聊天框超过大小时自动滚动到最底层

VPet-Simulator.Core/Display/MessageBar.xaml

@@ -21,10 +21,10 @@
             <Label x:Name="LName" Content="虚拟桌宠名字:" Foreground="{DynamicResource PrimaryText}"
                     HorizontalAlignment="Left" Padding="0" FontWeight="Bold" Margin="0,0,0,6" FontSize="32"
                     Background="{x:Null}" />
-            <ScrollViewer MaxHeight="400">
+            <ScrollViewer x:Name="sv" MaxHeight="400">
                 <TextBox x:Name="TText" Text="我说话长这样,这是我说的话巴拉巴拉巴拉巴拉巴拉巴拉巴拉巴拉巴拉巴拉巴拉巴拉巴拉巴拉" IsReadOnly="True"
                         TextWrapping="WrapWithOverflow" FontSize="24" x:FieldModifier="public" Background="{x:Null}"
-                        BorderBrush="{x:Null}" BorderThickness="0" />
+                        BorderBrush="{x:Null}" BorderThickness="0" SizeChanged="TText_SizeChanged" />
             </ScrollViewer>
             <Grid x:Name="MessageBoxContent" x:FieldModifier="public">
 

VPet-Simulator.Core/Display/MessageBar.xaml.cs

@@ -221,5 +221,10 @@ namespace VPet_Simulator.Core
         private void ContextMenu_Opened(object sender, RoutedEventArgs e) => Border_MouseEnter(null, null);
 
         private void ContextMenu_Closed(object sender, RoutedEventArgs e) => Border_MouseLeave(null, null);
+
+        private void TText_SizeChanged(object sender, SizeChangedEventArgs e)
+        {
+            sv.ScrollToEnd();
+        }
     }
 }

VPet-Simulator.Core/Display/ToolBar.xaml.cs

@@ -249,12 +249,12 @@ namespace VPet_Simulator.Core
         public event Action EventShow;
         public void Show()
         {
+            EventShow?.Invoke();
             if (m.UIGrid.Children.IndexOf(this) != m.UIGrid.Children.Count - 1)
             {
                 Panel.SetZIndex(this, m.UIGrid.Children.Count);
             }
             Visibility = Visibility.Visible;
-            EventShow?.Invoke();
             if (CloseTimer.Enabled)
                 onFocus = true;
             else