画像読み込み時のファイルハンドル保持問題を修正

VdLabel/DesktopCatalog.xaml

@@ -25,6 +25,9 @@
     WindowBackdropType="Mica"
     WindowCornerPreference="Default"
     mc:Ignorable="d">
+    <ui:FluentWindow.Resources>
+        <local:FilePathToImageSourceConverter x:Key="filePathToImageConv" />
+    </ui:FluentWindow.Resources>
     <ui:FluentWindow.InputBindings>
         <KeyBinding Key="Esc" Command="ApplicationCommands.Close" />
         <KeyBinding Key="Enter" Command="ApplicationCommands.Close" />
@@ -58,7 +61,7 @@
                             <ui:Image
                                 CornerRadius="8"
                                 Focusable="False"
-                                Source="{Binding ImagePath}" />
+                                Source="{Binding ImagePath, Converter={StaticResource filePathToImageConv}}" />
                             <ItemsControl
                                 Margin="6"
                                 HorizontalAlignment="Left"

VdLabel/MainWindow.xaml

@@ -35,6 +35,7 @@
             <Setter Property="MinWidth" Value="80" />
         </Style>
         <BooleanToVisibilityConverter x:Key="b2vConv" />
+        <local:FilePathToImageSourceConverter x:Key="filePathToImageConv" />
     </ui:FluentWindow.Resources>
     <Grid>
         <DockPanel>
@@ -263,7 +264,7 @@
                                             <Image
                                                 Height="16"
                                                 DockPanel.Dock="Left"
-                                                Source="{Binding ImagePath}" />
+                                                Source="{Binding ImagePath, Converter={StaticResource filePathToImageConv}}" />
                                             <emoji:TextBlock
                                                 Margin="4,0"
                                                 Text="{Binding Title}"
@@ -399,7 +400,7 @@
                                     Grid.ColumnSpan="2"
                                     Height="120"
                                     CornerRadius="4"
-                                    Source="{Binding ImagePath}"
+                                    Source="{Binding ImagePath, Converter={StaticResource filePathToImageConv}}"
                                     Visibility="{Binding IsVisibleImage, Converter={StaticResource b2vConv}}" />
                                 <Label
                                     Grid.Row="8"

VdLabel/OverlayWindow.xaml

@@ -22,6 +22,7 @@
     mc:Ignorable="d">
     <Window.Resources>
         <BooleanToVisibilityConverter x:Key="b2vConv" />
+        <local:FilePathToImageSourceConverter x:Key="filePathToImageConv" />
     </Window.Resources>
     <Grid
         Width="{Binding OverlaySize, Mode=OneWay}"
@@ -73,7 +74,7 @@
                 <Grid>
                     <ui:Image
                         CornerRadius="8"
-                        Source="{Binding ImagePath}"
+                        Source="{Binding ImagePath, Converter={StaticResource filePathToImageConv}}"
                         Visibility="{Binding IsVisibleImage, Converter={StaticResource b2vConv}}" />
                     <ItemsControl
                         Margin="12"

VdLabel/OverlayWindow.xaml.cs

@@ -53,6 +53,42 @@ private void TopMost()
     }
 }
 
+/// <summary>
+/// ファイルパス文字列を ImageSource に変換するコンバーター。
+/// BitmapCacheOption.OnLoad を使用することで、読み込み後にファイルハンドルを解放する。
+/// </summary>
+[ValueConversion(typeof(string), typeof(System.Windows.Media.Imaging.BitmapImage))]
+public sealed class FilePathToImageSourceConverter : IValueConverter
+{
+    public static FilePathToImageSourceConverter Default { get; } = new FilePathToImageSourceConverter();
+
+    public object? Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
+    {
+        if (value is not string path || string.IsNullOrEmpty(path) || !System.IO.File.Exists(path))
+        {
+            return null;
+        }
+
+        try
+        {
+            var bitmap = new System.Windows.Media.Imaging.BitmapImage();
+            bitmap.BeginInit();
+            bitmap.UriSource = new Uri(path, UriKind.Absolute);
+            bitmap.CacheOption = System.Windows.Media.Imaging.BitmapCacheOption.OnLoad;
+            bitmap.EndInit();
+            bitmap.Freeze();
+            return bitmap;
+        }
+        catch
+        {
+            return null;
+        }
+    }
+
+    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
+        => throw new NotSupportedException();
+}
+
 [ValueConversion(typeof(System.Drawing.Color), typeof(SolidColorBrush))]
 public sealed class SystemColorToSolidBrushConverter : IValueConverter
 {