From bd96a9709fa529469e6aba67be201a8e28ca9450 Mon Sep 17 00:00:00 2001
From: leo <longshuang@msn.cn>
Date: Sun, 12 Jul 2020 22:24:59 +0800
Subject: [PATCH] Auto scroll when text changed or selection changed in a
 TextBox

---
 SourceGit/Helpers/TextBoxHelper.cs      | 368 +++++++++++++++---------
 SourceGit/Resources/Styles/TextBox.xaml | 230 +++++++--------
 SourceGit/SourceGit.csproj              |  34 +--
 SourceGit/UI/WorkingCopy.xaml           |   3 +-
 SourceGit/UI/WorkingCopy.xaml.cs        |   4 -
 5 files changed, 360 insertions(+), 279 deletions(-)

diff --git a/SourceGit/Helpers/TextBoxHelper.cs b/SourceGit/Helpers/TextBoxHelper.cs
index 3f34aed8..df6d901d 100644
--- a/SourceGit/Helpers/TextBoxHelper.cs
+++ b/SourceGit/Helpers/TextBoxHelper.cs
@@ -1,143 +1,225 @@
-using System.Windows;
-using System.Windows.Controls;
-using System.Windows.Media;
-
-namespace SourceGit.Helpers {
-
-    /// <summary>
-    ///     Attached properties to TextBox.
-    /// </summary>
-    public static class TextBoxHelper {
-
-        /// <summary>
-        ///     Placeholder property  
-        /// </summary>
-        public static readonly DependencyProperty PlaceholderProperty = DependencyProperty.RegisterAttached(
-            "Placeholder",
-            typeof(string),
-            typeof(TextBoxHelper),
-            new PropertyMetadata(string.Empty, OnPlaceholderChanged));
-
-        /// <summary>
-        ///     Vertical alignment for placeholder.
-        /// </summary>
-        public static readonly DependencyProperty PlaceholderBaselineProperty = DependencyProperty.RegisterAttached(
-            "PlaceholderBaseline",
-            typeof(AlignmentY),
-            typeof(TextBoxHelper),
-            new PropertyMetadata(AlignmentY.Center));
-
-        /// <summary>
-        ///     Property to store generated placeholder brush.
-        /// </summary>
-        public static readonly DependencyProperty PlaceholderBrushProperty = DependencyProperty.RegisterAttached(
-            "PlaceholderBrush",
-            typeof(Brush),
-            typeof(TextBoxHelper),
-            new PropertyMetadata(Brushes.Transparent));
-
-        /// <summary>
-        ///     Triggered when placeholder changed.
-        /// </summary>
-        /// <param name="d"></param>
-        /// <param name="e"></param>
-        private static void OnPlaceholderChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
-            var textBox = d as TextBox;
-            if (textBox != null) textBox.Loaded += OnTextLoaded;
-        }
-
-        /// <summary>
-        ///     Setter for Placeholder property
-        /// </summary>
-        /// <param name="element"></param>
-        /// <param name="value"></param>
-        public static void SetPlaceholder(UIElement element, string value) {
-            element.SetValue(PlaceholderProperty, value);
-        }
-
-        /// <summary>
-        ///     Getter for Placeholder property
-        /// </summary>
-        /// <param name="element"></param>
-        /// <returns></returns>
-        public static string GetPlaceholder(UIElement element) {
-            return (string)element.GetValue(PlaceholderProperty);
-        }
-
-        /// <summary>
-        ///     Setter for PlaceholderBaseline property
-        /// </summary>
-        /// <param name="element"></param>
-        /// <param name="align"></param>
-        public static void SetPlaceholderBaseline(UIElement element, AlignmentY align) {
-            element.SetValue(PlaceholderBaselineProperty, align);
-        }
-
-        /// <summary>
-        ///     Setter for PlaceholderBaseline property.
-        /// </summary>
-        /// <param name="element"></param>
-        /// <returns></returns>
-        public static AlignmentY GetPlaceholderBaseline(UIElement element) {
-            return (AlignmentY)element.GetValue(PlaceholderBaselineProperty);
-        }
-
-        /// <summary>
-        ///     Setter for PlaceholderBrush property.
-        /// </summary>
-        /// <param name="element"></param>
-        /// <param name="value"></param>
-        public static void SetPlaceholderBrush(UIElement element, Brush value) {
-            element.SetValue(PlaceholderBrushProperty, value);
-        }
-
-        /// <summary>
-        ///     Getter for PlaceholderBrush property.
