I'm getting this exception on a MarkDownTextBlock on .Net Core 3.1 and I suspect the cause would be because I am using .Net core. I do have ModernWpfUi installed and this is how my project looks like

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <UseWPF>true</UseWPF>
    <StartupObject>[...]</StartupObject>
    <ApplicationManifest>app.manifest</ApplicationManifest>
    <Version>1.5.0</Version>
    <Nullable>enable</Nullable>
    <Copyright>[...]</Copyright>
    <Description>[...]</Description>
    <LangVersion>latest</LangVersion>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Humanizer.Core" Version="2.8.26" />
    <PackageReference Include="InputSimulator" Version="1.0.4" />
    <PackageReference Include="Melanchall.DryWetMidi" Version="5.2.0" />
    <PackageReference Include="ModernWpf.Toolkit.UI.Controls.Markdown" Version="0.1.0" />
    <PackageReference Include="ModernWpfUI" Version="0.9.4" />
    <PackageReference Include="PropertyChanged.Fody" Version="3.3.3" />
    <PackageReference Include="Stylet" Version="1.3.6" />
  </ItemGroup>

</Project>

System.IO.FileNotFoundException
  HResult=0x80070002
  Message=Could not load file or assembly 'ModernWpf, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.
  Source=ModernWpf.Toolkit.UI.Controls.Markdown
  StackTrace:
   at ModernWpf.Toolkit.UI.Controls.MarkdownTextBlock.OnLoaded(Object sender, RoutedEventArgs e)
   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 e)
   at System.Windows.BroadcastEventHelper.BroadcastEvent(DependencyObject root, RoutedEvent routedEvent)
   at System.Windows.BroadcastEventHelper.BroadcastLoadedEvent(Object root)
   at MS.Internal.LoadedOrUnloadedOperation.DoWork()
   at System.Windows.Media.MediaContext.FireLoadedPendingCallbacks()
   at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
   at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
   at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   at System.Windows.Threading.DispatcherOperation.InvokeImpl()
   at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
   at MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(Object obj)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at MS.Internal.CulturePreservingExecutionContext.Run(CulturePreservingExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Windows.Threading.DispatcherOperation.Invoke()
   at System.Windows.Threading.Dispatcher.ProcessQueue()
   at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.Run()
   at System.Windows.Application.RunDispatcher(Object ignore)
   at System.Windows.Application.RunInternal(Window window)
   at System.Windows.Application.Run()

Hello there!
Using the MarkdownTextBlock, is there a way to Highlight, Find or Select specific text or region from the rendered text?

Can't find any

Hi Can you port MarkdownTextBlock from WindowsCommunityToolkit to WPF?
https://docs.microsoft.com/en-us/windows/communitytoolkit/controls/markdowntextblock
https://github.com/windows-toolkit/WindowsCommunityToolkit/tree/master/Microsoft.Toolkit.Uwp.UI.Controls.Markdown

Can you add a Property to LinkedClickedEventArgs.cs which store the Clicked Text?

using ModernWpf.Toolkit.UI.Controls;

namespace Test 
{
    public class TestWindow : Window
    {

        private void MarkdownTextBlock_OnLinkClicked(object sender, LinkClickedEventArgs e)
        {
            e.Link // Link behind the clicked Text (Already exists)
            e.ClickedText // New Property which store the clicked Text
        }
    }
}

Issue Description:

FancyZones editor window does not adapt 225% resize mode setting.

Test environment:

OS: Windows 10 Build 21354.1

App version: 0.35.0

App name: Power Toys

Prerequisites:

1. Go to settings > Display settings > Set the resolution to 1280*768.
2. Set the slider value to maximum i.e., 225% (Settings -> Ease of access -> text scaling) and apply.

Repro steps:

1. Launch 'PowerToys' application.
2. Application will get open with default list item 'General' selected.
3. Navigate to 'FancyZones' at the left side of the pane and activate it.
4. Now navigate to 'Launch layout editor' button and activate it.
5. FancyZones editor window will get open.
6. Observe the issue

Actual results:

FancyZones editor window does not adapt 225% resize mode setting.

Expected results:

FancyZones editor window should adapt 225% resize mode setting.

Attachments:

for example, can i get a help for the use of add a picture?

Hi!

Really great to see someone back-porting some Windows Community Toolkit code to WPF!

