WPF Expander 炫酷自定义Style

首先, 看一下效果图。

点我看视频教程

实现思路

1.PS处理两张选中得特效背景, 一张为主选择得效果图, 另外一张为次选择项得效果图。
![](https://img2020.cnblogs.com/blog/1161656/202003/1161656-20200325221915253-468522090.png)
![](https://img2020.cnblogs.com/blog/1161656/202003/1161656-20200325221923049-516705706.png)

图片资源定义

        <!--静态资源-->
        <ImageBrush x:Key="leftImage" ImageSource="/IndustrialMaterials;component/images/leftImage.png"/>
        <ImageBrush x:Key="leftImageSub" ImageSource="/IndustrialMaterials;component/images/leftImageSub.png"/>
        <ImageBrush x:Key="topImage" ImageSource="/IndustrialMaterials;component/images/topImage.png"/>

ToggleButton样式实现:

1.自定义Expander样式, Expander样式模板中, 主要分为两个部分, 1.ToggleButton 2.ContentPresenter

2.ToogleButton主要通过IsChecked进行触发器控制设置Background, 以下代码:

         <!--下拉列表样式-->
        <Style x:Key="ToggleButtonStyle" TargetType="{x:Type ToggleButton}">
            <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
            <Setter Property="Height" Value="80" />
            <Setter Property="HorizontalContentAlignment" Value="Right"/>
            <Setter Property="VerticalContentAlignment" Value="Center"/>
            <Setter Property="Padding" Value="10 10"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type ToggleButton}">
                        <Grid>
                            <Border x:Name="border2"   Background="{TemplateBinding Background}"  
                                    HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                     Margin="{TemplateBinding Padding}" 
                     VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
                                <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                     Margin="{TemplateBinding Padding}" 
                     RecognizesAccessKey="True" 
                     SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" 
                     VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                            </Border>
                        </Grid>

                        <ControlTemplate.Triggers>
                            <Trigger Property="IsPressed" Value="true">
                                <Setter Property="Background" Value="#FFd2e7f4" />
                            </Trigger>
                            <Trigger Property="IsChecked" Value="true">
                                <Setter Property="Background" TargetName="border2" Value="{StaticResource ResourceKey=leftImage}"/>
                            </Trigger>
                            <Trigger Property="IsChecked" Value="false">
                                <Setter Property="Background" TargetName="border2" Value="#191E36"/>
                            </Trigger>
                            <Trigger Property="IsEnabled" Value="false">
                                <Setter Property="Foreground" Value="White"/>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

Expander样式实现

        <Style x:Key="ExpanderStyle" TargetType="{x:Type Expander}">
            <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
            <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
            <Setter Property="VerticalContentAlignment" Value="Stretch"/>
            <Setter Property="BorderBrush" Value="Transparent"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type Expander}">
                        <DockPanel>
                            <ToggleButton x:Name="HeaderSite" ContentTemplate="{TemplateBinding HeaderTemplate}" 
                                              ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}" 
                                              Content="{TemplateBinding Header}" DockPanel.Dock="Top" 
                                              Foreground="{TemplateBinding Foreground}" 
                                              FontWeight="{TemplateBinding FontWeight}" 
                                              FontStyle="{TemplateBinding FontStyle}" FontStretch="{TemplateBinding FontStretch}" 
                                              FontSize="{TemplateBinding FontSize}" FontFamily="{TemplateBinding FontFamily}" 
                                              HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" 
                                              IsChecked="{Binding IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource 
                                    TemplatedParent}}" Margin="1" MinWidth="0" MinHeight="0" Padding="{TemplateBinding Padding}"
                                              Style="{StaticResource ToggleButtonStyle}"
                                              VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
                            <ContentPresenter x:Name="ExpandSite" DockPanel.Dock="Left" Focusable="false" 
                                                  HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                                                  Margin="{TemplateBinding Padding}" Visibility="Collapsed" 
                                                  VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                        </DockPanel>
                        <ControlTemplate.Triggers>
                            <Trigger Property="IsExpanded" Value="true">
                                <Setter Property="Visibility" TargetName="ExpandSite" Value="Visible"/>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

Expander引用样式部分代码: