I am attempting to create a generic ListBox control to customize edit in place as well as other features.
In the example below, I want to bind the "Text" property of the ListBox "selected item" to the data value of the DisplayMemberPath in the viewed structure. Such XAML binding expression would replace the question marks in the code (Text="{Binding ????????????????").
Using a ContentPresenter instead of binding the text works for display purposes, but I have not been able to bind to the Text component used on the presenter. An alternative to finding the binding expression is to be able to get the Text content from the ContentPresenter.
I can think of a number of ways to accomplish this through code behind, but I am looking for a XAML solution if such thing exists.
I appreciate any ideas. I am almost sure there is a trivial answer to this, but after spending a couple days on it, I admit a nudge in the right direction would greatly help me.
<Window x:Class="WpfApplication1.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="NobelLaureatesInPhysics"
XPath="/NobelLaureatesInPhysics">
<x:XData>
<NobelLaureatesInPhysics xmlns="">
<NobelLaureate>
<ID>1</ID>
<Name>Wilhelm Röntgen</Name>
<AwardDate>12/10/1901</AwardDate>
</NobelLaureate>
<NobelLaureate>
<ID>2</ID>
<Name>Hendrik Lorentz</Name>
<AwardDate>12/10/1902</AwardDate>
</NobelLaureate>
<NobelLaureate>
<ID>3</ID>
<Name>Pieter Zeeman</Name>
<AwardDate>12/10/1902</AwardDate>
</NobelLaureate>
</NobelLaureatesInPhysics>
</x:XData>
</XmlDataProvider>
<ControlTemplate x:Key="ItemTemplate"
TargetType="ListBoxItem">
<TextBlock Foreground="Black">
<ContentPresenter />
</TextBlock>
</ControlTemplate>
<ControlTemplate x:Key="SelectedItemTemplate"
TargetType="ListBoxItem">
<TextBox Background="Black"
Foreground="White"
Text="{Binding ????????????????"/>
</ControlTemplate>
<Style TargetType="{x:Type ListBoxItem}"
x:Key="ContainerStyle">
<Setter Property="Template"
Value="{StaticResource ItemTemplate}" />
<Style.Triggers>
<Trigger Property="IsSelected"
Value="True">
<Setter Property="Template"
Value="{StaticResource SelectedItemTemplate}" />
</Trigger>
</Style.Triggers>
</Style>
<Style x:Key="TestListBoxStyle"
TargetType="{x:Type ListBox}">
<Setter Property="ItemContainerStyle"
Value="{DynamicResource ContainerStyle}" />
</Style>
</Window.Resources>
<Grid>
<ListBox Style="{DynamicResource TestListBoxStyle}"
ItemsSource="{Binding Source={StaticResource NobelLaureatesInPhysics}, XPath=NobelLaureate}"
DisplayMemberPath="Name"/>
</Grid>
{Binding Path=DisplayMemberPath, RelativeSource={RelativeSource Mode=FindAncestor, Type={x:Type ListBox}}
That should work
Related
I'm trying to display on a DataGrid a ObservableCollection. For each item in the ObservableCollection, I have a ComboBox that displays the currently selected item (MyColor in my example) and lets the user choose a different color from the combobox. This was working reasonably well when my Enum MyColor was in the same namespace as the MainWindow. However, to make the example closer to the problem I'm actually trying to solve I put the MyColor enum in a different project and namespace. I've included all code. In the XAML for the mainwindow, I have a ObjectDataProvider and the line
<x:Type TypeName="enu:MyColor" />
The word x:Type is underlined and has the message: The name MyColor does not exist in the namespace "clr-namespace:Library.EnumDefinitions;assembly=Library.EnumDefinitions"
I've double and triple checked spelling, but don't see the problem. MyColor is defined in the namespace Library.EnumDefinitions. I'm wondering if the fact that the enum is in a separate namespace and project is causing me grief. The idea of using ObjectDataProvider can by found here for example:
https://brianlagunas.com/a-better-way-to-data-bind-enums-in-wpf/
The suggestion that there might be something special going on if your enum is in a different project/namespace is given here:
The name does not exist in the namespace in WPF application
I do have a reference to the different project in my Main project.
