WPF自定义控件与样式(6)

WPF自定义控件与样式(6)-ScrollViewer与ListBox自定义样式

一．前言

　　申明：WPF自定义控件与样式是一个系列文章，前后是有些关联的，但大多是按照由简到繁的顺序逐步发布的等，若有不明白的地方可以参考本系列前面的文章，文末附有部分文章链接。

本文主要内容：

• ScrollViewer的样式拆解及基本样式定义；
• ListBox集合控件的样式定义；  

二．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：  

View Code

　　最后ScrollViewer的样式如下，其实就是两个  ScrollBar组成：

    <!--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>

三．ListBox样式定义

ListBox是最基础、常用的集合控件，效果：

ListBox的样式比较简单，包括两部分：

• ListBoxItem项的样式；
• ListBox的样式；

完整代码：  

<Style x:Key="DefaultListBoxItem" TargetType="{x:Type ListBoxItem}">
        <Setter Property="Foreground" Value="{StaticResource TextForeground}" />
        <Setter Property="HorizontalContentAlignment" Value="Stretch" />
        <!--<Setter Property="VerticalContentAlignment" Value="Center" />-->
        <Setter Property="MinHeight" Value="25" />
        <Setter Property="Margin" Value="0" />
        <Setter Property="Background" Value="Transparent" />
        <Setter Property="Padding" Value="3,0,0,0" />
        <Setter Property="SnapsToDevicePixels" Value="True" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ListBoxItem}">
                    <Border x:Name="Border" Background="{TemplateBinding Background}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}">
                        <ContentPresenter Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
                                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsSelected" Value="True">
                            <Setter TargetName="Border" Property="Background" Value="{StaticResource ItemSelectedBackground}" />
                            <Setter Property="Foreground" Value="{StaticResource ItemSelectedForeground}" />
                        </Trigger>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter TargetName="Border" Property="Background" Value="{StaticResource ItemMouseOverBackground}" />
                            <Setter Property="Foreground" Value="{StaticResource ItemMouseOverForeground}" />
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="False">
                            <Setter TargetName="Border" Property="Opacity" Value="{StaticResource DisableOpacity}" />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    <Style x:Key="DefaultListBox" TargetType="{x:Type ListBox}">
        <Setter Property="BorderBrush" Value="{StaticResource ControlBorderBrush}" />
        <Setter Property="Background" Value="{StaticResource ItemsContentBackground}" />
        <Setter Property="BorderThickness" Value="1" />
        <Setter Property="ItemContainerStyle" Value="{StaticResource DefaultListBoxItem}"></Setter>
        <Setter Property="SnapsToDevicePixels" Value="True" />
        <Setter Property="VirtualizingStackPanel.IsVirtualizing" Value="False"></Setter>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ListBox}">
                    <Border Name="Border" Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}">
                        <ScrollViewer>
                            <ItemsPresenter />
                        </ScrollViewer>
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsEnabled" Value="False">
                            <Setter TargetName="Border" Property="Opacity" Value="{StaticResource DisableOpacity}" />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

ListBox默认是支持虚拟化的，当加载大数据时需要开启虚拟化，或者定义一个虚拟化的样式：

    <!--支持虚拟化的ListBox-->
    <Style x:Key="VirtualListBox" TargetType="{x:Type ListBox}" BasedOn="{StaticResource DefaultListBox}">
        <Setter Property="ScrollViewer.CanContentScroll" Value="True" />
        <Setter Property="VirtualizingStackPanel.IsVirtualizing" Value="True"></Setter>
        <Setter Property="VirtualizingStackPanel.VirtualizationMode" Value="Recycling" />
        <Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="False" />
    </Style>

上面演示效果的代码示例：  

<ListBox Margin="5" SelectionMode="Multiple"  >
                <ListBoxItem  Style="{StaticResource RadioButtonListBoxItem}">男</ListBoxItem>
                <ListBoxItem  Style="{StaticResource RadioButtonListBoxItem}">女</ListBoxItem>
                <ListBoxItem  Style="{StaticResource RadioButtonListBoxItem}">其他</ListBoxItem>
                <CheckBox>2222333333333333333</CheckBox>
                <CheckBox>2222333333333333333</CheckBox>
                <CheckBox>2222333333333333333</CheckBox>
                <CheckBox>2222333333333333333</CheckBox>
                <CheckBox>2222333333333333333</CheckBox>
                <CheckBox>2222333333333333333</CheckBox>
                <CheckBox>2222333333333333333</CheckBox>
                <CheckBox>2222333333333333333</CheckBox>
                <TextBox Width="200"></TextBox>
                <ListBoxItem IsSelected="True">111</ListBoxItem>
            </ListBox>
            <ListBox Margin="5" Grid.Column="1">
                <ListBoxItem  Style="{StaticResource RadioButtonListBoxItem}">男</ListBoxItem>
                <ListBoxItem  Style="{StaticResource RadioButtonListBoxItem}">女</ListBoxItem>
                <ListBoxItem  Style="{StaticResource RadioButtonListBoxItem}">其他</ListBoxItem>
            </ListBox>

另外提供一个比较常用的需求，ListBox单选RadioButton效果样式，如上图右边的那个ListBox效果：  

   <Style x:Key="RadioButtonListBoxItem" TargetType="{x:Type ListBoxItem}" BasedOn="{StaticResource DefaultListBoxItem}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ListBoxItem}">
                    <Border x:Name="Border" Background="{TemplateBinding Background}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}">
                        <RadioButton  IsChecked="{Binding IsSelected,RelativeSource={RelativeSource TemplatedParent},Mode=TwoWay}">
                            <RadioButton.Content>
                                <ContentPresenter Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
                                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
                            </RadioButton.Content>
                        </RadioButton>
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsSelected" Value="True">
                            <Setter TargetName="Border" Property="Background" Value="{StaticResource ItemSelectedBackground}" />
                            <Setter Property="Foreground" Value="{StaticResource ItemSelectedForeground}" />
                        </Trigger>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter TargetName="Border" Property="Background" Value="{StaticResource ItemMouseOverBackground}" />
                            <Setter Property="Foreground" Value="{StaticResource ItemMouseOverForeground}" />
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="False">
                            <Setter TargetName="Border" Property="Opacity" Value="{StaticResource DisableOpacity}" />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>