-        /// </summary>
-        /// <param name="element"></param>
-        /// <returns></returns>
-        public static Brush GetPlaceholderBrush(UIElement element) {
-            return (Brush)element.GetValue(PlaceholderBrushProperty);
-        }
-
-        /// <summary>
-        ///     Set placeholder as background when TextBox was loaded.
-        /// </summary>
-        /// <param name="sender"></param>
-        /// <param name="e"></param>
-        private static void OnTextLoaded(object sender, RoutedEventArgs e) {
-            var textBox = sender as TextBox;
-            if (textBox == null) return;
-
-            Label placeholder = new Label();
-            placeholder.Content = textBox.GetValue(PlaceholderProperty);
-
-            VisualBrush brush = new VisualBrush();
-            brush.AlignmentX = AlignmentX.Left;
-            brush.AlignmentY = GetPlaceholderBaseline(textBox);
-            brush.TileMode = TileMode.None;
-            brush.Stretch = Stretch.None;
-            brush.Opacity = 0.3;
-            brush.Visual = placeholder;
-
-            textBox.SetValue(PlaceholderBrushProperty, brush);
-            textBox.Background = brush;
-            textBox.TextChanged += OnTextChanged;
-            OnTextChanged(textBox, null);
-        }
-
-        /// <summary>
-        ///     Dynamically hide/show placeholder.
-        /// </summary>
-        /// <param name="sender"></param>
-        /// <param name="e"></param>
-        private static void OnTextChanged(object sender, RoutedEventArgs e) {
-            var textBox = sender as TextBox;
-            if (string.IsNullOrEmpty(textBox.Text)) {
-                textBox.Background = textBox.GetValue(PlaceholderBrushProperty) as Brush;
-            } else {
-                textBox.Background = Brushes.Transparent;
-            }
-        }
-    }
-}
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Input;
+using System.Windows.Media;
+
+namespace SourceGit.Helpers {
+
+    /// <summary>
+    ///     Attached properties to TextBox.
+    /// </summary>
+    public static class TextBoxHelper {
+
+        /// <summary>
+        ///     Auto scroll on text changed.
+        /// </summary>
+        public static readonly DependencyProperty AutoScrollProperty = DependencyProperty.RegisterAttached(
+            "AutoScroll",
+            typeof(bool),
+            typeof(TextBoxHelper),
+            new PropertyMetadata(false, OnAutoScrollChanged));
+
+        /// <summary>
+        ///     Placeholder property  
+        /// </summary>
+        public static readonly DependencyProperty PlaceholderProperty = DependencyProperty.RegisterAttached(
+            "Placeholder",
+            typeof(string),
+            typeof(TextBoxHelper),
+            new PropertyMetadata(string.Empty, OnPlaceholderChanged));
+
+        /// <summary>
+        ///     Vertical alignment for placeholder.
+        /// </summary>
+        public static readonly DependencyProperty PlaceholderBaselineProperty = DependencyProperty.RegisterAttached(
+            "PlaceholderBaseline",
+            typeof(AlignmentY),
+            typeof(TextBoxHelper),
+            new PropertyMetadata(AlignmentY.Center));
+
+        /// <summary>
+        ///     Property to store generated placeholder brush.
+        /// </summary>
+        public static readonly DependencyProperty PlaceholderBrushProperty = DependencyProperty.RegisterAttached(
+            "PlaceholderBrush",
+            typeof(Brush),
+            typeof(TextBoxHelper),
+            new PropertyMetadata(Brushes.Transparent));
+
+        /// <summary>
+        ///     Setter for AutoScrollProperty
+        /// </summary>
+        /// <param name="element"></param>
+        /// <param name="enabled"></param>
+        public static void SetAutoScroll(UIElement element, bool enabled) {
+            element.SetValue(AutoScrollProperty, enabled);
+        }
+
+        /// <summary>
+        ///     Getter for AutoScrollProperty
+        /// </summary>
+        /// <param name="element"></param>
+        /// <returns></returns>
+        public static bool GetAutoScroll(UIElement element) {
+            return (bool)element.GetValue(AutoScrollProperty);
+        }
+
+        /// <summary>
+        ///     Triggered when AutoScroll property changed.
