Need multiple styles dependent on Listboxitem - wpf

i have a Listbox, which stores two different object types, based on the same baseclass. (e.g. BaseObject = baseclass and the children of it: CustomPath and CustomImage)
The Datasource:
ObservableCollection<BattlegroundBaseObject> _baseObjectCollection;
public ObservableCollection<BattlegroundBaseObject> BaseObjectCollection
{
get { return _baseObjectCollection?? (_baseObjectCollection= new ObservableCollection<BaseObject>()); }
}
The Listbox databinding: <ListBox ItemsSource="{Binding BaseObjectCollection}"
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem" x:Name="ListBoxPathLineStyle">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListBoxItem" x:Name="BattlegroundObjectControlTemplate">
<Path Stroke="{Binding ObjectColor}" StrokeThickness="{Binding StrokeThickness}" Data="{Binding PathGeometryData}" x:Name="PathLine" Opacity="{Binding Opacity}">
</Path>
<ControlTemplate.Triggers>
<Trigger Property="IsSelected" Value="true">
<Setter Property="Effect" TargetName="PathLine">
<Setter.Value>
<DropShadowEffect Color="CornflowerBlue" ShadowDepth="3" BlurRadius="10" />
</Setter.Value>
</Setter>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ListBox.ItemContainerStyle>
I want to add to the ControlTemplate where the Path is, also a Image and to differ it by type or a property. doesnt matter.
anyone any ideas?

You can add to ListBox resources DataTemplate for each type.
In my example classes Car and Motorbike derived from Vehicle class.
<ListBox x:Name="listBox">
<ListBox.Resources>
<DataTemplate DataType="{x:Type local:Car}">
<StackPanel Background="Red">
<TextBlock Text="{Binding Name}" />
</StackPanel>
</DataTemplate>
<DataTemplate DataType="{x:Type local:Motorbike}">
<StackPanel Background="Orange">
<TextBlock Text="{Binding Name}" />
</StackPanel>
</DataTemplate>
</ListBox.Resources>
</ListBox>
EDIT:
You can add style for ListBoxItem to resources:
<ListBox x:Name="listBox">
<ListBox.Resources>
<Style TargetType="ListBoxItem">
<Style.Triggers>
<Trigger Property="IsSelected" Value="true">
<Setter Property="Effect">
<Setter.Value>
<DropShadowEffect Color="CornflowerBlue" ShadowDepth="3" BlurRadius="10" />
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
<DataTemplate DataType="{x:Type local:Car}">
<StackPanel Background="Red">
<TextBlock Text="{Binding Name}" />
</StackPanel>
</DataTemplate>
<DataTemplate DataType="{x:Type local:Motorbike}">
<StackPanel Background="Orange">
<TextBlock Text="{Binding Name}" />
</StackPanel>
</DataTemplate>
</ListBox.Resources>
</ListBox>

You could define some DataTemplates for your different classes. They determine how the classes are displayed. I've been using them to display derived classes differently when working with a collection of the base class.
<DataTemplate DataType="{x:Type CustomPath}">
<TextBlock Text="This is a CustomPath"/>
</DataTemplate>
<DataTemplate DataType="{x:Type CustomImage}">
<TextBlock Text="This is a CustomImage"/>
</DataTemplate>

At the moment you are changing the style of the controls that WPF is using to render your bound data. A better way to do this is to provide WPF with a way of generating the correct controls. Ignore the ListBoxItem and use DataTemplates for your actual objects.
First you need to tell the Window or control how to find your types.
<Window or UserControl
...
xmlns:model="clr-namespace:yourNamespace"
>
Then you can provide WPF with a way to show your objects e.g.
<DataTemplate TargetType="{x:Type model:CustomPath}">
<Path Stroke="{Binding ObjectColor}" StrokeThickness="{Binding StrokeThickness}"
Data="{Binding PathGeometryData}" x:Name="PathLine" Opacity="{Binding Opacity}"/>
<!-- maybe use a binding from the Path.Effect back to the IsSelected and ValueConverters
to re-apply the selection effect-->
</DataTemplate>
<DataTemplate TargetType="{x:Type model:CustomImage}">
<Image Src="{Binding SomeProperty}" />
</DataTemplate>
Now all you need to do is to make these available to the ListBox in some way. Almost every element in WPF can have .Resources added to it, so you could choose to do these across the entire window
<Window ...>
<Window.Resources>
<DataTemplate .../>
<DataTemplate .../>
</Window.Resources>
...
<ListBox .../>
</Window>
or you can apply it more locally
<Window ...>
...
<ListBox>
<ListBox.Resources>
<DataTemplate .../>
<DataTemplate .../>
</ListBox.Resources>
</ListBox>
</Window>
And this way your listbox definition can become much neater too, e.g. if you are using Window.Resources
<ListBox ItemsSource="{Binding BaseObjectCollection}"/>

