From 9e33282d0794c284aeb5eb2ce0f985fad4efcb4e Mon Sep 17 00:00:00 2001
From: ClemensFischer <fischer.clemens@gmail.com>
Date: Thu, 4 Sep 2025 08:11:15 +0200
Subject: [PATCH] GroundOverlay performance

---
 MapControl/Avalonia/ImageLoader.Avalonia.cs |  2 +-
 MapControl/Shared/GroundOverlay.cs          | 35 ++++++++++++---------
 MapControl/WPF/ImageLoader.WPF.cs           |  2 +-
 3 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/MapControl/Avalonia/ImageLoader.Avalonia.cs b/MapControl/Avalonia/ImageLoader.Avalonia.cs
index d50dca81..9986fc1b 100644
--- a/MapControl/Avalonia/ImageLoader.Avalonia.cs
+++ b/MapControl/Avalonia/ImageLoader.Avalonia.cs
@@ -22,7 +22,7 @@ namespace MapControl
 
         public static Task<IImage> LoadImageAsync(Stream stream)
         {
-            return Task.FromResult(LoadImage(stream));
+            return Task.Run(() => LoadImage(stream));
         }
 
         public static async Task<IImage> LoadImageAsync(string path)
diff --git a/MapControl/Shared/GroundOverlay.cs b/MapControl/Shared/GroundOverlay.cs
index fe70e681..8ed1b4f5 100644
--- a/MapControl/Shared/GroundOverlay.cs
+++ b/MapControl/Shared/GroundOverlay.cs
@@ -37,7 +37,21 @@ namespace MapControl
                 ZIndex = zIndex;
             }
 
-            public async Task Load()
+            public async Task LoadStream(ZipArchive archive)
+            {
+                var entry = archive.GetEntry(ImagePath);
+
+                if (entry != null)
+                {
+                    using (var zipStream = entry.Open())
+                    {
+                        Stream = new MemoryStream((int)zipStream.Length);
+                        await zipStream.CopyToAsync(Stream);
+                    }
+                }
+            }
+
+            public async Task LoadImage()
             {
                 if (Stream != null)
                 {
@@ -46,7 +60,7 @@ namespace MapControl
                 }
             }
 
-            public async Task Load(Uri docUri)
+            public async Task LoadImage(Uri docUri)
             {
                 ImageSource = await ImageLoader.LoadImageAsync(new Uri(docUri, ImagePath));
             }
@@ -141,19 +155,10 @@ namespace MapControl
 
                 foreach (var imageOverlay in imageOverlays)
                 {
-                    var imageEntry = archive.GetEntry(imageOverlay.ImagePath);
-
-                    if (imageEntry != null)
-                    {
-                        using (var zipStream = imageEntry.Open())
-                        {
-                            imageOverlay.Stream = new MemoryStream((int)zipStream.Length);
-                            await zipStream.CopyToAsync(imageOverlay.Stream);
-                        }
-                    }
+                    await imageOverlay.LoadStream(archive);
                 }
 
-                Parallel.ForEach(imageOverlays, async imageOverlay => await imageOverlay.Load());
+                await Task.WhenAll(imageOverlays.Select(imageOverlay => imageOverlay.LoadImage()));
 
                 return imageOverlays;
             }
@@ -172,7 +177,7 @@ namespace MapControl
 
             var docUri = new Uri(docFilePath);
 
-            Parallel.ForEach(imageOverlays, async imageOverlay => await imageOverlay.Load(docUri));
+            await Task.WhenAll(imageOverlays.Select(imageOverlay => imageOverlay.LoadImage(docUri)));
 
             return imageOverlays;
         }
@@ -180,7 +185,7 @@ namespace MapControl
         private static async Task<List<ImageOverlay>> ReadGroundOverlays(Stream docStream)
         {
 #if NETFRAMEWORK
-            var document = await Task.FromResult(XDocument.Load(docStream, LoadOptions.None));
+            var document = await Task.Run(() => XDocument.Load(docStream, LoadOptions.None));
 #else
             var document = await XDocument.LoadAsync(docStream, LoadOptions.None, System.Threading.CancellationToken.None);
 #endif
diff --git a/MapControl/WPF/ImageLoader.WPF.cs b/MapControl/WPF/ImageLoader.WPF.cs
index e2224502..236ed9dd 100644
--- a/MapControl/WPF/ImageLoader.WPF.cs
+++ b/MapControl/WPF/ImageLoader.WPF.cs
@@ -29,7 +29,7 @@ namespace MapControl
 
         public static Task<ImageSource> LoadImageAsync(Stream stream)
         {
-            return Task.FromResult(LoadImage(stream));
+            return Task.Run(() => LoadImage(stream));
         }
 
         public static async Task<ImageSource> LoadImageAsync(string path)