我希望ListItems以其橙色背景擴展為Listbox的整個寬度。目前它們只與FirstName + LastName一樣寬。我已將每個元素設(shè)置為：HorizontalAlignment =“Stretch”。我希望ListboxItems的背景隨著用戶拉伸列表框而擴展，因此我不想輸入絕對值。我需要做什么才能使ListBoxItems的背景顏色填充ListBox的寬度？<Window x:Class="TestListBoxSelectedItemStyle.Window1"     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     xmlns:local="clr-namespace:TestListBoxSelectedItemStyle"     Title="Window1" Height="300" Width="300">     <Window.Resources>         <local:CustomerViewModel x:Key="TheDataProvider"/>         <DataTemplate x:Key="CustomerItemTemplate">             <Border CornerRadius="5" Background="Orange" HorizontalAlignment="Stretch" Padding="5" Margin="3">                 <StackPanel Orientation="Horizontal" HorizontalAlignment="Stretch" Width="Auto">                     <TextBlock HorizontalAlignment="Stretch">                     <TextBlock.Text>                         <MultiBinding StringFormat="{}{0} {1}">                             <Binding Path="FirstName"/>                             <Binding Path="LastName"/>                         </MultiBinding>                     </TextBlock.Text>                     </TextBlock>                 </StackPanel>             </Border>         </DataTemplate>     </Window.Resources>     <Grid>         <ListBox ItemsSource="{Binding Path=GetAllCustomers, Source={StaticResource TheDataProvider}}"                  ItemTemplate="{StaticResource CustomerItemTemplate}"/>     </Grid></Window>