fixed a bug

src/Shared/HandyControlDemo_Shared/UserControl/Controls/TabControlDemoCtl.xaml

@@ -36,7 +36,7 @@
                     <Label Style="{StaticResource LabelPrimary}" Margin="16,0,0,0" Content="IsDraggable = True"/>
                     <Label Style="{StaticResource LabelPrimary}" Margin="16,0,0,0" Content="IsEnableAnimation = True"/>
                 </StackPanel>
-                <controls:TabControl IsScrollable="True" IsEnableAnimation="True" ShowCloseButton="True" IsDraggable="True" Margin="32,0,32,32" Width="800" Height="300">
+                <controls:TabControl IsEnableAnimation="True" ShowCloseButton="True" IsDraggable="True" IsEnableTabFill="True" Margin="32,0,32,32" Width="800" Height="300">
                     <controls:TabItem Header="TabItem1">
                         <controls:SimplePanel Background="White"/>
                     </controls:TabItem>

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

@@ -3,6 +3,7 @@ using System.Collections.Specialized;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Controls.Primitives;
+using System.Windows.Input;
 using HandyControl.Data;
 using HandyControl.Tools.Extension;
 
@@ -236,33 +237,15 @@ namespace HandyControl.Controls
             }
         }
 
-        private void Menu_Closed(object sender, RoutedEventArgs e)
+        private void Menu_Closed(object sender, RoutedEventArgs e) => _buttonOverflow.IsChecked = false;
-        {
-            _buttonOverflow.IsChecked = false;
-        }
 
-        private void ButtonScrollRight_Click(object sender, RoutedEventArgs e)
+        private void ButtonScrollRight_Click(object sender, RoutedEventArgs e) =>
-        {
+            _scrollviewerOverflow.ScrollToHorizontalOffsetInternal(Math.Min(
-            var currentOffset = _scrollviewerOverflow.CurrentHorizontalOffset;
+                _scrollviewerOverflow.CurrentHorizontalOffset + TabItemWidth, _scrollviewerOverflow.ScrollableWidth));
-            var offset = currentOffset + (TabItemWidth - currentOffset % TabItemWidth);
 
-            if (offset <= _scrollviewerOverflow.ScrollableWidth)
+        private void ButtonScrollLeft_Click(object sender, RoutedEventArgs e) =>
-            {
+            _scrollviewerOverflow.ScrollToHorizontalOffsetInternal(Math.Max(
-                _scrollviewerOverflow.ScrollToHorizontalOffsetInternal(offset);
+                _scrollviewerOverflow.CurrentHorizontalOffset - TabItemWidth, 0));
-            }
-        }
-
-        private void ButtonScrollLeft_Click(object sender, RoutedEventArgs e)
-        {
-            var currentOffset = _scrollviewerOverflow.CurrentHorizontalOffset;
-            var modulo = currentOffset % TabItemWidth;
-            var offset = currentOffset - (modulo < 1e-6 ? TabItemWidth : modulo);
-
-            if (offset >= 0)
-            {
-                _scrollviewerOverflow.ScrollToHorizontalOffsetInternal(offset);
-            }
-        }
 
         private void ButtonOverflow_Click(object sender, RoutedEventArgs e)
         {
@@ -304,5 +287,12 @@ namespace HandyControl.Controls
                 }
             }
         }
+
+        internal double GetHorizontalOffset() => _scrollviewerOverflow?.CurrentHorizontalOffset ?? 0;
+
+        internal void UpdateScroll() => _scrollviewerOverflow?.RaiseEvent(new MouseWheelEventArgs(Mouse.PrimaryDevice, Environment.TickCount, 0)
+        {
+            RoutedEvent = MouseWheelEvent
+        });
     }
 }

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

@@ -87,6 +87,11 @@ namespace HandyControl.Controls
         /// </summary>
         private int _currentIndex;
 
+        /// <summary>
+        ///     标签容器横向滚动距离
+        /// </summary>
+        private double _scrollHorizontalOffset;
+
         /// <summary>
         ///     标签容器
         /// </summary>
@@ -178,17 +183,21 @@ namespace HandyControl.Controls
             base.OnMouseLeftButtonDown(e);
             if (TabControlParent.IsDraggable && !ItemIsDragging && !_isDragging)
             {
+                TabControlParent.UpdateScroll();
                 TabPanel.FluidMoveDuration = new Duration(TimeSpan.FromSeconds(0));
                 _mouseDownOffsetX = RenderTransform.Value.OffsetX;
-                var mx = TranslatePoint(new Point(), TabControlParent).X;
+                _scrollHorizontalOffset = TabControlParent.GetHorizontalOffset();
+                var mx = TranslatePoint(new Point(), TabControlParent).X + _scrollHorizontalOffset;
                 _mouseDownIndex = CalLocationIndex(mx);
-                _maxMoveLeft = -_mouseDownIndex * ItemWidth;
+                var subIndex = _mouseDownIndex - CalLocationIndex(_scrollHorizontalOffset);
+                _maxMoveLeft = -subIndex * ItemWidth;
                 _maxMoveRight = TabControlParent.ActualWidth - ActualWidth + _maxMoveLeft;
 