Any idea what is going on? If I can provide other information, please let me know.
Thanks,
Dave
MainWindow XAML
<Window x:Class="TrickyBindingProblems.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:enu="clr-namespace:Library.EnumDefinitions;assembly=Library.EnumDefinitions"
xmlns:sys="clr-namespace:System;assembly=mscorlib"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Window.Resources>
<ObjectDataProvider x:Key="EnumDataProvider" MethodName="GetValues"
ObjectType="{x:Type sys:Enum}">
<ObjectDataProvider.MethodParameters>
<x:Type TypeName="enu:MyColor" />
</ObjectDataProvider.MethodParameters>
</ObjectDataProvider>
</Window.Resources>
<Grid>
<DataGrid Grid.Column="1"
Margin="0"
HorizontalAlignment="Left"
AutoGenerateColumns="False"
Background="Transparent"
DataContext="{Binding}"
HeadersVisibility="Column"
ItemsSource="{Binding Cars}"
SelectedItem="{Binding SelectedItemProperty, Mode=TwoWay}"
RowBackground="Transparent"
RowHeight="30">
<DataGrid.CellStyle>
<Style TargetType="{x:Type DataGridCell}">
<Setter Property="Foreground" Value="Black" />
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="Background" Value="{x:Null}" />
<Setter Property="BorderBrush" Value="{x:Null}" />
</Trigger>
</Style.Triggers>
</Style>
</DataGrid.CellStyle>
<DataGrid.ColumnHeaderStyle>
<Style TargetType="{x:Type DataGridColumnHeader}">
<Setter Property="FontWeight" Value="Bold" />
</Style>
</DataGrid.ColumnHeaderStyle>
<DataGrid.Columns>
<DataGridTemplateColumn Width="*" Header="Make">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock VerticalAlignment="Center"
Padding="5"
Text="{Binding Make}" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Width="*" Header="Color (as ComboBox)">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox ItemsSource="{Binding Source={StaticResource EnumDataProvider}}" SelectedItem="{Binding Color, Mode=TwoWay}">
<ComboBox.Resources>
<Style TargetType="{x:Type TextBlock}">
<Setter Property="Foreground" Value="Black" />
</Style>
</ComboBox.Resources>
</ComboBox>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
</Grid>
namespace Library.EnumDefinitions
{
public enum MyColor
{
Red,
Blue,
Green
}
}
UPDATE!!!
I believe I fixed my immediate problem. I changed the line:
xmlns:enu="clr-namespace:Library.EnumDefinitions;assembly=Library.EnumDefinitions"
to:
xmlns:enu="clr-namespace:Library.EnumDefinitions"
Can someone tell me when you are suppose to use the "assembly" part and when you are not?
I am trying to create a custom control for a text block that when moused over, a border will appear. I am pretty new to WPF and have only made some very simple custom controls. I need to implement this in a XAML UserControl.
Any suggestions would be greatly appreciated. Thanks again, StackOverflow.
EDIT: I am going to have to bind a persistence property to several different controls, so I really need to do this in a custom control. This is what I have, and it isn't working:
xmlns:customControls="clr-namespace:****.CustomControls"
....
