将自定义依赖属性绑定到自定义 WPF 样式

Question

我在设计继承的 Expander 时遇到了问题。我的意图是在切换按钮和默认扩展器标题中的文本后面有一个进度条。

我有这个 XAML 代码，它在标题中提供了进度条。这是一种自定义样式。

<Style x:Key="CurrentScanExpanderStyle" TargetType="{x:Type local:ProgressExpander}">
        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
        <Setter Property="Background" Value="Transparent"/>
        <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 local:ProgressExpander}">
                    <Border SnapsToDevicePixels="true" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="3">
                        <DockPanel>
                            <Grid DockPanel.Dock="Top">
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="*"/>
                                </Grid.ColumnDefinitions>
                                <ProgressBar Name="ProgressBar"/>
                                <ToggleButton FontFamily="{TemplateBinding FontFamily}" FontSize="{TemplateBinding FontSize}" FontStretch="{TemplateBinding FontStretch}" FontStyle="{TemplateBinding FontStyle}" FontWeight="{TemplateBinding FontWeight}" Foreground="{TemplateBinding Foreground}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" FocusVisualStyle="{StaticResource ExpanderHeaderFocusVisual}" Margin="1" MinHeight="0" MinWidth="0" x:Name="HeaderSite" Style="{StaticResource ExpanderDownHeaderStyle}" IsChecked="{Binding Path=IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Content="{TemplateBinding Header}" ContentTemplate="{TemplateBinding HeaderTemplate}" ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}"/>
                            </Grid>
                            <ContentPresenter Focusable="false" Visibility="Collapsed" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" x:Name="ExpandSite" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" DockPanel.Dock="Bottom"/>
                        </DockPanel>
                    </Border>
                    <ControlTemplate.Triggers>
                        <!-- Triggers haven't changed from the default -->
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

这工作正常，但我无法绑定控制进度百分比的自定义依赖项属性。

    public class ProgressExpander : Expander
{
    static ProgressExpander()
    {
        DefaultStyleKeyProperty.OverrideMetadata(typeof(ProgressExpander), new FrameworkPropertyMetadata(typeof(ProgressExpander)));
    }       



    public int Progress
    {
        get { return (int)GetValue(ProgressProperty); }
        set { SetValue(ProgressProperty, value); }
    }

    // Using a DependencyProperty as the backing store for Progress.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty ProgressProperty =
        DependencyProperty.Register("Progress", typeof(int), typeof(ProgressExpander), new UIPropertyMetadata(0));


}

这是窗口内的代码：

            <local:ProgressExpander Grid.Row="1" Header="Current Scan" ExpandDirection="Down" x:Name="currentScanExpander" Style="{DynamicResource CurrentScanExpanderStyle}">
                <Canvas Background="SkyBlue" 
                        Name="currentScanCanvas"
                        Height="{Binding ElementName=currentScanExpander, Path=ActualWidth}"
                        />
            </local:ProgressExpander>

我不确定如何将此依赖属性progress绑定到样式内ProgressBar中的进度值。

任何帮助将不胜感激。

Answer 1

在样式中，我们可以使用标准的Binding和RelativeSource来设置属性。

<ProgressBar Name="ProgressBar"
             Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Progress}"
             Minimum="0"
             Maximum="100" />

然后，我们只需在窗口中添加 Progress="50" 或绑定到其他位置。

您还需要将 Button 的背景设置为透明，或更改某种布局方式才能看到它。