little optimized

Pixiview/Illust/IllustCollectionPage.cs

@@ -94,6 +94,7 @@ namespace Pixiview.Illust
 
         public override void OnUnload()
         {
+            InvalidateCollection();
             Illusts = null;
             lastUpdated = default;
         }
@@ -298,7 +299,11 @@ namespace Pixiview.Illust
         {
             if (scrollView.ScrollY > -topOffset)
             {
+#if __IOS__
                 await scrollView.ScrollToAsync(0, -topOffset, true);
+#else
+                await scrollView.ScrollToAsync(0, -topOffset, false);
+#endif
             }
         }
 

Pixiview/Illust/ViewIllustPage.xaml

@@ -31,7 +31,11 @@
 
         <ProgressBar x:Name="progress" IsVisible="{Binding ProgressVisible}"
                      Progress="0.05"
-                     VerticalOptions="Start"/>
+                     VerticalOptions="Start">
+            <ProgressBar.Margin>
+                <OnPlatform x:TypeArguments="Thickness" Android="0, -6, 0, 0"/>
+            </ProgressBar.Margin>
+        </ProgressBar>
 
         <u:RoundLabel Text="{Binding PagePositionText}"
                       BackgroundColor="{DynamicResource MaskColor}" Margin="0, 6, 6, 0"