<customControls:MouseOverBorder>
<TextBlock Style="{StaticResource ResourceKey=HomePageButtonText}"
Height="100"
Width="100"
Margin="5"
Text="View Reports" />
</customControls:MouseOverBorder>
And the UserControl:
<UserControl
x:Class="****.MouseOverBorder"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d">
<UserControl.Resources>
<ResourceDictionary>
<Style x:Key="MouseOverBorder" TargetType="{x:Type Border}">
<Setter Property="BorderThickness" Value="1" />
<Setter Property="CornerRadius" Value="3" />
<Style.Triggers>
<Trigger Property="Border.IsMouseOver" Value="true">
<Setter Property="BorderBrush" Value="White" />
</Trigger>
</Style.Triggers>
</Style>
</ResourceDictionary>
</UserControl.Resources>
<Border Style="{DynamicResource MouseOverBorder}" BorderThickness="1" CornerRadius="3" SnapsToDevicePixels="True"/>
No need to make a UserControl. I've managed to accomplish this with the following markup:
<Border Style="{DynamicResource BorderStyle1}" BorderThickness="1" CornerRadius="3" >
<TextBlock Text="TextBlock" />
</Border>
Here's the style:
<Style x:Key="BorderStyle1" TargetType="{x:Type Border}">
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="CornerRadius" Value="3"/>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="BorderBrush" Value="#FF123BBA"/>
</Trigger>
</Style.Triggers>
</Style>
EDIT:
Still don't get it why do you need a UserControl (please don't call it custom control - these are different things), but let's consider your example.
When you write the following
<customControls:MouseOverBorder>
<TextBlock Style="{StaticResource ResourceKey=HomePageButtonText}"
Height="100"
Width="100"
Margin="5"
Text="View Reports" />
</customControls:MouseOverBorder>
you are actually setting MouseOverBorder.Content property. Originally it's Content is defined in MouseOverBorder.xaml file. So you are replacing all your UserControl structure with TextBlock. But still I got your idea and have solution for it.
First, add custom DependencyProperty and CLR wrapper for it to MouseOverBorder class:
public static readonly DependencyProperty MyContentTemplateProperty =
DependencyProperty.Register("MyContentTemplate", typeof(DataTemplate), typeof(MouseOverBorder), null);
[Browsable(true)]
[Category("Other")]
public DataTemplate MyContentTemplate
{
get { return (DataTemplate)GetValue(MyContentTemplateProperty); }
set { SetValue(MyContentTemplateProperty, value); }
}
Second, make something inside MouseOverBorder use this property, e.g.
<ContentPresenter ContentTemplate="{Binding MyContentTemplate, ElementName=userControl}"/>
<!-- userControl is the Name of MouseOverBorder, defined in xaml -->
At last, you can use your UserControl as following:
<customControls:MouseOverBorder>
<customControls:MouseOverBorder.MyContentTemplate>
<DataTemplate>
<TextBlock Style="{StaticResource ResourceKey=HomePageButtonText}"
Height="100"
Width="100"
Margin="5"
Text="View Reports" />
</DataTemplate>
</customControls:MouseOverBorder.MyContentTemplate>
</customControls:MouseOverBorder>
I used this MSDN tutorial to create an eye candy look for all the Button controls of my window, and that worked fine.
To make it even more reusable, I tried to put all in a UserControl: I created a ImageButton UC, then I encapsulated all that <Style> from <Window.Resources> to <UserControl.Resources>.
Then I changed my Button instances in XAML, from:
<Button Tag="Face.jpg" Content="Foo" />
To:
<uc:ImageButton Tag="Face.jpg" Content="Foo" />
And the style stopped being applied.
Here's the UC code:
<UserControl x:Class="GDTI.UI.Main.View.UserControls.ImageButton"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<UserControl.Resources>
<Style TargetType="Button">
<Setter Property="MaxWidth" Value="250" />
<Setter Property="Margin" Value="5" />
<Setter Property="FontWeight" Value="Bold" />
<Setter Property="Foreground" Value="White" />
<Setter Property="Background" >
<Setter.Value>
<SolidColorBrush Color="Orange" Opacity="0.4" />
</Setter.Value>
</Setter>
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate >
<StackPanel>
<Image Source="{Binding Tag,
RelativeSource={RelativeSource
FindAncestor,
AncestorType='Button'}}" />
<TextBlock Margin="10"
HorizontalAlignment="Center"
Text="{Binding Content,
RelativeSource={RelativeSource
FindAncestor,
AncestorType='Button'}}" />
</StackPanel>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
</UserControl.Resources>
<Button/>
What am I missing?
Thank you!