+        /// </summary>
+        /// <param name="d"></param>
+        /// <param name="e"></param>
+        public static void OnAutoScrollChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
+            var textBox = d as TextBox;
+            if (textBox == null) return;
+
+            textBox.SelectionChanged -= UpdateScrollOnSelectionChanged;
+            if ((bool)e.NewValue == true) {
+                textBox.SelectionChanged += UpdateScrollOnSelectionChanged;
+            }
+        }
+
+        /// <summary>
+        ///     Triggered when placeholder changed.
+        /// </summary>
+        /// <param name="d"></param>
+        /// <param name="e"></param>
+        private static void OnPlaceholderChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
+            var textBox = d as TextBox;
+            if (textBox != null) textBox.Loaded += OnTextLoaded;
+        }
+
+        /// <summary>
+        ///     Setter for Placeholder property
+        /// </summary>
+        /// <param name="element"></param>
+        /// <param name="value"></param>
+        public static void SetPlaceholder(UIElement element, string value) {
+            element.SetValue(PlaceholderProperty, value);
+        }
+
+        /// <summary>
+        ///     Getter for Placeholder property
+        /// </summary>
+        /// <param name="element"></param>
+        /// <returns></returns>
+        public static string GetPlaceholder(UIElement element) {
+            return (string)element.GetValue(PlaceholderProperty);
+        }
+
+        /// <summary>
+        ///     Setter for PlaceholderBaseline property
+        /// </summary>
+        /// <param name="element"></param>
+        /// <param name="align"></param>
+        public static void SetPlaceholderBaseline(UIElement element, AlignmentY align) {
+            element.SetValue(PlaceholderBaselineProperty, align);
+        }
+
+        /// <summary>
+        ///     Setter for PlaceholderBaseline property.
+        /// </summary>
+        /// <param name="element"></param>
+        /// <returns></returns>
+        public static AlignmentY GetPlaceholderBaseline(UIElement element) {
+            return (AlignmentY)element.GetValue(PlaceholderBaselineProperty);
+        }
+
+        /// <summary>
+        ///     Setter for PlaceholderBrush property.
+        /// </summary>
+        /// <param name="element"></param>
+        /// <param name="value"></param>
+        public static void SetPlaceholderBrush(UIElement element, Brush value) {
+            element.SetValue(PlaceholderBrushProperty, value);
+        }
+
+        /// <summary>
+        ///     Getter for PlaceholderBrush property.
+        /// </summary>
+        /// <param name="element"></param>
+        /// <returns></returns>
+        public static Brush GetPlaceholderBrush(UIElement element) {
+            return (Brush)element.GetValue(PlaceholderBrushProperty);
+        }
+
+        /// <summary>
+        ///     Set placeholder as background when TextBox was loaded.
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private static void OnTextLoaded(object sender, RoutedEventArgs e) {
+            var textBox = sender as TextBox;
+            if (textBox == null) return;
+
+            Label placeholder = new Label();
+            placeholder.Content = textBox.GetValue(PlaceholderProperty);
+
+            VisualBrush brush = new VisualBrush();
+            brush.AlignmentX = AlignmentX.Left;
+            brush.AlignmentY = GetPlaceholderBaseline(textBox);
+            brush.TileMode = TileMode.None;
+            brush.Stretch = Stretch.None;
+            brush.Opacity = 0.3;
+            brush.Visual = placeholder;
+
+            textBox.SetValue(PlaceholderBrushProperty, brush);
+            textBox.Background = brush;
+            textBox.TextChanged += UpdatePlaceholder;
+            UpdatePlaceholder(textBox, null);
+        }
+
+        /// <summary>
+        ///     Dynamically hide/show placeholder.
