = Padding.Empty;
        this.performLayout = false;
    }
}

Basically, you need to override the OnSizeChanged method of the main form and first set and then reset its Padding when the it goes from Minimized to another state. This will trigger that internal layout mechanisms of our controls and you will get the RadGridView shown as expected.
Declined
Last Updated: 23 Mar 2026 13:56 by ADMIN
The size of RadForm under Windows XP is incorrect when its initial state as MDI child is Maximized and after that the state is changed to Normal.

Workaround:
Imports Telerik.WinControls.UI

Public Class BaseRadForm
    Inherits RadForm 

    Private Shared LastWindowState As FormWindowState = FormWindowState.Normal
    Private Shared suspendClientSizeChangedFlag As Boolean = False
 
    Protected Overrides Sub OnResizeBegin(ByVal e As System.EventArgs)
        Me.MaximumSize = New Size(0, 0)
        MyBase.OnResizeBegin(e) 
    End Sub
     
    Protected Overrides Sub OnActivated(ByVal e As System.EventArgs)
        Me.MaximumSize = New Size(0, 0)
        MyBase.OnActivated(e)
    End Sub

    Protected Overrides Sub OnDeactivate(ByVal e As System.EventArgs)
        Me.MaximumSize = New Size(0, 0)
        MyBase.OnDeactivate(e)
    End Sub

    Protected Overrides Sub OnClientSizeChanged(ByVal e As System.EventArgs)
        Dim osInfo As System.OperatingSystem = System.Environment.OSVersion
        If (suspendClientSizeChangedFlag OrElse osInfo.Version.Major >= 6) Then
            Return
        End If

        If Not LastWindowState.Equals(Me.WindowState) Then
            LastWindowState = Me.WindowState
            If Me.WindowState.Equals(FormWindowState.Normal) Then
                suspendClientSizeChangedFlag = True
                Me.MaximumSize = New Size(500, 500)
                suspendClientSizeChangedFlag = False
            ElseIf Me.WindowState.Equals(FormWindowState.Maximized) Then
                Me.MaximumSize = New Size(0, 0)
            End If
        Else
            Me.MaximumSize = New Size(0, 0)
        End If

        MyBase.OnClientSizeChanged(e)

    End Sub


End Class
Declined
Last Updated: 23 Mar 2026 13:11 by ADMIN
If you fill a WrapLayoutPanel with some content and set it to the ViewPort property of the RadScrollViewer, you will notice that RadScrollViewer will not scroll the panel correctly.

Workaround: http://www.telerik.com/forums/scrolling-using-wraplayoutpanel#yirv_YCJAESwbvexlHks8Q
Declined
Last Updated: 23 Mar 2026 13:07 by ADMIN
When the RadForm is used as MDI Child hosted by RadDock, the rendering of the form is not appropriate.
Declined
Last Updated: 23 Mar 2026 12:49 by ADMIN
When Windows aero effects are enabled and the form width is being decreased, the title bar text appears over the title bar buttons and further more when continuing reducing the width of the form the buttons disappear and a small black rectangle is shown instead.
In Development
Last Updated: 19 Mar 2026 12:02 by ADMIN
RadSplitButton does not get a focus rectangle when focus by the Tab key. One should first click the action part and then the focus rectangle will appear..

The current workaround is:
public class MyRadSplitButton : RadSplitButton 
{ 
    protected override void OnEnter(EventArgs e) 
    { 
        base.OnEnter(e); 
  
        this.DropDownButtonElement.ActionButton.Focus(); 
    } 
}
Declined
Last Updated: 17 Mar 2026 14:01 by ADMIN
ADMIN
Created by: Stefan
Comments: 1
Category: Form
Type: Bug Report
2
To reproduce:
- Add four buttons to a RadForm
- On each button click use ThemeResolutionService to change the theme
=> the form size increases in height

Workaround:
Set the MaximumSize of the form to the current form size prior changing the theme and then remove this setting:
private void radButton1_Click(object sender, EventArgs e)
{
    this.MaximumSize = this.Size; ;
    ThemeResolutionService.ApplicationThemeName = "Office2010Blue";
    this.MaximumSize = Size.Empty;
}
Declined
Last Updated: 13 Mar 2026 14:05 by ADMIN
To reproduce:


Add nodes to RadTreeView with at least 3 levels hierarchy. Set some of the last level nodes Visible property to false. Start the application. Expand some nodes and scroll. You will notice that the last item will change sometimes.


Workaround:
Set this.radTreeView1.TreeViewElement.AllowArbitraryItemHeight = true;
Use ItemHeight = 1, instead of Visible = false
Declined
Last Updated: 13 Mar 2026 13:51 by ADMIN
The Enabled property cannot be set in PropertyBuild if the RadTreeView is already data-binded via Property builder

Workaround:

Set the property at run-time.
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