Silverlight 3:ListBox DataTemplate Horizo​​ntalAlignment

Question

我有一个ListBox,它的ItemTemplate绑定到DataTemplate.我的问题是我无法将模板中的元素拉伸到ListBox的整个宽度.

<ListBox x:Name="listPeople" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" 
    Margin="0,0,0,0" Background="{x:Null}" SelectionMode="Extended" Grid.Row="1" 
    ItemTemplate="{StaticResource PersonViewModel.BrowserDataTemplate}" 
    ItemsSource="{Binding Mode=OneWay, Path=SearchResults}" >
</ListBox>

<DataTemplate x:Key="PersonViewModel.BrowserDataTemplate">
   <ListBoxItem HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
     <Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin="5,5,5,5">
       <Border Opacity=".1" x:Name="itemBorder"  Background="#FF000000"   
         HorizontalAlignment="Stretch" VerticalAlignment="Stretch" 
         CornerRadius="5,5,5,5" MinWidth="100" Height="50"/>
      </Grid>
   </ListBoxItem>
</DataTemplate>

如您所见,我在网格中添加了一个边框以指示模板的宽度.我的目标是看到此边框扩展到列表框的整个宽度.目前它的宽度由其内容或MinWidth决定,这是目前保持可见的唯一内容.

Answer 1

我花了一个小时试图解决这个问题.非常非常令人沮丧.您不必覆盖ListBoxItem的整个默认样式.我无法让这个工作.最后,我通过简单地覆盖ListBox.ItemContainerStyle部分中的Horizo​​ntalContentAlignment属性来解决问题,例如:

            <ListBox x:Name="ClassList" ItemsSource="{Binding LineClasses}"
                     ScrollViewer.VerticalScrollBarVisibility="Visible"
                     SelectionMode="Extended"
                     ScrollViewer.HorizontalScrollBarVisibility="Hidden" HorizontalContentAlignment="Stretch"
                     HorizontalAlignment="Stretch" Loaded="ClassList_Loaded"
                     VerticalAlignment="Stretch" Grid.Row="0">
                <ListBox.ItemContainerStyle>
                    <Style TargetType="ListBoxItem">
                        <Setter Property="HorizontalContentAlignment" Value="Stretch"></Setter>
                    </Style>
                </ListBox.ItemContainerStyle>
                    <ListBox.ItemTemplate>

                    <DataTemplate>
                        <Border BorderBrush="Black" CornerRadius="3" Background="#FFE88D34"
                            BorderThickness="1" HorizontalAlignment="Stretch" >
                            <Grid Background="Transparent" HorizontalAlignment="Stretch" >
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="*" />
                                </Grid.ColumnDefinitions>
                                <TextBlock 
                                    Grid.Column="0" HorizontalAlignment="Stretch"
                                    Margin="2"                                   
                                    FontSize="10"
                                    Text="{Binding DisplayClassNm}"/>
                            </Grid>

                        </Border>
                    </DataTemplate>
                </ListBox.ItemTemplate>

这对我有用.

迈尔斯

Answer 2

为ListBox创建数据模板时,不应该使用incldue <ListBoxItem>.DataTemplate的内容将放在生成的容器中.您可以使用ItemContainerStyle控制该容器的构造方式.

ListBoxItem的默认控件样式默认用于定义ItemContainerStyle.此样式将ListBoxItem.Horizo​​ntalContentAlignment属性设置为"Left".注意ContentPresenter如何将其Horizo​​ntalAlignment绑定到此属性.

您需要覆盖绑定到ListBox时生成的ListBoxItem容器的样式.这可以通过设置ItemContainerStyle来完成.将Horizo​​ntalContentAlignment属性设置为"Stretch".

下面是默认的ListBoxItem样式.包括在内供参考.

<Style x:Key="ListBoxItemStyle1" TargetType="ListBoxItem">
            <Setter Property="Padding" Value="3"/>
            <Setter Property="HorizontalContentAlignment" Value="Left"/>
            <Setter Property="VerticalContentAlignment" Value="Top"/>
            <Setter Property="Background" Value="Transparent"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="TabNavigation" Value="Local"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="ListBoxItem">
                        <Grid Background="{TemplateBinding Background}">
                            <!-- VSM excluded for readability -->
                            <Rectangle x:Name="fillColor" Fill="#FFBADDE9" RadiusX="1" RadiusY="1" IsHitTestVisible="False" Opacity="0"/>
                            <Rectangle x:Name="fillColor2" Fill="#FFBADDE9" RadiusX="1" RadiusY="1" IsHitTestVisible="False" Opacity="0"/>
                            <ContentPresenter x:Name="contentPresenter" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" Content="{TemplateBinding Content}" ContentTemplate="{TemplateBinding ContentTemplate}"/>
                            <Rectangle x:Name="FocusVisualElement" Stroke="#FF6DBDD1" StrokeThickness="1" RadiusX="1" RadiusY="1" Visibility="Collapsed"/>
                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>