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private static void UpdatePlaceholder(object sender, RoutedEventArgs e) {
+            var textBox = sender as TextBox;
+            if (string.IsNullOrEmpty(textBox.Text)) {
+                textBox.Background = textBox.GetValue(PlaceholderBrushProperty) as Brush;
+            } else {
+                textBox.Background = Brushes.Transparent;
+            }
+        }
+
+        /// <summary>
+        ///     
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private static void UpdateScrollOnSelectionChanged(object sender, RoutedEventArgs e) {
+            var textBox = sender as TextBox;
+            if (textBox != null && textBox.IsFocused) {
+                if (Mouse.LeftButton == MouseButtonState.Pressed && textBox.SelectionLength > 0) {
+                    var p = Mouse.GetPosition(textBox);
+                    if (p.X <= 8) {
+                        textBox.LineLeft();
+                    } else if (p.X >= textBox.ActualWidth - 8) {
+                        textBox.LineRight();
+                    }
+
+                    if (p.Y <= 8) {
+                        textBox.LineUp();
+                    } else if (p.Y >= textBox.ActualHeight - 8) {
+                        textBox.LineDown();
+                    }
+                } else {
+                    var rect = textBox.GetRectFromCharacterIndex(textBox.CaretIndex);
+                    if (rect.Left <= 0) {
+                        textBox.ScrollToHorizontalOffset(textBox.HorizontalOffset + rect.Left);
+                    } else if (rect.Right >= textBox.ActualWidth) {
+                        textBox.ScrollToHorizontalOffset(textBox.HorizontalOffset + rect.Right);
+                    }
+
+                    if (rect.Top <= 0) {
+                        textBox.ScrollToVerticalOffset(textBox.VerticalOffset + rect.Top);
+                    } else if (rect.Bottom >= textBox.ActualHeight) {
+                        textBox.ScrollToVerticalOffset(textBox.VerticalOffset + rect.Bottom);
+                    }
+                    
+                }
+            }
+        }
+    }
+}
diff --git a/SourceGit/Resources/Styles/TextBox.xaml b/SourceGit/Resources/Styles/TextBox.xaml
index 728587fd..91578281 100644
--- a/SourceGit/Resources/Styles/TextBox.xaml
+++ b/SourceGit/Resources/Styles/TextBox.xaml
@@ -1,114 +1,118 @@
-<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
-    <!-- 错误Tooltip -->
-    <ControlTemplate x:Key="Template.Validation.Tooltip" TargetType="{x:Type ToolTip}">
-        <Border x:Name="Root" Margin="5,0,0,0" Opacity="0" Padding="0,0,20,20" RenderTransformOrigin="0,0">
-            <Border.RenderTransform>
-                <TranslateTransform x:Name="xform" X="-25" />
-            </Border.RenderTransform>
-            <VisualStateManager.VisualStateGroups>
-                <VisualStateGroup x:Name="OpenStates">
-                    <VisualStateGroup.Transitions>
-                        <VisualTransition GeneratedDuration="0" />
-                        <VisualTransition GeneratedDuration="0:0:0.2" To="Open">
-                            <Storyboard>
-                                <DoubleAnimation Duration="0:0:0.2" To="0" Storyboard.TargetProperty="X" Storyboard.TargetName="xform">
-                                    <DoubleAnimation.EasingFunction>
-                                        <BackEase Amplitude=".3" EasingMode="EaseOut" />
-                                    </DoubleAnimation.EasingFunction>
-                                </DoubleAnimation>
-                                <DoubleAnimation Duration="0:0:0.2" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="Root" />
-                            </Storyboard>
-                        </VisualTransition>
-                    </VisualStateGroup.Transitions>
-                    <VisualState x:Name="Closed">
-                        <Storyboard>
-                            <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="Root" />
-                        </Storyboard>
-                    </VisualState>
-                    <VisualState x:Name="Open">
-                        <Storyboard>
-                            <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="X" Storyboard.TargetName="xform" />
-                            <DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="Root" />
-                        </Storyboard>
-                    </VisualState>
-                </VisualStateGroup>
-            </VisualStateManager.VisualStateGroups>
-            <FrameworkElement.Effect>
-                <DropShadowEffect  BlurRadius="11" ShadowDepth="6" Opacity="0.4" />
