WPF 自定义ScrollViwer

ScrollViewer自定义样式

ScrollViewer在各种列表、集合控件中广泛使用的基础组建，先看看效果图：

如上图，ScrollViewer简单来说分两部分，一个横向的滚动条，一个垂直滚动条，两个样式、模板、功能都基本一样，他们都是ScrollBar。以垂直滚动条为例，分解一下，分解图：

• 1：向上滑动的按钮，用RepeatButton实现功能； 
• 2：上部分滑块，功能同1，也是一个RepeatButton来实现的； 
• 3：中间可拖动滑块，用一个Thumb来实现； 
• 4：下部分滑块，和5功能一样，向下滑动，用一个RepeatButton来实现； 
• 5：向下滑动的按钮，用RepeatButton实现功能；

上面实现的是一个标准的垂直滑动条ScrollBar组成，实际可用根据需求定制，实现不同效果的滑动效果。以上各部分的样式代码：

<Style x:Key="ScrollBarButton" TargetType="{x:Type RepeatButton}">
        <Setter Property="Background" Value="Transparent"></Setter>
        <Setter Property="Foreground" Value="{StaticResource TextForeground}"></Setter>
        <Setter Property="VerticalAlignment" Value="Center"></Setter>
        <Setter Property="HorizontalAlignment" Value="Center"></Setter>
        <Setter Property="Width" Value="auto"></Setter>
        <Setter Property="Height" Value="auto"></Setter>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type RepeatButton}">
                    <TextBlock x:Name="FIcon" FontSize="12" Text="{TemplateBinding local:ControlAttachProperty.FIcon}" Margin="1"
                               Style="{StaticResource FIcon}" />
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter Property="Foreground" Value="{StaticResource MouseOverForeground}" TargetName="FIcon"/>
                        </Trigger>
                        <Trigger Property="IsPressed" Value="True">
                            <Setter Property="Foreground" Value="{StaticResource PressedForeground}" TargetName="FIcon"/>
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Opacity" Value="0.5" TargetName="FIcon"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    <!--滚动条滑块两边按钮样式-->
    <Style x:Key="ScrollBarTrackButton" TargetType="{x:Type RepeatButton}">
        <Setter Property="Background" Value="Transparent"></Setter>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type RepeatButton}">
                    <Border Background="Transparent"></Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    <!--滚动条滑块样式-->
    <ControlTemplate x:Key="ThumbTemplate" TargetType="Thumb">
        <Grid>
            <Border  x:Name="Bg" CornerRadius="4" Margin="2" SnapsToDevicePixels="True" Background="{StaticResource ScrollBarForeround}">
                <!--<Border.Background>
                    <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">
                        <GradientStop Color="#C7C0C0" Offset="0.15"/>
                        <GradientStop Color="#AFA9A9" Offset=".5"/>
                        <GradientStop Color="#989494" Offset=".5"/>
                        <GradientStop Color="#858585" Offset="1"/>
                    </LinearGradientBrush>
                </Border.Background>-->
            </Border>
        </Grid>
        <ControlTemplate.Triggers>
            <Trigger Property="IsMouseOver" Value="True">
                <Setter Property="Background" Value="{StaticResource MouseOverForeground}" TargetName="Bg"></Setter>
            </Trigger>
            <Trigger Property="IsEnabled" Value="False">
                <Setter Property="Opacity" Value="0.5" TargetName="Bg"></Setter>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>

    <!--水平滚滚动条模板-->
    <ControlTemplate x:Key="HorizontalScrollBar" TargetType="{x:Type ScrollBar}">
        <Grid x:Name="HorizontalRoot" Height="{TemplateBinding Height}">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="Auto" />
                <ColumnDefinition Width="*" />
                <ColumnDefinition Width="Auto" />
            </Grid.ColumnDefinitions>
            <!--外部背景,好像不用更好看-->
            <!--<Border x:Name="Bg" Grid.Column="0" Grid.ColumnSpan="3" CornerRadius="0"  Opacity="0" Background="#858585"/>-->
            <!--内部背景-->
            <Border x:Name="BgInner" Grid.Column="1" Margin="0" SnapsToDevicePixels="True" Opacity="0.3"  CornerRadius="6" Background="{StaticResource ScrollBarBackground}"/>
            <!--左按钮-->

