Type in Japanese text in RichTextBox that word wraps beyond the first line and export it to PDF. The text should always be left aligned (as visually shown when typing) but has an "indent" when exported when the font is Segoe UI.
The operating system region and language needs to be set to Japanese.
RichTextBox seems to have several issues with Japanese, but being locked from visibility or edit is the biggest one.
To recreate, start typing in Japanese, push the "right" arrow after selecting the IME option desired, then hit "spacebar." This seems to duplicate the text, then when trying to continue to type into the text field the text is no longer visible (yet the IME does display).
The native WPF RichTextBox has no issues (and also supports partial selection, etc.).
I've attached a video to show the behavior with 2025 Q1 telerik.
*note:* This is on a machine with NVIDIA graphics. I mention this as there may be some issues with RichTextBox and the hardware... When I'm in a virtual machine with a completely Japanese environment and virtual graphics driver, there is NO text visible at all when trying to type into the RichTextBox. Works fine with other controls and wpf RichTextBox.
It seems that the first time a Center TextAlignment is applied to the selection, its length is cached. Because of this, when the selection content (text) changes the length is not updated, thus the text doesn't align properly. It aligns accord to the initial length of the context. The content doesn't update also if the alignment is reset.
To work this around, avoid the FlowNoWrap layout mode and use only Flow.
NullReferenceException is thrown when the document gets updated after TableRow objects were removed with the Remove method of the parent Rows collection of the Table.
The table.Rows.Remove method is not properly removing some of the rows.
Stacktrace:
Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Model.TableGridMeasurer.CalculateTableCellMinMaxWidths(Telerik.Windows.Documents.Model.TableCell cell, float availableWidth) Line 137 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Model.TableGridMeasurer.CalculateTableMinMaxWidths(Telerik.Windows.Documents.Model.Table table, float availableWidth) Line 165 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Model.TableGridMeasurer.MeasureAutoFit(Telerik.Windows.Documents.Model.Table table, float availableWidth) Line 229 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Model.Table.RecalculateColumnWidths(float measureWidth) Line 1151 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Model.Table.RecalculateTableGrid(float measureWidth) Line 1249 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Layout.TableLayoutBox.MeasureOverride(Telerik.Windows.Documents.Model.SizeF availableSize) Line 265 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Layout.LayoutElement.MeasureCore(Telerik.Windows.Documents.Model.SizeF availableSize) Line 933 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Layout.LayoutElement.Measure(Telerik.Windows.Documents.Model.SizeF availableSize) Line 836 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Layout.SectionLayoutBox.MeasureOverrideInternal(Telerik.Windows.Documents.Model.SizeF availableSize) Line 721 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Layout.SectionLayoutBox.MeasureOverride(Telerik.Windows.Documents.Model.SizeF availableSize) Line 468 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Layout.LayoutElement.MeasureCore(Telerik.Windows.Documents.Model.SizeF availableSize) Line 933 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Layout.LayoutElement.Measure(Telerik.Windows.Documents.Model.SizeF availableSize) Line 836 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Layout.DocumentLayoutBox.MeasureOverrideInternal(Telerik.Windows.Documents.Model.SizeF availableSize) Line 223 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Layout.DocumentLayoutBox.MeasureOverride(Telerik.Windows.Documents.Model.SizeF availableSize) Line 150 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Layout.LayoutElement.MeasureCore(Telerik.Windows.Documents.Model.SizeF availableSize) Line 933 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Layout.LayoutElement.Measure(Telerik.Windows.Documents.Model.SizeF availableSize) Line 836 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.Model.RadDocument.Measure(Telerik.Windows.Documents.Model.SizeF measureSize) Line 1515 C# Telerik.Windows.Documents.dll!Telerik.Windows.Documents.UI.DocumentPrintLayoutPresenter.MeasureOverride(System.Windows.Size availableSize) Line 714 C#
To work this around, use the DeleteTableRow method of the RadDocumentEditor.
