RequestedTheme.Default had no effect. Fixes #101

dotMorten · Apr 13, 2023 · 13085d2 · 13085d2
1 parent 4905982
commit 13085d2
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Showing 2 changed files with 19 additions and 8 deletions.
diff --git a/src/WinUIEx/WinUIEx.csproj b/src/WinUIEx/WinUIEx.csproj
@@ -22,8 +22,9 @@
     <PackageId>WinUIEx</PackageId>
     <Product>WinUI Extensions</Product>
     <PackageReleaseNotes>
-      - Upgrade to Windows App SDK 1.3
-      - Deprecated Backdrop APIs in favor of Microsoft's new Backdrop APIs
+      - Upgrade to Windows App SDK 1.3.
+      - Deprecated Backdrop APIs in favor of Microsoft's new Backdrop APIs.
+      - Setting Default RequestedTheme has no effect (Issue #101)
     </PackageReleaseNotes>
   </PropertyGroup>
 

diff --git a/src/WinUIEx/WindowEx.cs b/src/WinUIEx/WindowEx.cs
@@ -177,18 +177,28 @@ public object? WindowContent
         {
             get => windowArea.Content;
             set 
-            { 
-                if(windowArea.Content is FrameworkElement oldelm)
-                    oldelm.ActualThemeChanged -= WindowContent_ActualThemeChanged;
+            {
+                if (windowArea.Content is FrameworkElement oldelm)
+                {
+                    if (_propChangedCallbackId != 0)
+                    {
+                        oldelm.UnregisterPropertyChangedCallback(FrameworkElement.RequestedThemeProperty, _propChangedCallbackId);
+                        _propChangedCallbackId = 0;
+                    }
+                }
                 windowArea.Content = value;
                 if (windowArea.Content is FrameworkElement newelm)
-                    newelm.ActualThemeChanged += WindowContent_ActualThemeChanged;
+                {
+                    _propChangedCallbackId = newelm.RegisterPropertyChangedCallback(FrameworkElement.RequestedThemeProperty, RequestedThemePropertyChanged);
+                }
             }
         }
 
-        private void WindowContent_ActualThemeChanged(FrameworkElement sender, object args)
+        private long _propChangedCallbackId;
+
+        private void RequestedThemePropertyChanged(DependencyObject sender, DependencyProperty dp)
         {
-            if(this.Content is FrameworkElement elm && windowArea.Content is FrameworkElement childelm)
+            if (this.Content is FrameworkElement elm && windowArea.Content is FrameworkElement childelm)
             {
                 elm.RequestedTheme = childelm.RequestedTheme;
             }