-            </FrameworkElement.Effect>
-            <Border Background="#FFDC000C" BorderThickness="1" BorderBrush="#FFBC000C">
-                <TextBlock Foreground="White" MaxWidth="250" Margin="8,4,8,4" TextWrapping="Wrap" Text="{Binding [0].ErrorContent}" UseLayoutRounding="false" />
-            </Border>
-        </Border>
-    </ControlTemplate>
-
-    <!-- 验证错误模板 -->
-    <ControlTemplate x:Key="Template.Validation.Error">
-        <AdornedElementPlaceholder x:Name="Target">
-            <Border BorderBrush="#FFDB000C" BorderThickness="1" x:Name="root">
-                <ToolTipService.ToolTip>
-                    <ToolTip x:Name="validationTooltip" 
-                            Placement="Right" 
-                            PlacementTarget="{Binding RelativeSource={RelativeSource TemplatedParent}}"
-                            Template="{StaticResource Template.Validation.Tooltip}"
-                            Style="{x:Null}"/>
-                </ToolTipService.ToolTip>
-                <Grid Background="Transparent" HorizontalAlignment="Right" Height="12" Width="12" Margin="1,-4,-4,0" VerticalAlignment="Top">
-                    <Path Data="M 1,0 L6,0 A 2,2 90 0 1 8,2 L8,7 z" Fill="#FFDC000C" Margin="1,3,0,0" />
-                </Grid>
-            </Border>
-        </AdornedElementPlaceholder>
-
-        <ControlTemplate.Triggers>
-            <MultiDataTrigger>
-                <MultiDataTrigger.Conditions>
-                    <Condition Binding="{Binding ElementName=Target, Path=AdornedElement.IsKeyboardFocusWithin, Mode=OneWay}" Value="True" />
-                    <Condition Binding="{Binding ElementName=Target, Path=AdornedElement.(Validation.HasError), Mode=OneWay}" Value="True" />
-                </MultiDataTrigger.Conditions>
-                <Setter TargetName="validationTooltip" Property="IsOpen" Value="True"/>
-            </MultiDataTrigger>
-        </ControlTemplate.Triggers>
-    </ControlTemplate>
-    
-    <!-- 修改默认 -->
-    <Style TargetType="{x:Type TextBox}">
-        <Setter Property="SnapsToDevicePixels" Value="True"/>
-        <Setter Property="VerticalAlignment" Value="Center"/>
-        <Setter Property="VerticalContentAlignment" Value="Center"/>
-        <Setter Property="TextElement.Foreground" Value="{DynamicResource Brush.FG}"/>
-        <Setter Property="CaretBrush" Value="{DynamicResource Brush.FG}"/>
-        <Setter Property="Background" Value="Transparent"/>
-        <Setter Property="BorderBrush" Value="{DynamicResource Brush.Border1}"/>
-        <Setter Property="Validation.ErrorTemplate" Value="{StaticResource Template.Validation.Error}"/>
-
-        <Setter Property="Template">
-            <Setter.Value>
-                <ControlTemplate TargetType="{x:Type TextBox}">
-                    <Border x:Name="Border" 
-                            Background="{TemplateBinding Background}"
-                            SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
-                            BorderThickness="{TemplateBinding BorderThickness}"
-                            BorderBrush="{TemplateBinding BorderBrush}">
-                        <ScrollViewer x:Name="PART_ContentHost"
-                                      Margin="{TemplateBinding Padding}"
-                                      VerticalAlignment="Center"
-                                      Background="{x:Null}"
-                                      BorderThickness="0"
-                                      IsTabStop="False"
-                                      SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
-                    </Border>
-                        
-                    <ControlTemplate.Triggers>
-                        <Trigger Property="IsMouseOver" Value="true">
-                            <Setter TargetName="Border" Property="BorderBrush" Value="{DynamicResource Brush.Accent1}"/>
-                        </Trigger>
-                        <Trigger Property="AcceptsReturn" Value="True">
-                            <Setter TargetName="PART_ContentHost" Property="VerticalAlignment" Value="Top"/>
-                        </Trigger>
-                    </ControlTemplate.Triggers>
-                </ControlTemplate>
-            </Setter.Value>
-        </Setter>
-    </Style>
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    xmlns:helpers="clr-namespace:SourceGit.Helpers">
+    
+    <!-- 错误Tooltip -->
+    <ControlTemplate x:Key="Template.Validation.Tooltip" TargetType="{x:Type ToolTip}">
+        <Border x:Name="Root" Margin="5,0,0,0" Opacity="0" Padding="0,0,20,20" RenderTransformOrigin="0,0">
+            <Border.RenderTransform>