RadDocumentEditor documentEditor = new RadDocumentEditor(document); documentEditor.DeleteTableRow(row);
The issue reproduces when track changes is enabled and new text is entered. After waiting some time and pressing the Backspace on the keyboard in order to delete a character, nothing happens. You should press the Backspace a second time in order to make the deletion work. After that you can delete the content normally.
The waiting time before pressing the Backspace is usually until the next minute of the clock comes. For example, you can write something at 14:55 and wait until 14:56. Then, press Backspace.
If you check the Output pane of Visual Studio you will see the following assertion failure message printed:
---- DEBUG ASSERTION FAILED ---- at Telerik.Windows.Documents.Model.RadDocumentEditor.DeleteTrackChanges(Boolean deletePrevious) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\Model\RadDocumentEditor_Editing.cs:line 693 at Telerik.Windows.Documents.Model.RadDocumentEditor.Delete(Boolean deletePrevious) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\Model\RadDocumentEditor_Editing.cs:line 85 at Telerik.Windows.Controls.RadRichTextBox.Telerik.Windows.Documents.Model.IDocumentEditor.Delete(Boolean deletePrevious) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\UI\RadRichTextBox.cs:line 4890 at Telerik.Windows.Controls.RadRichTextBox.Delete(Boolean deletePrevious) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\UI\RadRichTextBox.cs:line 4866 at Telerik.Windows.Documents.RichTextBoxCommands.DeleteCommand.ExecuteOverride(Object parameter) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\RichTextBoxCommands\DeleteCommand.cs:line 57 at Telerik.Windows.Documents.RichTextBoxCommands.RichTextBoxCommandBase.Execute(Object parameter, Boolean focusCaret) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\RichTextBoxCommands\RichTextBoxCommandBase.cs:line 316 at Telerik.Windows.Documents.RichTextBoxCommands.RichTextBoxCommandBase.Execute(Object parameter) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\RichTextBoxCommands\RichTextBoxCommandBase.cs:line 285 at Telerik.Windows.Documents.RichTextBoxCommands.RichTextBoxRoutedCommand.Execute(Object parameter, RadRichTextBox radRichTextBox) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\RichTextBoxCommands\RoutedCommands\RichTextBoxRoutedCommand.cs:line 57 at Telerik.Windows.Documents.RichTextBoxCommands.RichTextBoxRoutedCommand.CommandBindingHelper.CommandBinding_Executed(Object sender, ExecutedRoutedEventArgs e) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\RichTextBoxCommands\RoutedCommands\RichTextBoxRoutedCommand.cs:line 17 at System.Windows.Input.CommandBinding.OnExecuted(Object sender, ExecutedRoutedEventArgs e) at System.Windows.Input.CommandManager.FindCommandBinding(Object sender, RoutedEventArgs e, ICommand command, Boolean execute) at System.Windows.Input.CommandManager.OnExecuted(Object sender, ExecutedRoutedEventArgs e) at System.Windows.UIElement.OnExecutedThunk(Object sender, ExecutedRoutedEventArgs e) at System.Windows.Input.ExecutedRoutedEventArgs.InvokeEventHandler(Delegate genericHandler, Object target) at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target) at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted) at System.Windows.Input.RoutedCommand.ExecuteImpl(Object parameter, IInputElement target, Boolean userInitiated) at System.Windows.Input.RoutedCommand.Execute(Object parameter, IInputElement target) at System.Windows.Input.RoutedCommand.System.Windows.Input.ICommand.Execute(Object parameter) at Telerik.Windows.Documents.UI.Extensibility.DefaultInputHandler.HandleInput(RadRichTextBox richTextBox, PreviewEditorKeyEventArgs e) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\RichTextBoxCommands\RoutedCommands\DefaultInputHandler.cs:line 54 at Telerik.Windows.Controls.RadRichTextBox.HandlePresenterKeyDown(PreviewEditorKeyEventArgs e) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\UI\RadRichTextBox.cs:line 4612 at Telerik.Windows.Documents.UI.DocumentPresenterBase.HandleKeyDown(KeyEventArgs e) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\UI\DocumentPresenterBase.cs:line 859 at Telerik.Windows.Documents.UI.DocumentPresenterBase.OnPreviewKeyDown(KeyEventArgs e) in C:\PersonalFiles\Git\wpf\Controls\RichTextBox\Core\UI\DocumentPresenterBase.cs:line 805
When the exported document contains a very precise indent values, these are saved using scientific notation, which is unsupported in MS Word. Opening the file in Word results in the following error: "Word experienced an error trying to open the file."