However, I noticed some of the license notices have been stripped from the code copied over (or maybe it's not clear which ones are unique to this project to call out your own license). You still need to preserve the headers for files from the WCT and preserve the copyright within the license:

Copyright (c) .NET Foundation and Contributors
All rights reserved.

Either calling it out in your license file at the top with your name or using a third-party notice file with a copy of our license.

Thanks!

Description:
If Screen reader users are not aware that an error has occurred, they will not be able to determine what is wrong before encountering the error indicator, thinking that the page simply is not functional.

Test Environment:
OS: Windows 11 Build 22000.978
App version: v0.62.1
App name: Power Toys

AT (include version number):
Narrator

Repro Steps:

1. Launch 'Power Toys' application.
2. Turn on the Narrator.
3. Application will get open with default list item 'General' selected.
4. Navigate to 'Fancy Zones' at the left side of the pane and activate it.
5. Now navigate to 'Launch layout editor button and activate it.
6. Fancy Zones editor window will get open.
7. Navigate to 'Edit layout' button of any layout (say Grid) under Templates and activate it.
8. Edit layout dialog gets open.
9. Navigate to the 'Space around zones' edit field and enter the value greater than 1000 say 1500 and press 'Tab key.
10. Observe the issue.

Actual Result:
Error message doesn't get identified for the edit fields of edit layout dialog by entering value other than its defined range.
Entering value greater than 1000 say '1500' and pressing tab key, value automatically gets change to 1000.
Also, narrator does not announce the minimum and the maximum value of the edit field when focus navigates there.

Expected Result:
Error message should get identified for the edit fields of edit layout dialog by entering value other than its defined range.
Entering value greater than 1000 say '1500' error message should get displayed on the screen such as "Value greater than 1000 not allowed".
Also, narrator should announce the minimum and the maximum value of the edit field when focus navigates there.

Additional Notes:
Same happens with 'Number of zones'. It automatically gets change to 128, whenever we try to enter value more than 128.

Attachment:
https://user-images.githubusercontent.com/93735775/194355981-1358b5fd-3dd2-4b45-b866-7dd9007800bc.mp4

When using MarkDownTextBlock in a DataTemplate of a ListBox and turning on virtualization on that ListBox, eventually MarkdownTextBlock keeps throws the exception "System.ArgumentException: An item with the same key has already been added":

StackTrace is:

   at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
   at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   at ModernWpf.Toolkit.UI.Extensions.DependencyObjectExtensions.RegisterPropertyChangedCallback(DependencyObject dependencyObject, DependencyProperty dependencyProperty, DependencyPropertyChangedCallback callback)
   at ModernWpf.Toolkit.UI.Controls.MarkdownTextBlock.OnLoaded(Object sender, RoutedEventArgs e)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.BroadcastEventHelper.BroadcastEvent(DependencyObject root, RoutedEvent routedEvent)
   at System.Windows.BroadcastEventHelper.BroadcastLoadedEvent(Object root)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)    at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
   at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   at ModernWpf.Toolkit.UI.Extensions.DependencyObjectExtensions.RegisterPropertyChangedCallback(DependencyObject dependencyObject, DependencyProperty dependencyProperty, DependencyPropertyChangedCallback callback)
   at ModernWpf.Toolkit.UI.Controls.MarkdownTextBlock.OnLoaded(Object sender, RoutedEventArgs e)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.BroadcastEventHelper.BroadcastEvent(DependencyObject root, RoutedEvent routedEvent)
   at System.Windows.BroadcastEventHelper.BroadcastLoadedEvent(Object root)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

Reason for this is that the control registers property change callbacks via DependencyObjectExtensions.RegisterPropertyChangedCallback inside a

Dictionary<long, (DependencyPropertyDescriptor Descriptor, EventHandler Handler)> descriptors

where the key is always descriptors.Count + 1.

When using virtualization MarkDownTextBlocks are dynamically loaded and unloaded while scrolling. Unloading a MarkDownTextBlock calls DependencyObjectExtensions.UnregisterPropertyChangedCallback which removes certain keys from that dictionary.
When calling then DependencyObjectExtensions.RegisterPropertyChangedCallback again, descriptors.Count + 1 might return a key that is already used in the dictionary.

Solution:
A better algorithm for creating a unique key is needed. Suggestion: Guid.New()