                 _isDragging = true;
                 ItemIsDragging = true;
                 _isWaiting = true;
                 _dragPoint = e.GetPosition(TabControlParent);
+                _dragPoint = new Point(_dragPoint.X + +_scrollHorizontalOffset, _dragPoint.Y);
                 _mouseDownPoint = _dragPoint;
                 CaptureMouse();
             }
@@ -199,9 +208,10 @@ namespace HandyControl.Controls
             base.OnMouseMove(e);
             if (ItemIsDragging && _isDragging)
             {
-                var subX = TranslatePoint(new Point(), TabControlParent).X;
+                var subX = TranslatePoint(new Point(), TabControlParent).X + _scrollHorizontalOffset;
                 CurrentIndex = CalLocationIndex(subX);
                 var p = e.GetPosition(TabControlParent);
+                p = new Point(p.X + _scrollHorizontalOffset, p.Y);
                 var subLeft = p.X - _dragPoint.X;
                 var totalLeft = p.X - _mouseDownPoint.X;
 
@@ -229,7 +239,7 @@ namespace HandyControl.Controls
             ReleaseMouseCapture();
             if (_isDragged)
             {
-                var subX = TranslatePoint(new Point(), TabControlParent).X;
+                var subX = TranslatePoint(new Point(), TabControlParent).X + _scrollHorizontalOffset;
                 var index = CalLocationIndex(subX);
                 var left = index * ItemWidth;
                 var offsetX = RenderTransform.Value.OffsetX;
@@ -273,7 +283,7 @@ namespace HandyControl.Controls
             animation.Completed += (s1, e1) => AnimationCompleted();
             var f = new TranslateTransform(offsetX, 0);
             RenderTransform = f;
-            f.BeginAnimation(TranslateTransform.XProperty, animation);
+            f.BeginAnimation(TranslateTransform.XProperty, animation, HandoffBehavior.Compose);
         }
 