Here is an example of the troublesome setting in the body of the produced document:
<w:ind w:firstLine="6.420405952667352E-06" w:left="76.53543090820312" w:right="0" />
To work this around, you can open the exported document with the WordsProcessing library. This will give you a RadFlowDocument object which then can be exported to a file again. This will save the indent values properly in the new document.
var dplProvider = new Telerik.Windows.Documents.Flow.FormatProviders.Docx.DocxFormatProvider();
using (var inputStream = File.OpenRead("../../../originalFile.docx"))
{
Telerik.Windows.Documents.Flow.Model.RadFlowDocument flowDoc = dplProvider.Import(inputStream, TimeSpan.FromSeconds(5));
using (var outputStream = File.OpenWrite("../../../convertedFile.docx"))
{
dplProvider.Export(flowDoc, outputStream, TimeSpan.FromSeconds(5));
}
}
Or if you use the RichTextBox document model only to create documents in code (without using the RadRichTextBox control), you can replace the code with the WordsProcessing API.
A SocketException can occur when the ImageInline source is assigned to a link pointing to a picture on a remote server (a website). For example: UriSource ="https://docs.telerik.com/devtools/wpf/knowledge-base/images/kb-chartview-categorical-and-datetime-axis-0.png"
This could happen during the fetching of the image stream. In some cases, the server may give a NetworkStream or ConnectionStream, or similar Stream implementation, which keeps an open connection between the application and the server. If the connection get severed during the stream reading, an exception is thrown.
The exception message is: "Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host."
The stacktrace is:
Exception Info: System.Net.Sockets.SocketException
at System.Net.Sockets.NetworkStream.Read(Byte[], Int32, Int32)
Inner Exception:
Exception Info: System.IO.IOException
at System.Net.ConnectStream.Read(Byte[], Int32, Int32)
at System.IO.Stream.InternalCopyTo(System.IO.Stream, Int32)
at Telerik.Windows.Documents.Layout.ExtensionMethods.ToMemoryStream(System.IO.Stream)
at Telerik.Windows.Documents.Model.ImageInline.<SetStreamFromUriSource>b__0(System.Object, StreamReadyEventArgs)
at Telerik.Windows.Documents.Utils.ResourceStreamLocator.OnStreamReady()
at System.Net.WebClient.OnOpenReadCompleted(System.Net.OpenReadCompletedEventArgs)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)
at System.Windows.Threading.DispatcherOperation.InvokeImpl()
at MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(System.Object)
at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
at MS.Internal.CulturePreservingExecutionContext.Run(MS.Internal.CulturePreservingExecutionContext, System.Threading.ContextCallback, System.Object)
at System.Windows.Threading.DispatcherOperation.Invoke()
at System.Windows.Threading.Dispatcher.ProcessQueue()
at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)
at MS.Win32.HwndWrapper.WndProc(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)
at MS.Win32.HwndSubclass.DispatcherCallbackOperation(System.Object)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)
at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(System.Windows.Threading.DispatcherPriority, System.TimeSpan, System.Delegate, System.Object, Int32)
at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr, Int32, IntPtr, IntPtr)
at MS.Win32.UnsafeNativeMethods.DispatchMessage(System.Windows.Interop.MSG ByRef)
at System.Windows.Threading.Dispatcher.PushFrameImpl(System.Windows.Threading.DispatcherFrame)
at System.Windows.Application.RunDispatcher(System.Object)
at System.Windows.Application.RunInternal(System.Windows.Window)