Fix Preview CornerRadius (Get BasedOn Style)

Author: onesounds

Flow.Launcher.Core/Resource/Theme.cs

@@ -771,22 +771,18 @@ private void ApplyPreviewBackground(Color? bgColor = null)
         {
             if (bgColor == null) return;
 
-            // Copy the existing WindowBorderStyle
+            // Create a new Style for the preview
             var previewStyle = new Style(typeof(Border));
-            if (Application.Current.Resources.Contains("WindowBorderStyle"))
+
+            // Get the original WindowBorderStyle
+            if (Application.Current.Resources.Contains("WindowBorderStyle") &&
+                Application.Current.Resources["WindowBorderStyle"] is Style originalStyle)
             {
-                if (Application.Current.Resources["WindowBorderStyle"] is Style originalStyle)
-                {
-                    foreach (var setter in originalStyle.Setters.OfType<Setter>())
-                    {
-                        previewStyle.Setters.Add(new Setter(setter.Property, setter.Value));
-                    }
-                }
+                // Copy the original style, including the base style if it exists
+                CopyStyle(originalStyle, previewStyle);
             }
 
             // Apply background color (remove transparency in color)
-            // WPF does not allow the use of an acrylic brush within the window's internal area,
-            // so transparency effects are not applied to the preview.
             Color backgroundColor = Color.FromRgb(bgColor.Value.R, bgColor.Value.G, bgColor.Value.B);
             previewStyle.Setters.Add(new Setter(Border.BackgroundProperty, new SolidColorBrush(backgroundColor)));
 
@@ -797,9 +793,26 @@ private void ApplyPreviewBackground(Color? bgColor = null)
                 previewStyle.Setters.Add(new Setter(Border.CornerRadiusProperty, new CornerRadius(5)));
                 previewStyle.Setters.Add(new Setter(Border.BorderThicknessProperty, new Thickness(1)));
             }
+
+            // Set the new style to the resource
             Application.Current.Resources["PreviewWindowBorderStyle"] = previewStyle;
         }
 
+        private void CopyStyle(Style originalStyle, Style targetStyle)
+        {
+            // If the style is based on another style, copy the base style first
+            if (originalStyle.BasedOn != null)
+            {
+                CopyStyle(originalStyle.BasedOn, targetStyle);
+            }
+
+            // Copy the setters from the original style
+            foreach (var setter in originalStyle.Setters.OfType<Setter>())
+            {
+                targetStyle.Setters.Add(new Setter(setter.Property, setter.Value));
+            }
+        }
+
         private void ColorizeWindow(string theme, BackdropTypes backdropType)
         {
             var dict = GetThemeResourceDictionary(theme);

Flow.Launcher/SettingWindow.xaml

@@ -19,9 +19,9 @@
     MouseDown="window_MouseDown"
     ResizeMode="CanResize"
     SnapsToDevicePixels="True"
-    UseLayoutRounding="True"
     StateChanged="Window_StateChanged"
     Top="{Binding SettingWindowTop, Mode=TwoWay}"
+    UseLayoutRounding="True"
     WindowStartupLocation="Manual"
     mc:Ignorable="d">
     <WindowChrome.WindowChrome>