fixed a bug of tabcontrol

src/Shared/HandyControl_Shared/Controls/TabControl/TabControl.cs

@@ -15,6 +15,7 @@ namespace HandyControl.Controls
     [TemplatePart(Name = OverflowScrollviewer, Type = typeof(ScrollViewer))]
     [TemplatePart(Name = ScrollButtonLeft, Type = typeof(Button))]
     [TemplatePart(Name = ScrollButtonRight, Type = typeof(Button))]
+    [TemplatePart(Name = HeaderBorder, Type = typeof(Border))]
     public class TabControl : System.Windows.Controls.TabControl
     {
         private const string OverflowButtonKey = "PART_OverflowButton";
@@ -27,6 +28,8 @@ namespace HandyControl.Controls
 
         private const string ScrollButtonRight = "PART_ScrollButtonRight";
 
+        private const string HeaderBorder = "PART_HeaderBorder";
+
         private ContextMenuToggleButton _buttonOverflow;
 
         private TabPanel _headerPanel;
@@ -37,6 +40,8 @@ namespace HandyControl.Controls
 
         private Button _buttonScrollRight;
 
+        private Border _headerBorder;
+
         /// <summary>
         ///     是否为内部操作
         /// </summary>
@@ -220,6 +225,9 @@ namespace HandyControl.Controls
                     item.TabPanel = _headerPanel;
                 }
             }
+
+            _headerBorder?.InvalidateMeasure();
+
             IsInternalAction = false;
         }
 
@@ -248,6 +256,7 @@ namespace HandyControl.Controls
             _scrollViewerOverflow = GetTemplateChild(OverflowScrollviewer) as ScrollViewer;
             _buttonScrollLeft = GetTemplateChild(ScrollButtonLeft) as Button;
             _buttonScrollRight = GetTemplateChild(ScrollButtonRight) as Button;
+            _headerBorder = GetTemplateChild(HeaderBorder) as Border;
 
             if (_buttonScrollLeft != null) _buttonScrollLeft.Click += ButtonScrollLeft_Click;
             if (_buttonScrollRight != null) _buttonScrollRight.Click += ButtonScrollRight_Click;

src/Shared/HandyControl_Shared/Themes/Styles/TabControl.xaml

@@ -122,7 +122,7 @@
                     <Button Focusable="False" Style="{StaticResource ButtonIcon}" Padding="8" controls:IconElement.Geometry="{StaticResource LeftGeometry}" Foreground="{DynamicResource PrimaryTextBrush}" Background="{DynamicResource SecondaryRegionBrush}" x:Name="PART_ScrollButtonLeft"/>
                 </Border>
                 <controls:ScrollViewer HorizontalScrollBarVisibility="Hidden" CanMouseWheel="True" Orientation="Horizontal" IsEnableInertia="True" Grid.Row="0" Grid.Column="1" IsDeferredScrollingEnabled="True" x:Name="PART_OverflowScrollviewer">
-                    <Border Background="{TemplateBinding Background}" BorderThickness="0,0,0,1" BorderBrush="{DynamicResource BorderBrush}" >
+                    <Border Background="{TemplateBinding Background}" BorderThickness="0,0,0,1" BorderBrush="{DynamicResource BorderBrush}" Name="PART_HeaderBorder">
                         <controls:TabPanel MinHeight="{TemplateBinding TabItemHeight}" TabItemHeight="{TemplateBinding TabItemHeight}" TabItemWidth="{TemplateBinding TabItemWidth}" IsEnableTabFill="{TemplateBinding IsEnableTabFill}" Margin="0,0,-1,-1" x:Name="PART_HeaderPanel" HorizontalAlignment="Left" Background="{DynamicResource SecondaryTextBrush}" IsItemsHost="true" KeyboardNavigation.TabIndex="1" Panel.ZIndex="1">
                             <interactivity:Interaction.Behaviors>
                                 <interactivity:FluidMoveBehavior AppliesTo="Children" Duration="{Binding FluidMoveDuration,ElementName=PART_HeaderPanel}">