         /// <summary>

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

@@ -79,8 +79,8 @@
                     <ColumnDefinition x:Name="ColumnDefinition1" Width="0"/>
                 </Grid.ColumnDefinitions>
                 <Grid.RowDefinitions>
-                    <RowDefinition x:Name="RowDefinition0" Height="Auto"/>
+                    <RowDefinition Height="Auto"/>
-                    <RowDefinition x:Name="RowDefinition1" Height="*"/>
+                    <RowDefinition Height="*"/>
                 </Grid.RowDefinitions>
                 <Border Background="{TemplateBinding Background}" BorderThickness="0,0,0,1" BorderBrush="{DynamicResource BorderBrush}">
                     <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">
@@ -107,39 +107,34 @@
         <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}">
             <Grid x:Name="templateRoot" ClipToBounds="true" SnapsToDevicePixels="true" KeyboardNavigation.TabNavigation="Local">
                 <Grid.ColumnDefinitions>
-                    <ColumnDefinition x:Name="ColumnDefinition0"/>
+                    <ColumnDefinition Width="Auto"/>
-                    <ColumnDefinition x:Name="ColumnDefinition1" Width="0"/>
+                    <ColumnDefinition/>
+                    <ColumnDefinition Width="Auto"/>
                 </Grid.ColumnDefinitions>
                 <Grid.RowDefinitions>
-                    <RowDefinition x:Name="RowDefinition0" Height="Auto"/>
+                    <RowDefinition Height="Auto"/>
-                    <RowDefinition x:Name="RowDefinition1" Height="*"/>
+                    <RowDefinition Height="*"/>
                 </Grid.RowDefinitions>
-                <Grid>
+                <Border Visibility="{Binding Visibility,ElementName=PART_OverflowButton}" Margin="0,-1,0,0" Grid.Row="0" Grid.Column="0" BorderThickness="0,0,1,1" BorderBrush="{DynamicResource BorderBrush}" Background="{DynamicResource RegionBrush}" HorizontalAlignment="Left" Panel.ZIndex="2">
-                    <Grid.ColumnDefinitions>
+                    <Border.CacheMode>
-                        <ColumnDefinition Width="Auto"/>
+                        <BitmapCache SnapsToDevicePixels="True"/>
-                        <ColumnDefinition Width="*"/>
+                    </Border.CacheMode>
-                    </Grid.ColumnDefinitions>
+                    <Button Style="{StaticResource ButtonIcon}" Padding="8" controls:IconElement.Geometry="{StaticResource LeftGeometry}" Foreground="{DynamicResource PrimaryTextBrush}" Background="{DynamicResource SecondaryRegionBrush}" x:Name="PART_ScrollButtonLeft"/>
-                    <Border Visibility="{Binding Visibility,ElementName=PART_OverflowButton}" Margin="0,-1,0,0" Grid.Row="0" Grid.Column="0" BorderThickness="0,0,1,1" BorderBrush="{DynamicResource BorderBrush}" Background="{DynamicResource RegionBrush}" HorizontalAlignment="Left" Panel.ZIndex="2">
+                </Border>
-                        <Border.CacheMode>
+                <controls:ScrollViewer HorizontalScrollBarVisibility="Hidden" CanMouseWheel="True" Orientation="Horizontal" IsEnableInertia="True" Grid.Row="0" Grid.Column="1" IsDeferredScrollingEnabled="True" x:Name="PART_OverflowScrollviewer">
-                            <BitmapCache SnapsToDevicePixels="True"/>
+                    <Border Background="{TemplateBinding Background}" BorderThickness="0,0,0,1" BorderBrush="{DynamicResource BorderBrush}" >
-                        </Border.CacheMode>
+                        <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">
-                        <Button Style="{StaticResource ButtonIcon}" Padding="8" controls:IconElement.Geometry="{StaticResource LeftGeometry}" Foreground="{DynamicResource PrimaryTextBrush}" Background="{DynamicResource SecondaryRegionBrush}" x:Name="PART_ScrollButtonLeft"/>
+                            <interactivity:Interaction.Behaviors>
+                                <interactivity:FluidMoveBehavior AppliesTo="Children" Duration="{Binding FluidMoveDuration,ElementName=PART_HeaderPanel}">
+                                    <interactivity:FluidMoveBehavior.EaseX>
+                                        <CubicEase EasingMode="EaseOut"/>
+                                    </interactivity:FluidMoveBehavior.EaseX>
+                                </interactivity:FluidMoveBehavior>
+                            </interactivity:Interaction.Behaviors>
+                        </controls:TabPanel>
                     </Border>
-                    <controls:ScrollViewer HorizontalScrollBarVisibility="Hidden" CanMouseWheel="True" Orientation="Horizontal" IsEnableInertia="True" Grid.Column="1" IsDeferredScrollingEnabled="True" x:Name="PART_OverflowScrollviewer">
+                </controls:ScrollViewer>
-                        <Border Background="{TemplateBinding Background}" BorderThickness="0,0,0,1" BorderBrush="{DynamicResource BorderBrush}" >
+                <Border Visibility="{Binding Visibility,ElementName=PART_OverflowButton}" Margin="0,-1,0,0" Grid.Row="0" Grid.Column="2" BorderThickness="1,0,0,1" BorderBrush="{DynamicResource BorderBrush}" Background="{DynamicResource RegionBrush}" HorizontalAlignment="Right">
-                            <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}">
-                                        <interactivity:FluidMoveBehavior.EaseX>
-                                            <CubicEase EasingMode="EaseOut"/>
-                                        </interactivity:FluidMoveBehavior.EaseX>
-                                    </interactivity:FluidMoveBehavior>
-                                </interactivity:Interaction.Behaviors>
-                            </controls:TabPanel>
-                        </Border>
-                    </controls:ScrollViewer>
-                </Grid>
-                <Border Visibility="{Binding Visibility,ElementName=PART_OverflowButton}" Margin="0,-1,0,0" Grid.Row="0" Grid.Column="0" BorderThickness="1,0,0,1" BorderBrush="{DynamicResource BorderBrush}" Background="{DynamicResource RegionBrush}" HorizontalAlignment="Right">
                     <Border.CacheMode>
                         <BitmapCache SnapsToDevicePixels="True"/>
                     </Border.CacheMode>
@@ -148,7 +143,7 @@
                         <controls:ContextMenuToggleButton x:Name="PART_OverflowButton" Visibility="Collapsed" Style="{StaticResource ToggleButtonIconTransparent}" controls:IconSwitchElement.Geometry="{StaticResource DownGeometry}" controls:IconSwitchElement.GeometrySelected="{StaticResource UpGeometry}"/>
                     </StackPanel>
                 </Border>
-                <Border x:Name="contentPanel" Background="{DynamicResource SecondaryRegionBrush}" Grid.Column="0" KeyboardNavigation.DirectionalNavigation="Contained" Grid.Row="1" KeyboardNavigation.TabIndex="2" KeyboardNavigation.TabNavigation="Local">
+                <Border x:Name="contentPanel" Background="{DynamicResource SecondaryRegionBrush}" KeyboardNavigation.DirectionalNavigation="Contained" Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="3" KeyboardNavigation.TabIndex="2" KeyboardNavigation.TabNavigation="Local">
                     <ContentPresenter x:Name="PART_SelectedContentHost" ContentSource="SelectedContent" Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                 </Border>
             </Grid>
@@ -164,9 +159,13 @@
         <Setter Property="BorderThickness" Value="1"/>
         <Setter Property="Template" Value="{StaticResource TabControlPlusTemplate}"/>
         <Style.Triggers>
-            <Trigger Property="IsScrollable" Value="True">
+            <MultiTrigger>
+                <MultiTrigger.Conditions>
+                    <Condition Property="IsScrollable" Value="True"/>
+                    <Condition Property="IsEnableTabFill" Value="False"/>
+                </MultiTrigger.Conditions>
                 <Setter Property="Template" Value="{StaticResource TabControlPlusScrollableTemplate}"/>
-            </Trigger>
+            </MultiTrigger>
         </Style.Triggers>
     </Style>