            <Border Grid.Column="0" VerticalAlignment="Center" HorizontalAlignment="Center">
                <RepeatButton  local:ControlAttachProperty.FIcon="�"  Style="{StaticResource ScrollBarButton}" x:Name="HorizontalSmallDecrease"
                                 IsTabStop="False" Interval="50" Margin="0,1,0,0" Command="ScrollBar.LineLeftCommand"/>
            </Border>
            <!--中间滑动区域-->
            <Track x:Name="PART_Track" IsDirectionReversed="False" Grid.Column="1">
                <!--左滑块-->
                <Track.DecreaseRepeatButton>
                    <RepeatButton x:Name="HorizontalLargeDecrease" Command="ScrollBar.PageLeftCommand"
                                      IsTabStop="False" Interval="50" Style="{DynamicResource ScrollBarTrackButton}" />
                </Track.DecreaseRepeatButton>
                <!--中间滑块 Margin="1" VerticalAlignment="Center" VerticalContentAlignment="Center" -->
                <Track.Thumb>
                    <Thumb Template="{StaticResource ThumbTemplate}" />
                </Track.Thumb>
                <!--右滑块-->
                <Track.IncreaseRepeatButton>
                    <RepeatButton x:Name="HorizontalLargeIncrease" Command="ScrollBar.PageRightCommand"
                                      IsTabStop="False"  Interval="50" Style="{DynamicResource ScrollBarTrackButton}" />
                </Track.IncreaseRepeatButton>
            </Track>
            <!--右按钮-->
            <Border Grid.Column="2" VerticalAlignment="Center" HorizontalAlignment="Center">
                <RepeatButton local:ControlAttachProperty.FIcon="�"  Style="{StaticResource ScrollBarButton}"
                                 IsTabStop="False" Interval="50" Margin="0,1,0,0" Command="ScrollBar.LineRightCommand"/>
            </Border>
        </Grid>
        <ControlTemplate.Triggers>
            <Trigger Property="IsMouseOver" Value="true">
                <Setter TargetName="BgInner" Property="Opacity" Value="0.5"/>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>

    <!--垂直滚滚动条模板-->
    <ControlTemplate x:Key="VerticalScrollBar" TargetType="{x:Type ScrollBar}">
        <Grid x:Name="VerticalRoot" Height="{TemplateBinding Height}">
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto" />
                <RowDefinition Height="*" />
                <RowDefinition Height="Auto" />
            </Grid.RowDefinitions>
            <!--外部背景,好像不用更好看-->
            <!--<Border x:Name="Bg" Grid.Row="0" Grid.RowSpan="3" CornerRadius="0" Opacity="0" Background="#858585"/>-->
            <!--内部背景-->
            <Border x:Name="BgInner" Grid.Row="1" Margin="0" CornerRadius="6" SnapsToDevicePixels ="True" Opacity="0.3"  Background="{StaticResource ScrollBarBackground}"/>
            <!--上按钮-->
            <Border Grid.Row="0" VerticalAlignment="Center" HorizontalAlignment="Center" x:Name="VerticalSmallDecrease">
                <RepeatButton local:ControlAttachProperty.FIcon="�"  Style="{StaticResource ScrollBarButton}"
                                 IsTabStop="False" Interval="50" Margin="0" Command="ScrollBar.LineUpCommand"/>
            </Border>
            <!--中间滑动区域-->
            <Track x:Name="PART_Track" IsDirectionReversed="true" Grid.Row="1">
                <!--上滑块-->
                <Track.DecreaseRepeatButton>
                    <RepeatButton x:Name="HorizontalLargeDecrease" Command="ScrollBar.PageUpCommand" 
                                      IsTabStop="False" Interval="50" Style="{DynamicResource ScrollBarTrackButton}" />
                </Track.DecreaseRepeatButton>
                <!--中间滑块-->
                <Track.Thumb>
                    <Thumb Template="{StaticResource ThumbTemplate}" MinHeight="10"/>
                </Track.Thumb>
                <!--下滑块-->
                <Track.IncreaseRepeatButton>
                    <RepeatButton x:Name="HorizontalLargeIncrease" Command="ScrollBar.PageDownCommand"
                                      IsTabStop="False" Interval="50" Style="{DynamicResource ScrollBarTrackButton}" />
                </Track.IncreaseRepeatButton>
            </Track>
            <!--下按钮-->
            <Border Grid.Row="2" VerticalAlignment="Center" HorizontalAlignment="Center" x:Name="VerticalSmallIncrease">
                <RepeatButton local:ControlAttachProperty.FIcon="�"  Style="{StaticResource ScrollBarButton}"
                                 IsTabStop="False" Interval="50" Margin="0" Command="ScrollBar.LineDownCommand"/>
            </Border>
        </Grid>
        <ControlTemplate.Triggers>
            <Trigger Property="IsMouseOver" Value="true">
                <Setter TargetName="BgInner" Property="Opacity" Value="0.5"/>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>

