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();
}

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. 

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.

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

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.

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

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

When the RadForm is used as MDI Child hosted by RadDock, the rendering of the form is not appropriate.

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.

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;
}

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

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.

To reproduce:
  radTreeView1.Filter = "new";
            radTreeView1.Nodes.Add("new Node");
            for (int i = 0; i < 1000; i++)
            {
                radTreeView1.Nodes.Add(new RadTreeNode("test"));
            }

Workaround:
            radTreeView1.TreeViewElement.Update(RadTreeViewElement.UpdateActions.Reset);

To reproduce:
public Form1()
{
    InitializeComponent();

    this.radTextBox1.Text = "abcd";
    this.radTextBox2.Text = "abcd";
    this.radTextBoxControl1.Text = "abcd";
    this.radTextBoxControl2.Text = "abcd";

    this.radTextBox2.Multiline = true;
    this.radTextBoxControl2.Multiline = true;

    this.textBox1.Text= "abcd";
    this.textBox2.Text= "abcd";
    this.textBox2.Multiline = true;
}

Workaround: set the Multiline property to true in the Form.Load event.

Second workaround: this.radTextBox2.TextBoxElement.TextBoxItem.Margin = new Padding(-2, 0, 0, 0);

To reproduce:
this.radTextBoxControl1.Text = "dog and blue glue";
this.radTextBoxControl1.Size = new Size(50, 65);
this.radTextBoxControl1.Multiline = true;

Workaround:
use RadTextBox.

1. Add RadDropDowlList in form. 
2. Open the items collection and add some items. 
3. After that set the Selected property of one item to true and click OK. 
4. You will see that the change is not saved.

Workaround: 
Set the selected item at run time.

(This request may be specific to VS solutions which produce only DLLs, and not to ones which create a .exe.)

At the moment, the default behaviour for everything else in my VS project is to not produce warnings unless something might be wrong, which I may need to action.

WinForms,as of the latest release (2025) is the only thing which produces warning messages where there is not problem, which is not very tidy. I only want to see things in the build output which need my attention, defintely not 'happy' messages, or warnings which are not needed.

Currently, for each project in my solution, I get a message like:

1>  [Telerik and Kendo UI Licensing]
1>        Valid Telerik UI for WinForms license found. Make sure the main application also references Telerik.Licensing when using a class library.

...but I have a valid licence, and everything is OK. No action is needed.

Your support suggested adding...

  <TelerikLicensingVerbosity>quiet</TelerikLicensingVerbosity>

...to each project in my solution, but that still produces the above build message.

A polite solution would be to turn-off ALL such warning messages, and let me switch them ON when needed. Preferably via a setting somewhere, not by editing the VS project file, which means unloading, editing the project file, and realoading each of many  projects.

(Visual Studio 2026, not currently an option in the drop-down below)

Contrary to Telerik.WinControls.UI.Barcode.QRCode, Telerik.WinControls.UI.Barcode.Symbology.QRCode creates invalid (unscannable) QR-Codes if the message contains umlauts when using ECIMode.UTF8.

 

We are using Symbology.QRCode, because we use it in columns of a RadGridView.

I've attached two example QR-Codes of the value "Bär", one using Barcode.QRCode, and the other one using Barcode.Symbology.QRCode.

Note: I have one scanner that can scan some of the Barcode.Symbology QR-Codes with umlauts.

System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.PdfElementToFixedElementTranslator.CreateFormField(PdfContentManager contentManager, FormFieldNodeOld terminalFormField)
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.PdfElementToFixedElementTranslator.CreateWidgetAnnotation(WidgetOld source, PdfFormatProvider provider)
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.PdfElementToFixedElementTranslator.CreateAnnotation(AnnotationOld source, PdfFormatProvider provider)
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Pdf.PdfFormatProvider.CopyAnnotationsFromPageSource(PageOld source, AnnotationCollection annotations)
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Pdf.PdfFormatProvider.LoadPageAnnotations(RadFixedPage page)
   at Telerik.Windows.Pdf.Documents.Fixed.Model.RadFixedPage.LoadAnnotations()
   at Telerik.Windows.Pdf.Documents.Fixed.Model.Internal.RadFixedPageInternal.Arrange()
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.PdfReader.PageContentLoader.Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.PdfReader.IPageContentLoader.LoadPageContent(RadFixedPage page)
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.PdfReader.PagesCacheManager.BeginUsingPageContent(RadFixedPage page)
   at Telerik.WinControls.UI.RadFixedPageElement.Attach(RadFixedPage data, Object context)
   at Telerik.WinControls.UI.RadFixedPageElement..ctor(RadFixedPage page, RadPdfViewerElement owner)
   at Telerik.WinControls.UI.RadPdfViewerElement.CreatePageElement(RadFixedPage data, Object context)
   at Telerik.WinControls.UI.FixedPageElementProvider.CreateElement(RadFixedPage data, Object context)
   at Telerik.WinControls.UI.BaseVirtualizedElementProvider`1.GetElement(T data, Object context)
   at Telerik.WinControls.UI.BaseVirtualizedContainer`1.UpdateElement(Int32 position, T data)
   at Telerik.WinControls.UI.BaseVirtualizedContainer`1.MeasureElements()
   at Telerik.WinControls.PdfViewer.PdfViewerStackContainer.MeasureElements()
   at Telerik.WinControls.UI.BaseVirtualizedContainer`1.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
   at Telerik.WinControls.RadElement.Measure(SizeF availableSize)
   at Telerik.WinControls.UI.ScrollViewElement`1.MeasureViewElement(SizeF availableSize)
   at Telerik.WinControls.UI.ScrollViewElement`1.MeasureView(SizeF availableSize)
   at Telerik.WinControls.UI.ScrollViewElement`1.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.UI.VirtualizedScrollPanel`2.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.UI.RadPdfViewerElement.MeasureOverride(SizeF availableSize)
   at Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize)
   at Telerik.WinControls.RadElement.Measure(SizeF availableSize)
   at Telerik.WinControls.Layouts.ContextLayoutManager.UpdateLayout()
   at Telerik.WinControls.Layouts.ContextLayoutManager.UpdateLayoutCallback(ILayoutManager manager)