Wpf Cómo cambiar el cuadro de lista ItemspanelTemplate usando Trigger

listbox itemtemplate wpf

Question

Necesito establecer la propiedad ItemsPanelTemplate de un ListBox basado en DependencyProperty en el control. ¿Cómo uso DataTemplateSelector para hacer eso?

Tengo algo como:

<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<!-- Here I need to replace with either a StackPanel or a wrap panel-->
</ItemsPanelTemplate>
</ListBox.ItemsPanel>

Aquí ( ItemsPanelTemplate Selector en wpf? ) Es un enlace con una Pregunta similar . A continuación está mi código pero no está funcionando:

<Window x:Class="MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<XmlDataProvider x:Key="myXmlDataBase" XPath="/myXmlData">
<x:XData>
<myXmlData xmlns="">
<Item Name = "CoverSheet" SNo="1" Type="GrpBX" Image="C:/Work/00288511851128436163/N12201_0003_003/00000003.tif"/>
<Item Name = "HCFA" SNo="2" Type="GrpBX" Image="C:/Work/00288511851128436163/N12201_0003_003/00000004.tif"/>
<Item Name = "HCFA" SNo="3" Type="GrpBX" Image="C:/Work/00288511851128436163/N12201_0003_003/00000004.tif"/>
<Item Name = "HCFA" SNo="4" Type="GrpBX" Image="C:/Work/00288511851128436163/N12201_0003_003/00000004.tif"/>
<Item Name = "HCFA" SNo="5" Type="GrpBX" Image="C:/Work/00288511851128436163/N12201_0003_003/00000004.tif"/>
<Item Name = "HCFA" SNo="6" Type="GrpBX" Image="C:/Work/00288511851128436163/N12201_0003_003/00000004.tif"/>
<Item Name = "HCFA_CC" SNo="7" Type="GrpBX" Image="C:/Work/00288511851128436163/N12201_0003_003/00000005.tif"/>
<Item Name = "FrontPage" SNo="8" Type="GrpBX" Image="C:/Work/00288511851128436163/N12201_0003_003/N12201_0003_003I00.tif"/>
</myXmlData>
</x:XData>
</XmlDataProvider>
</Window.Resources>
<DockPanel>
<ListBox Name="lv" ItemsSource="{Binding Source={StaticResource myXmlDataBase},XPath=Item}" FontSize="12" Background="LightGreen" ItemsPanel="{Binding RelativeSource={RelativeSource Self}, Path=Background}">
<ListBox.Resources>
<Style x:Key="ListBoxWrapStyle" TargetType="ListBox">
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<WrapPanel Width="{Binding FrameworkElement.ActualWidth),RelativeSource={RelativeSource AncestorType=ScrollContentPresenter}}" ItemWidth="{Binding (ListView.View).ItemWidth, RelativeSource={RelativeSource AncestorType=ListView}}" ItemHeight="{Binding (ListView.View).ItemHeight, RelativeSource={RelativeSource AncestorType=ListView}}" />
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ListBoxHorizontalStackStyle" TargetType="ListBox">
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<StackPanel Width="{Binding (FrameworkElement.ActualWidth),RelativeSource={RelativeSource AncestorType=ScrollContentPresenter}}" Orientation="Horizontal" />
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ListBoxVerticalStackStyle" TargetType="ListBox">
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<StackPanel Width="{Binding (FrameworkElement.ActualWidth),RelativeSource={RelativeSource AncestorType=ScrollContentPresenter}}" Orientation="Vertical" />
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
</Style>
</ListBox.Resources>
<ListBox.Style>
<Style TargetType="ListBox">
<Style.Triggers>
<!-- Your Trigger.. -->
<Trigger Property="Background" Value="Green">
<Setter Property="ItemsPanel" Value="{StaticResource ListBoxVerticalStackStyle}"/>
</Trigger>
<Trigger Property="Background" Value="LightBlue">
<Setter Property="ItemsPanel" Value="{StaticResource ListBoxHorizontalStackStyle}"/>
</Trigger>
<Trigger Property="Background" Value="LightGreen">
<Setter Property="ItemsPanel" Value="{StaticResource ListBoxWrapStyle}"/>
</Trigger>
</Style.Triggers>
</Style>
</ListBox.Style>
<ListBox.ItemTemplate>
<DataTemplate>
<Viewbox Stretch="Fill" HorizontalAlignment="Stretch" >
<Border BorderThickness="1" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" DataContext="{Binding}" BorderBrush="IndianRed" Margin="0" Height="Auto">
<DockPanel>
<Image
DockPanel.Dock="Top"
Width="150" Margin="5"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
Height="Auto" x:Name="Myimage"
RenderOptions.BitmapScalingMode="HighQuality" Source="{Binding XPath=@Image}">
</Image>
<Grid>
<TextBlock Text="{Binding XPath=@SNo}" HorizontalAlignment="Center" FontWeight="Normal" FontSize="13" />
</Grid>
</DockPanel>
</Border>
</Viewbox>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</DockPanel>
</Window>

