继续聊WPF——Expander控件（2）

<Window x:Class="Expander_Sample2.Window1"  

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  

    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  

    Title="Window1" Height="300" Width="300">  

    <Window.Resources>  

        <!--  

        ToogleButton的模板，  

        因为要进和状态切换，故要用到ToggleButton控件  

        -->  

        <ControlTemplate x:Key="ToggleButtonTemp" TargetType="{x:Type ToggleButton}">  

            <Border x:Name="bd"  

                    BorderThickness="1"  

                    CornerRadius="1,1,1,1">  

                <Border.Background>  

                    <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">  

                        <GradientStop Color="LightGray" Offset="0"/>  

                        <GradientStop Color="White" Offset="1"/>  

                    </LinearGradientBrush>  

                </Border.Background>  

                <Border.BorderBrush>  

                    <LinearGradientBrush StartPoint="0,0" EndPoint="1,1">  

                        <GradientStop Color="Black" Offset="0"/>  

                        <GradientStop Color="Gray" Offset="1"/>  

                    </LinearGradientBrush>  

                </Border.BorderBrush>  

                <Path Margin="2,2,2,2" Fill="Black" x:Name="p"  

                      Data="M 0,0 L 4,5 L8,0 Z"  

                      HorizontalAlignment="Center"  

                      VerticalAlignment="Center"/>  

            </Border>  

            <ControlTemplate.Triggers>  

                <Trigger Property="IsMouseOver" Value="True">  

                    <Setter TargetName="bd" Property="Background">  

                        <Setter.Value>  

                            <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">  

                                <GradientStop Color="LightGreen" Offset="0"/>  

                                <GradientStop Color="White" Offset="1"/>  

                            </LinearGradientBrush>  

                        </Setter.Value>  

                    </Setter>  

                </Trigger>  

                <Trigger Property="IsChecked" Value="True">  

                    <Setter TargetName="p" Property="Data"  

                                Value="M0,5 L8,5 L4,0 Z"/>  

                </Trigger>  

                <Trigger Property="IsEnabled" Value="True">  

                    <Setter TargetName="bd" Property="BorderBrush" Value="Gray"/>  

                    <Setter TargetName="p" Property="Fill" Value="Gray"/>  

                </Trigger>  

            </ControlTemplate.Triggers>  

        </ControlTemplate>  

        <!-- 

            Expnder的样式 

        -->  

        <Style TargetType="{x:Type Expander}">  

            <Setter Property="Template">  

                <Setter.Value>  

                    <ControlTemplate TargetType="{x:Type Expander}">  

                        <Grid>  

                            <Grid.RowDefinitions>  

                                <RowDefinition Height="auto"/>  

                                <RowDefinition x:Name="gr" Height="0"/>  

                            </Grid.RowDefinitions>  

                            <BulletDecorator Background="DarkTurquoise" Grid.Row="0" VerticalAlignment="Center" >  

                                <BulletDecorator.Bullet>  

                                    <ToggleButton Margin="1,1,1,1"  Height="18" Width="18" Template="{StaticResource ToggleButtonTemp}"  

                                                  IsChecked="{Binding Path=IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"  

                                                  OverridesDefaultStyle="True"/>  

                                </BulletDecorator.Bullet>  

                                <ContentPresenter HorizontalAlignment="Center" Margin="1,1,1,1" ContentSource="Header"/>  

                            </BulletDecorator>  

                            <Border x:Name="scv" Background="LightGray" BorderThickness="1" BorderBrush="Black" Grid.Row="1" >  

                                <ContentPresenter Margin="0" ContentSource="Content"/>  

                            </Border>  

                        </Grid>  

                        <ControlTemplate.Triggers>  

                            <Trigger Property="IsExpanded" Value="True">  

                                <Setter TargetName="gr" Property="Height" Value="{Binding Path=DesiredSize/Height,ElementName=scv}"/>  

                            </Trigger>  

                        </ControlTemplate.Triggers>  

                    </ControlTemplate>  

                </Setter.Value>  

            </Setter>  

        </Style>  

    </Window.Resources>  

    <Grid>  

        <Expander Margin="10,10" Height="210" Width="130" OverridesDefaultStyle="True">  

            <Expander.Header>  

                <TextBlock Text="相见恨晚" FontWeight="Bold" FontSize="16"/>  

            </Expander.Header>  

            <TextBlock TextWrapping="Wrap">  

                如果相见不会太晚，我们就不会悲伤，和你堂堂的手牵手，过得好简单，  

                若我有天不见了，或许你会比较快乐，虽然有万般舍不得，也不愿看你难割舍   

                若我有天不在了。请你原谅我的困扰，虽然你给我的不算少，只是我没福气要就算是完美。  

            </TextBlock>  

        </Expander>  

    </Grid>  

</Window>