Related

Handling different item templates that share the same content

I have two custom ItemTemplates for the ListBox, one for the regular items, and one for the selected item. An example of how would I handle this is:
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="ContentTemplate" Value="{StaticResource Template1}" />
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="ContentTemplate" Value="{StaticResource Template2}" />
</Trigger>
</Style.Triggers>
</Style>
</ListBox.ItemContainerStyle>
Template1 and Template2 are very similar:
<DataTemplate x:Key="Template1">
<SameContent />
<DifferentContent1 />
</DataTemplate>
<DataTemplate x:Key="Template2">
<SameContent />
<DifferentContent2 />
</DataTemplate>
So, is it a proper way to duplicate the code for the SameContent (which is like a bunch of TextBlocks, Panels, etc) in both templates, or it is a better approach to have only one template, but switch the DifferentContent based on the IsSelected property, or...?
if second approach, how would it be properly done?
Obviously duplicating the code is not a very good solution. A better approach is to define another DataTemplate as your common content and then use ContentPresenter to present it:
<Window.Resources>
<DataTemplate x:Key="CommonTemplate">
<TextBlock Text="{Binding CommonProperty1}" />
<TextBlock Text="{Binding CommonProperty2}" />
</DataTemplate>
<DataTemplate x:Key="Template1" >
<StackPanel>
<ContentPresenter ContentTemplate="{StaticResource CommonTemplate}"/>
<TextBlock Text="{Binding Template1Property1}"/>
<TextBlock Text="{Binding Template1Property2}"/>
</StackPanel>
</DataTemplate>
<DataTemplate x:Key="Template2" >
<StackPanel>
<ContentPresenter ContentTemplate="{StaticResource CommonTemplate}"/>
<TextBlock Text="{Binding Template2Property1}"/>
<TextBlock Text="{Binding Template2Property2}"/>
</StackPanel>
</DataTemplate>
</Window.Resources>

WPF - Move ListView.GroupStyle to external XAML

After several hours I gave up.
I have the following ListView (in Grid) with GroupStyle defined inside of it.
I want to take it out somehow and put it in a Template or Style (I'm confused) and then add it to my main Style of the ListView (ListViewSimpleStyle).
This way it will be reusable in other places instead of copy-paste it every time.
How do I do it?
<ListView Name="LvDataBinding" Grid.Row="0"
Style="{StaticResource ListViewSimpleStyle}">
<!-- Define the grouping-->
<ListView.GroupStyle>
<GroupStyle>
<GroupStyle.HeaderTemplate>
<DataTemplate>
<TextBlock FontSize="12" Text="{Binding Name}"
Foreground="{StaticResource GrayForgroundBrush}"></TextBlock>
</DataTemplate>
</GroupStyle.HeaderTemplate>
</GroupStyle>
</ListView.GroupStyle>
</ListView>
Thanks
Groupstyle is style of Groupbox so we need to edit style of Groupbox and I have changed GroupBox HeaderTemplate as you want to change HeaderTemplate of GroupStyle.
Visit this:http://msdn.microsoft.com/en-us/library/ms754027(v=vs.90).aspx
and Add GroupBox With Its style in your own listview template style i.e ListViewSimpleStyle
<Style x:Key="ListViewSimpleStyle" TargetType="ListView">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListView">
<Grid Background="AliceBlue" >
<GroupBox>
<GroupBox.Style>
<Style TargetType="GroupBox">
<Setter Property="HeaderTemplate">
<Setter.Value>
<DataTemplate>
<TextBlock FontSize="12" Text="{Binding Name}" Foreground="{StaticResource GrayForgroundBrush}"/>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupBox.Style>
</GroupBox>
<ItemsPresenter></ItemsPresenter>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>