The bindings in the button-style target properties on the button, which no longer has the properties set. You need to forward those to the UserControl if you want to retain the style's integrity:
<!-- Inside UserControl declaration -->
<Button Content="{Binding Caption, RelativeSource={RelativeSource AncestorType=UserControl}}"
Tag="{Binding ImageSource, RelativeSource={RelativeSource AncestorType=UserControl}}"/>
Where Caption and ImageSource should be new dependency properties defined on the UserControl (in code-behind).
Note that you can never bind to Content in a UserControl (hence the Caption property), here the Button itself is the Content of the UserControl.
Alternatively you could directly change the targeting in the style by changing the AncestorType to UserControl which bypasses the Button. Binding beyond the templated control is not exactly good practice but your are still inside the UserControl so it may be forgivable.
Either way this is a bit hacky and it might be better to inherit from Button instead.
I'm try to set the Foreground colour on a Hyperlink using a Style object in an ancestor's Resources, but it's not having any effect. I even used the BasedOn tip from Changing Hyperlink foreground without losing hover color, but it's not made any difference - I still get a blue hyperlink that is red on hover.
Here's the XAML for my controls, including an ItemsControl whose items are shown using a hyperlink:
<StackPanel Background="Red" TextElement.Foreground="White">
<StackPanel.Resources>
<Style TargetType="Hyperlink" BasedOn="{StaticResource {x:Type Hyperlink}}">
<Setter Property="Foreground" Value="Yellow"/>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Foreground" Value="White"/>
</Trigger>
</Style.Triggers>
</Style>
</StackPanel.Resources>
<TextBlock>Data import errors</TextBlock>
<ItemsControl ItemsSource="{Binding Errors}"/>
</StackPanel>
And the items in the ItemsControl are picking up the following DataTemplate:
<DataTemplate DataType="{x:Type Importer:ConversionDetailsMessage}">
<TextBlock>
<Run Text="{Binding Message, Mode=OneTime}"/>
<Hyperlink Command="Common:ImportDataCommands.ExplainConversionMessage" CommandParameter="{Binding}">
<Run Text="{Binding HelpLink.Item2, Mode=OneTime}"/>
</Hyperlink>
</TextBlock>
</DataTemplate>
It's worth noting, too, that I don't want to just set the different colours directly on the Hyperlink in the DataTemplate. This is because the template will be used by a number of different ItemsControl objects, most of which will be on a white background and so can use the standard hyperlink colours. (Note that the one in the XAML above, however, has a red background.)
In short, I don't want the DataTemplate to have to know anything about the control in which it's being used. The styles for the template's controls should just filter down to it.
So... can anyone tell me why the style's not filtering down and what I can do to fix it?
Thanks.
Update:
Since I couldn't get Pavlo's answer to work in my production app, I've since tried it in a separate test app. The app is a WinForms app, with the main form containing nothing but an ElementHost, which itself contains a simple WPF usercontrol. Here's its XAML:
<UserControl x:Class="DataTemplateStyling.StylingView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:DataTemplateStyling="clr-namespace:DataTemplateStyling"
x:Name="root" Loaded="StylingViewLoaded">
<UserControl.Resources>
<Style x:Key="MyDefaultHyperlinkStyle" BasedOn="{StaticResource {x:Type Hyperlink}}"/>
<DataTemplate DataType="{x:Type DataTemplateStyling:ImportMessage}">
<DataTemplate.Resources>
<Style TargetType="{x:Type Hyperlink}"
BasedOn="{StaticResource MyDefaultHyperlinkStyle}"/>
</DataTemplate.Resources>
<TextBlock>
<Run Text="{Binding Message, Mode=OneTime}"/>
<Hyperlink NavigateUri="{Binding HelpLink.Item1}">
<Run Text="{Binding HelpLink.Item2, Mode=OneTime}"/>
</Hyperlink>
</TextBlock>
</DataTemplate>
</UserControl.Resources>
<Grid DataContext="{Binding ElementName=root}">
<StackPanel Background="Red" TextElement.Foreground="White">
<StackPanel.Resources>
<Style x:Key="MyDefaultHyperlinkStyle" TargetType="Hyperlink" BasedOn="{StaticResource {x:Type Hyperlink}}">
<Setter Property="Foreground" Value="Yellow"/>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Foreground" Value="White"/>
</Trigger>
</Style.Triggers>
</Style>
</StackPanel.Resources>
<TextBlock>Data import errors</TextBlock>
<ItemsControl ItemsSource="{Binding Messages}"/>
</StackPanel>
</Grid>
</UserControl>
As it stands above, this generates an InvalidOperationException, stating "Can only base on a Style with target type that is base type 'IFrameworkInputElement'."