+                <TranslateTransform x:Name="xform" X="-25" />
+            </Border.RenderTransform>
+            <VisualStateManager.VisualStateGroups>
+                <VisualStateGroup x:Name="OpenStates">
+                    <VisualStateGroup.Transitions>
+                        <VisualTransition GeneratedDuration="0" />
+                        <VisualTransition GeneratedDuration="0:0:0.2" To="Open">
+                            <Storyboard>
+                                <DoubleAnimation Duration="0:0:0.2" To="0" Storyboard.TargetProperty="X" Storyboard.TargetName="xform">
+                                    <DoubleAnimation.EasingFunction>
+                                        <BackEase Amplitude=".3" EasingMode="EaseOut" />
+                                    </DoubleAnimation.EasingFunction>
+                                </DoubleAnimation>
+                                <DoubleAnimation Duration="0:0:0.2" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="Root" />
+                            </Storyboard>
+                        </VisualTransition>
+                    </VisualStateGroup.Transitions>
+                    <VisualState x:Name="Closed">
+                        <Storyboard>
+                            <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="Root" />
+                        </Storyboard>
+                    </VisualState>
+                    <VisualState x:Name="Open">
+                        <Storyboard>
+                            <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="X" Storyboard.TargetName="xform" />
+                            <DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="Root" />
+                        </Storyboard>
+                    </VisualState>
+                </VisualStateGroup>
+            </VisualStateManager.VisualStateGroups>
+            <FrameworkElement.Effect>
+                <DropShadowEffect  BlurRadius="11" ShadowDepth="6" Opacity="0.4" />
+            </FrameworkElement.Effect>
+            <Border Background="#FFDC000C" BorderThickness="1" BorderBrush="#FFBC000C">
+                <TextBlock Foreground="White" MaxWidth="250" Margin="8,4,8,4" TextWrapping="Wrap" Text="{Binding [0].ErrorContent}" UseLayoutRounding="false" />
+            </Border>
+        </Border>
+    </ControlTemplate>
+
+    <!-- 验证错误模板 -->
+    <ControlTemplate x:Key="Template.Validation.Error">
+        <AdornedElementPlaceholder x:Name="Target">
+            <Border BorderBrush="#FFDB000C" BorderThickness="1" x:Name="root">
+                <ToolTipService.ToolTip>
+                    <ToolTip x:Name="validationTooltip" 
+                            Placement="Right" 
+                            PlacementTarget="{Binding RelativeSource={RelativeSource TemplatedParent}}"
+                            Template="{StaticResource Template.Validation.Tooltip}"
+                            Style="{x:Null}"/>
+                </ToolTipService.ToolTip>
+                <Grid Background="Transparent" HorizontalAlignment="Right" Height="12" Width="12" Margin="1,-4,-4,0" VerticalAlignment="Top">
+                    <Path Data="M 1,0 L6,0 A 2,2 90 0 1 8,2 L8,7 z" Fill="#FFDC000C" Margin="1,3,0,0" />
+                </Grid>
+            </Border>
+        </AdornedElementPlaceholder>
+
+        <ControlTemplate.Triggers>
+            <MultiDataTrigger>
+                <MultiDataTrigger.Conditions>
+                    <Condition Binding="{Binding ElementName=Target, Path=AdornedElement.IsKeyboardFocusWithin, Mode=OneWay}" Value="True" />
+                    <Condition Binding="{Binding ElementName=Target, Path=AdornedElement.(Validation.HasError), Mode=OneWay}" Value="True" />
+                </MultiDataTrigger.Conditions>
+                <Setter TargetName="validationTooltip" Property="IsOpen" Value="True"/>
+            </MultiDataTrigger>
+        </ControlTemplate.Triggers>
+    </ControlTemplate>
+    
+    <!-- 修改默认 -->
+    <Style TargetType="{x:Type TextBox}">
+        <Setter Property="SnapsToDevicePixels" Value="True"/>
+        <Setter Property="VerticalAlignment" Value="Center"/>
+        <Setter Property="VerticalContentAlignment" Value="Center"/>
+        <Setter Property="TextElement.Foreground" Value="{DynamicResource Brush.FG}"/>
+        <Setter Property="CaretBrush" Value="{DynamicResource Brush.FG}"/>
+        <Setter Property="Background" Value="Transparent"/>
+        <Setter Property="BorderBrush" Value="{DynamicResource Brush.Border1}"/>
+        <Setter Property="Validation.ErrorTemplate" Value="{StaticResource Template.Validation.Error}"/>
+        <Setter Property="helpers:TextBoxHelper.AutoScroll" Value="True"/>