Binding a command defined in a datatemplate

I know there are few answers on this topic. But none of them was working in my case.
I have a ListView with a style and an ItemContainerStyle. In the ItemContainer Style, I define some triggers in order to use a different DataTemplate depending if the item in the list is selected or not. Then, finally in the Datatemplate I have a context menu with a command. The problem is how to bind the command to the viewmodel.
This is the ListView:
<ListView
x:Name="lstPersons"
Grid.Row="1"
Style="{StaticResource ListViewStyle}"
ItemContainerStyle="{StaticResource ItemContainerStyle}"
DataContext="{Binding}"
ItemsSource="{Binding Path=Persons}"
Tag="{Binding}"
SelectedItem="{Binding Path=SelectedPerson, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
</ListView>
and these are the styles, datatemplates and contextmenu (defined in a resource dictionary).
The commands in the context menu do not work....:
<ContextMenu x:Key="SelectedItemContextMenu">
<MenuItem
Header="Do Something"
Command="{Binding Path=DataContext.DoSomethingCmd, ElementName=LayoutRoot}">
</MenuItem>
<MenuItem
Header="Do Something"
Command="{Binding PlacementTarget.Tag.DoSomethingCmd, RelativeSource={RelativeSource AncestorType=ContextMenu}}">
</MenuItem>
</ContextMenu>
<DataTemplate
x:Key="ItemTemplate">
<Canvas
Margin="4"
Width="60"
Height="60"
Background="LightGray">
<TextBlock
Foreground="Black"
Margin="2 0 0 0"
Opacity="0.5"
FontFamily="Segoe UI"
Text="{Binding Path=FirstName}" />
</Canvas>
</DataTemplate>
<DataTemplate
x:Key="ItemSelectedTemplate">
<Grid>
<Border
BorderBrush="Black"
BorderThickness="1"
Margin="3"
ContextMenu="{DynamicResource SelectedItemContextMenu}">
<Canvas
Width="60"
Height="60"
Background="LightBlue">
<TextBlock
Foreground="Black"
Margin="2 0 0 0"
Opacity="0.5"
FontFamily="Segoe UI"
Text="{Binding Path=FirstName}" />
</Canvas>
</Border>
</Grid>
</DataTemplate>
<!--style of the listviewitem-->
<Style
TargetType="{x:Type ListViewItem}"
x:Key="ItemContainerStyle">
<Setter
Property="ContentTemplate"
Value="{StaticResource ItemTemplate}" />
<Style.Triggers>
<Trigger
Property="IsSelected"
Value="True">
<Setter
Property="ContentTemplate"
Value="{StaticResource ItemSelectedTemplate}" />
</Trigger>
</Style.Triggers>
</Style>
<!--style of the listview-->
<Style
TargetType="{x:Type ListBox}"
x:Key="ListViewStyle">
<Setter
Property="Template">
<Setter.Value>
<ControlTemplate
TargetType="{x:Type ListBox}">
<Grid>
<Border>
<ScrollViewer
Focusable="false">
<WrapPanel
IsItemsHost="True"
Orientation="Horizontal"
Width="{Binding (FrameworkElement.ActualWidth), RelativeSource={RelativeSource AncestorType=ScrollContentPresenter}}"/>
</ScrollViewer>
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Your ContextMenu is used inside a data template. I will be put in a different name scope of "LayoutRoot" and ElementName binding won't work. Also, the PlacementTarget of your context menu is the Border, and you've not setup any Tag on it. So the second command won't work either.
It looks like you are implement the commands on the ListBox level (or LayoutRoot?). It might be easier to put your context menu on the ListBox, and use ListBox.SelectedItem to find the current selection and apply your logic on it.
You can use RelativeSource:
<ContextMenu x:Key="SelectedItemContextMenu">
<MenuItem
Header="Do Something"
Command="{Binding Path=DataContext.DoSomethingCmd, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}">
</MenuItem>
</ContextMenu>
You should probably be using RoutedCommands instead of VM commands in this case. You would bind the RoutedCommand to the ContextMenu, and since you only need static object references for that, finding them shouldn't be a problem. Then you'd set up appropriate CommandBindings on the controls that should handle the commands (either ListView or ListViewItem, depending on whether you want the List-ViewModel or the Item-ViewModel to handle the command). These controls will know their ViewModels, so binding to them will not be a problem there. Through the process of Command Routing, which is built-in in WPF, the context menu will find the proper target for its command automatically.
For guidance on how to set up CommandBindings in a MVVM-friendly way, you might want to refer to http://wpfglue.wordpress.com/2012/05/07/commanding-binding-controls-to-methods/