    <!--ScrollBar样式-->
    <Style x:Key="DefaultScrollBar" TargetType="{x:Type ScrollBar}">
        <Setter Property="SnapsToDevicePixels" Value="True" />
        <Setter Property="OverridesDefaultStyle" Value="true" />
        <Style.Triggers>
            <Trigger Property="Orientation" Value="Horizontal">
                <Setter Property="Template" Value="{StaticResource HorizontalScrollBar}" />
                <Setter Property="Height" Value="{StaticResource ScrollBarSize}" />
            </Trigger>
            <Trigger Property="Orientation" Value="Vertical">
                <Setter Property="Template" Value="{StaticResource VerticalScrollBar}" />
                <Setter Property="Width" Value="{StaticResource ScrollBarSize}" />
            </Trigger>
        </Style.Triggers>
    </Style>

<!--ScrollViewer样式-->
    <Style x:Key="DefaultScrollViewer" TargetType="{x:Type ScrollViewer}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ScrollViewer}">
                    <Grid x:Name="Grid" Background="{TemplateBinding Background}">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="*" x:Name="leftColumn" />
                            <ColumnDefinition Width="Auto" x:Name="rightColumn" />
                        </Grid.ColumnDefinitions>
                        <Grid.RowDefinitions>
                            <RowDefinition Height="*" />
                            <RowDefinition Height="Auto" />
                        </Grid.RowDefinitions>
                        <ScrollContentPresenter x:Name="PART_ScrollContentPresenter" CanContentScroll="{TemplateBinding CanContentScroll}"
                                                CanHorizontallyScroll="False" CanVerticallyScroll="False" ContentTemplate="{TemplateBinding ContentTemplate}"
                                                Content="{TemplateBinding Content}" Margin="{TemplateBinding Padding}"
                                                Grid.Row="0" Grid.Column="0" />
                        <!--垂直滚动条 -->
                        <ScrollBar x:Name="PART_VerticalScrollBar" AutomationProperties.AutomationId="VerticalScrollBar"
                                   ViewportSize="{TemplateBinding ViewportHeight}"
                                   Cursor="Arrow" Grid.Column="1" Maximum="{TemplateBinding ScrollableHeight}"
                                   Minimum="0" Grid.Row="0" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}"
                                   Value="{Binding VerticalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}"/>
                        <!--水平底部滚动条-->
                        <ScrollBar x:Name="PART_HorizontalScrollBar" AutomationProperties.AutomationId="HorizontalScrollBar"
                                   Cursor="Arrow" Grid.Column="0" Maximum="{TemplateBinding ScrollableWidth}"
                                   Minimum="0" Orientation="Horizontal" Grid.Row="1"
                                   Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}"
                                   Value="{Binding HorizontalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}"
                                   ViewportSize="{TemplateBinding ViewportWidth}" />
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

使用很简单，如果想通用，把上面定义的ScrollViewer设置为默认样式即可： 

<Style TargetType="{x:Type ScrollBar}" BasedOn="{StaticResource DefaultScrollBar}"></Style> 

<Style TargetType="{x:Type ScrollViewer}" BasedOn="{StaticResource DefaultScrollViewer}"></Style>