>
<Setter.Value>
<ControlTemplate>
<local:FButton FIcon="" Style="{StaticResource FButton_Transparency}" IsTabStop="False" FIconMargin="0"
local:ControlAttachProperty.IsClearTextButtonBehaviorEnabled="True" Command="local:ControlAttachProperty.ClearTextCommand"
CommandParameter="{Binding RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type TextBox}}}"
Margin="1,3,1,4" FIconSize="14" Foreground="{StaticResource TextForeground}" Cursor="Arrow"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
这里定义的是显示效果，清除TextBox内容的逻辑代码如何实现的呢？还是附加属性：
- ControlAttachProperty.IsClearTextButtonBehaviorEnabled="True" ：注入事件到当前Button
- Command="local:ControlAttachProperty.ClearTextCommand"：定义Fbutton的命令对象实例Command
- CommandParameter="{Binding RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type TextBox}}}"：把TextBox作为参数传入
逻辑代码如下，从代码不难看出，它是支持多种输入控件的内容清除的，也就是说该扩展功能可以轻松支持其他输入控件，第四节密码数据的清除也是这样使用的。
View Code
效果：
当然我们也可以自定义扩展其他功能，如：
<TextBox Width="200" Height="30" Margin="3" core:ControlAttachProperty.Watermark="查询关键词" IsEnabled="True">
<core:ControlAttachProperty.AttachContent>
<ControlTemplate>
<StackPanel Orientation="Horizontal">
<core:FButton FIcon="" Style="{StaticResource FButton_Transparency}" IsTabStop="False" FIconMargin="0"
FIconSize="18" Margin="1,1,2,3" Foreground="{StaticResource TextForeground}" Cursor="Arrow"/>
<core:FButton FIcon="" Style="{StaticResource FButton_Transparency}" IsTabStop="False" FIconMargin="0"
FIconSize="22" Foreground="{StaticResource TextForeground}" Cursor="Arrow"/>
</StackPanel>
</ControlTemplate>
</core:ControlAttachProperty.AttachContent>
</TextBox>
效果：
由上不难同时实现Label标签和清除文本内容的样式：
<!--TextBox包含附加属性Label，以及ClearText按钮的样式-->
<Style TargetType="{x:Type TextBox}" x:Key="LabelClearButtonTextBox" BasedOn="{StaticResource DefaultTextBox}">
<Setter Property="local:ControlAttachProperty.LabelTemplate" >
<Setter.Value>
<ControlTemplate TargetType="ContentControl">
<Border Width="60" Background="{StaticResource TextLabelBackground}">
<TextBlock VerticalAlignment="Center" HorizontalAlignment="Right" Margin="3" Text="{TemplateBinding Content}"></TextBlock>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="local:ControlAttachProperty.AttachContent">
<Setter.Value>
<ControlTemplate>
<local:FButton FI 