HeaderTemplate with multiple items

I'm trying to write a HeaderTemplate for an extender. So far, I've noticed all the examples use the {Binding} keyword to get the data from the header. However, what happens if there are multiple controls within the Header? How do I specify that those controls should be inserted at a specific location?
<Window.Resources>
<Style x:Key="ExpanderStyle" TargetType="{x:Type Expander}">
<Setter Property="HeaderTemplate">
<Setter.Value>
<DataTemplate>
<!-- what do I put in here? -->
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Expander Style="{StaticResource ExpanderStyle}">
<Expander.Header>
<StackPanel Orientation="Horizontal">
<TextBlock>Some Text</TextBlock>
<TextBlock Text="{Binding SomeBinding}" />
<Button />
</StackPanel>
</Expander.Header>
<Image Source="https://www.google.com/logos/2012/steno12-hp.jpg" />
</Expander>
Should I be moving my binding into the HeaderTemplate in the style and just overwriting whatever the Header in the Expander is?
You can use ContentPresenter to insert whatever the usual content would be into your Template
For example:
<Style x:Key="ExpanderStyle" TargetType="{x:Type Expander}">
<Setter Property="HeaderTemplate">
<Setter.Value>
<DataTemplate>
<Border BorderBrush="Blue" BorderThickness="2">
<ContentPresenter />
</Border>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
Header's property Content could contain only one object.
If you merge these object in one panel:
<StackPanel>
<TextBlock>Some Text</TextBlock>
<TextBlock Text="{Binding SomeBinding}" />
<Button />
</StackPanel>
then in template you could use {binding}

Automatic Scrolling in a Silverlight List Box with Custom Template

I have ListBox with custom template, how do programmatically scroll it down to bottom?
Automatic Scrolling in a Silverlight List Box describes method of scrolling to bottom of ListBox. Unfortunately this method does not work with ListBox with custom style template.
Have anyone success to scroll ListBox with custom style?
Problem code:
<Grid.Resources>
<Style x:Key="HorizontalWrapListBox" TargetType="ListBox">
<Style.Setters>
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<toolkit:WrapPanel Orientation="Horizontal" />
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListBox">
<ScrollViewer>
<ItemsPresenter />
</ScrollViewer>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style.Setters>
</Style>
</Grid.Resources>
<ListBox x:Name="MyListBox" Margin="0,0,-12,0" ItemsSource="{Binding Items}"
Style="{StaticResource HorizontalWrapListBox}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Margin="0,0,0,17" Width="432" Height="78">
<TextBlock Text="{Binding LineOne}" TextWrapping="Wrap"
Style="{StaticResource PhoneTextExtraLargeStyle}"/>
<TextBlock Text="{Binding LineTwo}" TextWrapping="Wrap"
Margin="12,-6,12,0"
Style="{StaticResource PhoneTextSubtleStyle}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
You need to keep correct naming of your template parts and this could just start working. The ScrollViewer should be named x:Name="ScrollViewer". Check
ListBox Styles and Templates,
Customizing the Appearance of an Existing Control by Using a ControlTemplate,
TemplatePartAttribute

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