From 89c79d1cb5a575ad0caaadd8fa55b8576c80d253 Mon Sep 17 00:00:00 2001
From: Lex Li <support@lextm.com>
Date: Tue, 12 May 2026 23:23:20 -0400
Subject: [PATCH 1/2] Switch to a single rich text block

---
 .../Visitors/NativeMarkdownVisitor.cs         | 62 ++++++++++++++-----
 1 file changed, 47 insertions(+), 15 deletions(-)

diff --git a/src/WinUI.Markdown/Visitors/NativeMarkdownVisitor.cs b/src/WinUI.Markdown/Visitors/NativeMarkdownVisitor.cs
index 4f4d9ea..6bd07db 100644
--- a/src/WinUI.Markdown/Visitors/NativeMarkdownVisitor.cs
+++ b/src/WinUI.Markdown/Visitors/NativeMarkdownVisitor.cs
@@ -34,11 +34,13 @@ public NativeMarkdownVisitor(MarkdownTheme theme)
 
     public FrameworkElement Render(MarkdownDocument document)
     {
-        var root = CreateStackPanel();
+        var root = CreateRichTextBlock();
+        root.IsTextSelectionEnabled = true;
+
         var blockIndex = 0;
         foreach (var block in document)
         {
-            root.Children.Add(RenderBlock(block, 0, blockIndex == 0));
+            AddRenderedBlock(root.Blocks, RenderBlock(block, 0, blockIndex == 0));
             blockIndex++;
         }
 
@@ -50,6 +52,38 @@ public FrameworkElement Render(MarkdownDocument document)
         };
     }
 
+    private void AddRenderedBlock(BlockCollection target, FrameworkElement element)
+    {
+        if (element is RichTextBlock richTextBlock)
+        {
+            while (richTextBlock.Blocks.Count > 0)
+            {
+                var block = richTextBlock.Blocks[0];
+                richTextBlock.Blocks.RemoveAt(0);
+                target.Add(block);
+            }
+
+            return;
+        }
+
+        RenderUiBlock(target, element);
+    }
+
+    private static void RenderUiBlock(BlockCollection target, UIElement child)
+    {
+        target.Add(new Paragraph
+        {
+            Margin = new Thickness(0),
+            Inlines =
+            {
+                new InlineUIContainer
+                {
+                    Child = child
+                }
+            }
+        });
+    }
+
     private FrameworkElement RenderBlock(MarkdigBlock block, int nestingLevel, bool isFirstInContainer = false)
     {
         return block switch
@@ -75,21 +109,19 @@ private FrameworkElement RenderHeading(HeadingBlock heading, bool isFirstInConta
         var sizeIndex = Math.Clamp(heading.Level - 1, 0, 5);
         var fontSize = HeadingSize(sizeIndex);
         var borderThickness = HeadingBorderThickness(sizeIndex);
-        var textBlock = new TextBlock
-        {
-            Text = InlineText(heading.Inline),
-            FontFamily = _theme.BodyFont,
-            FontSize = fontSize,
-            FontWeight = HeadingWeight(sizeIndex),
-            LineHeight = fontSize * 1.25,
-            TextWrapping = TextWrapping.WrapWholeWords,
-            Foreground = _theme.Foreground
-        };
+        var block = CreateRichTextBlock();
+        block.Margin = new Thickness(0, isFirstInContainer ? 0 : _theme.HeadingSpacingBefore, 0, _theme.HeadingSpacingAfter);
+        block.FontSize = fontSize;
+        block.FontWeight = HeadingWeight(sizeIndex);
+        block.LineHeight = fontSize * 1.25;
+
+        var paragraph = new Paragraph();
+        AppendInlines(paragraph.Inlines, heading.Inline);
+        block.Blocks.Add(paragraph);
 
         if (borderThickness <= 0)
         {
-            textBlock.Margin = new Thickness(0, isFirstInContainer ? 0 : _theme.HeadingSpacingBefore, 0, _theme.HeadingSpacingAfter);
-            return textBlock;
+            return block;
         }
 
         return new Border
@@ -98,7 +130,7 @@ private FrameworkElement RenderHeading(HeadingBlock heading, bool isFirstInConta
             BorderThickness = new Thickness(0, 0, 0, borderThickness),
             Padding = new Thickness(0, 0, 0, fontSize * _theme.HeadingBorderPaddingEm),
             Margin = new Thickness(0, isFirstInContainer ? 0 : _theme.HeadingSpacingBefore, 0, _theme.HeadingSpacingAfter),
-            Child = textBlock
+            Child = block
         };
     }
 

From 879cf7f295d51d36dd15c5e67ced8f09648e787b Mon Sep 17 00:00:00 2001
From: Lex Li <support@lextm.com>
Date: Wed, 13 May 2026 19:01:06 -0400
Subject: [PATCH 2/2] Fix heading style

---
 src/WinUI.Markdown/Visitors/NativeMarkdownVisitor.cs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/WinUI.Markdown/Visitors/NativeMarkdownVisitor.cs b/src/WinUI.Markdown/Visitors/NativeMarkdownVisitor.cs
index 6bd07db..0517052 100644
--- a/src/WinUI.Markdown/Visitors/NativeMarkdownVisitor.cs
+++ b/src/WinUI.Markdown/Visitors/NativeMarkdownVisitor.cs
@@ -115,7 +115,12 @@ private FrameworkElement RenderHeading(HeadingBlock heading, bool isFirstInConta
         block.FontWeight = HeadingWeight(sizeIndex);
         block.LineHeight = fontSize * 1.25;
 
-        var paragraph = new Paragraph();
+        var paragraph = new Paragraph
+        {
+            FontSize = fontSize,
+            FontWeight = HeadingWeight(sizeIndex),
+            LineHeight = fontSize * 1.25
+        };
         AppendInlines(paragraph.Inlines, heading.Inline);
         block.Blocks.Add(paragraph);