+
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="{x:Type TextBox}">
+                    <Border x:Name="Border" 
+                            Background="{TemplateBinding Background}"
+                            SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
+                            BorderThickness="{TemplateBinding BorderThickness}"
+                            BorderBrush="{TemplateBinding BorderBrush}">
+                        <ScrollViewer x:Name="PART_ContentHost"
+                                      Margin="{TemplateBinding Padding}"
+                                      VerticalAlignment="Center"
+                                      Background="Transparent"
+                                      BorderThickness="0"
+                                      IsTabStop="False"
+                                      CanContentScroll="False"
+                                      SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
+                    </Border>
+                        
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="IsMouseOver" Value="true">
+                            <Setter TargetName="Border" Property="BorderBrush" Value="{DynamicResource Brush.Accent1}"/>
+                        </Trigger>
+                        <Trigger Property="AcceptsReturn" Value="True">
+                            <Setter TargetName="PART_ContentHost" Property="VerticalAlignment" Value="Top"/>
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
 </ResourceDictionary>
\ No newline at end of file
diff --git a/SourceGit/SourceGit.csproj b/SourceGit/SourceGit.csproj
index b538fee1..ac32ebc3 100644
--- a/SourceGit/SourceGit.csproj
+++ b/SourceGit/SourceGit.csproj
@@ -1,18 +1,18 @@
-<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
-    <PropertyGroup>
-        <TargetFramework>net461</TargetFramework>
-        <OutputType>WinExe</OutputType>
-        <UseWPF>true</UseWPF>
-        <UseWindowsForms>true</UseWindowsForms>
-        <ApplicationIcon>App.ico</ApplicationIcon>
-        <Company>sourcegit</Company>
-        <Description>OpenSource GIT client for Windows</Description>
-        <Copyright>Copyright © sourcegit 2020. All rights reserved.</Copyright>
-        <ApplicationManifest>App.manifest</ApplicationManifest>
-        <Version>2.0.0-preview</Version>
-        <PackageLicenseExpression>MIT</PackageLicenseExpression>
-    </PropertyGroup>
-    <ItemGroup>
-        <Resource Include="App.ico" />
-    </ItemGroup>
+<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
+    <PropertyGroup>
+        <TargetFramework>net46</TargetFramework>
+        <OutputType>WinExe</OutputType>
+        <UseWPF>true</UseWPF>
+        <UseWindowsForms>true</UseWindowsForms>
+        <ApplicationIcon>App.ico</ApplicationIcon>
+        <Company>sourcegit</Company>
+        <Description>OpenSource GIT client for Windows</Description>
+        <Copyright>Copyright © sourcegit 2020. All rights reserved.</Copyright>
+        <ApplicationManifest>App.manifest</ApplicationManifest>
+        <Version>2.0.0-preview</Version>
+        <PackageLicenseExpression>MIT</PackageLicenseExpression>
+    </PropertyGroup>
+    <ItemGroup>
+        <Resource Include="App.ico" />
+    </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/SourceGit/UI/WorkingCopy.xaml b/SourceGit/UI/WorkingCopy.xaml
index 6d4b735d..c4957829 100644
--- a/SourceGit/UI/WorkingCopy.xaml
+++ b/SourceGit/UI/WorkingCopy.xaml
@@ -343,8 +343,7 @@
                 ScrollViewer.HorizontalScrollBarVisibility="Disabled"
                 ScrollViewer.VerticalScrollBarVisibility="Auto"
                 helpers:TextBoxHelper.Placeholder="Enter commit message"
-                helpers:TextBoxHelper.PlaceholderBaseline="Top"
-                TextChanged="CommitMessageChanged">
+                helpers:TextBoxHelper.PlaceholderBaseline="Top">
                 <TextBox.Text>
                     <Binding ElementName="me" Path="CommitMessage" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged">
                         <Binding.ValidationRules>
diff --git a/SourceGit/UI/WorkingCopy.xaml.cs b/SourceGit/UI/WorkingCopy.xaml.cs
index 4dd0ad48..6e0345b8 100644
--- a/SourceGit/UI/WorkingCopy.xaml.cs
+++ b/SourceGit/UI/WorkingCopy.xaml.cs
@@ -729,10 +729,6 @@ namespace SourceGit.UI {
             e.Handled = true;
         }
 
-        private void CommitMessageChanged(object sender, TextChangedEventArgs e) {
-            (sender as TextBox).ScrollToEnd();
-        }
-
         private void StartAmend(object sender, RoutedEventArgs e) {
             var commits = Repo.Commits("-n 1");
             if (commits.Count == 0) {