修复原生播放器崩溃的问题

Author: Richasy

src/Desktop/BiliCopilot.UI/Controls/Core/Player/NativePlayer.cs

@@ -31,7 +31,12 @@ protected async override void OnControlLoaded()
     /// <inheritdoc/>
     protected override void OnApplyTemplate()
     {
-        _playerElement = GetTemplateChild("PlayerElement") as MediaPlayerElement;
+        var rootGrid = GetTemplateChild("RootGrid") as Grid;
+        _playerElement = new MediaPlayerElement();
+        _playerElement.HorizontalAlignment = HorizontalAlignment.Stretch;
+        _playerElement.VerticalAlignment = VerticalAlignment.Stretch;
+        _playerElement.AreTransportControlsEnabled = false;
+        rootGrid.Children.Add(_playerElement);
     }
 
     /// <inheritdoc/>

src/Desktop/BiliCopilot.UI/Controls/Core/Player/PlayerResources.xaml

@@ -91,13 +91,7 @@
         <Setter Property="Template">
             <Setter.Value>
                 <ControlTemplate TargetType="local:NativePlayer">
-                    <Grid Background="Black">
-                        <MediaPlayerElement
-                            x:Name="PlayerElement"
-                            HorizontalAlignment="Stretch"
-                            VerticalAlignment="Stretch"
-                            AreTransportControlsEnabled="False" />
-                    </Grid>
+                    <Grid x:Name="RootGrid" Background="Black" />
                 </ControlTemplate>
             </Setter.Value>
         </Setter>

src/Desktop/BiliCopilot.UI/ViewModels/Core/NativePlayerViewModel/NativePlayerViewModel.Overrides.cs

@@ -140,7 +140,7 @@ protected override async Task OnLoadPlayDataAsync()
             await LoadDashVideoSourceAsync();
         }
 
-        _element.SetMediaPlayer(Player);
+        _element?.SetMediaPlayer(Player);
     }
 
     /// <inheritdoc/>