Mientras ejecuto este código, estoy obteniendo ListBoxVerticalStackStyle ''solamente.

Answer 1

Como dice el error, está tratando de establecer un Style cuando espera una ItemsPanelTemplate como Setter.Value . Defina sus recursos como ItemPanelTemplate ''s de ListBox Style y debe ordenarlos

Pruebe algo como:

<ListBox Name="lv"
Background="LightBlue"
FontSize="12"
ItemsSource="{Binding Source={StaticResource myXmlDataBase},
XPath=Item}">
<ListBox.Resources>
<ItemsPanelTemplate x:Key="ListBoxWrapTemplate">
<WrapPanel Width="{Binding (FrameworkElement.ActualWidth),
RelativeSource={RelativeSource AncestorType=ScrollContentPresenter}}"
ItemHeight="{Binding (ListView.View).ItemHeight,
RelativeSource={RelativeSource AncestorType=ListView}}"
ItemWidth="{Binding (ListView.View).ItemWidth,
RelativeSource={RelativeSource AncestorType=ListView}}" />
</ItemsPanelTemplate>
<ItemsPanelTemplate x:Key="ListBoxHorizontalStackTemplate">
<StackPanel Width="{Binding (FrameworkElement.ActualWidth),
RelativeSource={RelativeSource AncestorType=ScrollContentPresenter}}"
Orientation="Horizontal" />
</ItemsPanelTemplate>
<ItemsPanelTemplate x:Key="ListBoxVerticalStackTemplate">
<StackPanel Width="{Binding (FrameworkElement.ActualWidth),
RelativeSource={RelativeSource AncestorType=ScrollContentPresenter}}"
Orientation="Vertical" />
</ItemsPanelTemplate>
</ListBox.Resources>
<ListBox.Style>
<Style TargetType="ListBox">
<Style.Triggers>
<!-- Your Trigger.. -->
<Trigger Property="Background"
Value="Green">
<Setter Property="ItemsPanel"
Value="{DynamicResource ListBoxVerticalStackTemplate}" />
</Trigger>
<Trigger Property="Background"
Value="LightBlue">
<Setter Property="ItemsPanel"
Value="{DynamicResource ListBoxHorizontalStackTemplate}" />
</Trigger>
<Trigger Property="Background"
Value="LightGreen">
<Setter Property="ItemsPanel"
Value="{DynamicResource ListBoxWrapTemplate}" />
</Trigger>
</Style.Triggers>
</Style>
</ListBox.Style>
...

Answer 2

Me preguntaba por qué la respuesta de Viv no funcionó en mi caso :-( Esto es lo que hice mal:

¡No defina los ItemsPanelTemplate appart de <Style.Triggers> ! Si coloca uno en <Listbox.ItemPanel></Listbox.ItemPanel> los desencadenantes de estilo no tendrán ningún efecto.

Arnaud.

pd: no hay suficiente reputación para comentar solo ...