That can be fixed by putting TargetType="Hyperlink" on the Style definition immediately inside the UserControl.Resources element. However, while the messages are being shown, the link part of them still has the default blue hyperlink styling:
In short, it's not working, so I'd welcome any other suggestions/corrections. :(
Update 2:
Thanks to an alternative solution from Pavlo, it now is working. :)
After some googling I ran into this post: http://www.11011.net/archives/000692.html.
As it described there, it turns out that elements that are not derived from Control (like TextBlock and Hyperlink) do not look for implicit styles outside the DataTemplate boundary.
Again, as the article says, the possible workaround is to specify the style key explicitly. In your case it might be something like this:
<StackPanel Background="Red" TextElement.Foreground="White">
<StackPanel.Resources>
<Style x:Key="MyDefaultHyperlinkStyle" TargetType="Hyperlink" BasedOn="{StaticResource {x:Type Hyperlink}}">
<Setter Property="Foreground" Value="Yellow"/>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Foreground" Value="White"/>
</Trigger>
</Style.Triggers>
</Style>
</StackPanel.Resources>
<TextBlock>Data import errors</TextBlock>
<ItemsControl ItemsSource="{Binding Errors}"/>
</StackPanel>
Then, you can add an implicit style for Hyperlink that just references our named style in the DataTemplate resources:
<DataTemplate DataType="{x:Type Importer:ConversionDetailsMessage}">
<DataTemplate.Resources>
<Style TargetType="{x:Type Hyperlink}"
BasedOn="{StaticResource MyDefaultHyperlinkStyle}"/>
</DataTemplate.Resources>
<TextBlock>
<Run Text="{Binding Message, Mode=OneTime}"/>
<Hyperlink Command="Common:ImportDataCommands.ExplainConversionMessage" CommandParameter="{Binding}">
<Run Text="{Binding HelpLink.Item2, Mode=OneTime}"/>
</Hyperlink>
</TextBlock>
</DataTemplate>
And because the data template can be used in different places, there is a possibility that parent container doesn't define a style with key "MyDefaultHyperlinkStyle". In this case an exception will be thrown saying that resource "MyDefaultHyperlinkStyle" cannot be found. To address this, you can define a style with such key that will only inherit default style somewhere in App.xaml:
<Style x:Key="MyDefaultHyperlinkStyle"
BasedOn="{StaticResource {x:Type Hyperlink}}/>
Update:
The code you included in your update will not work because of the nature of static resources, which means that the following resource reference in date template...
BasedOn="{StaticResource MyDefaultHyperlinkStyle}"
... will always point to the following resource (which is the default style):
<Style x:Key="MyDefaultHyperlinkStyle" BasedOn="{StaticResource {x:Type Hyperlink}}"/>
Static resource references are resolved at compile time, therefore the closest resource in the tree is used.
You might be tempted to use DynamicResource, but unfortunately it is not supported with the BasedOn property.
BUT, Foreground property supports dynamic resources, so we can use the same trick with brushes we use inside our style. Here is your test user control modified to use dynamic brushes:
<UserControl x:Class="DataTemplateStyling.StylingView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:DataTemplateStyling="clr-namespace:DataTemplateStyling"
x:Name="root"
Loaded="StylingViewLoaded">
<UserControl.Resources>
<SolidColorBrush x:Key="HyperlinkForeground"
Color="Blue" />
<SolidColorBrush x:Key="HyperlinkHoverForeground"
Color="Gray" />
<Style x:Key="MyDefaultHyperlinkStyle"
TargetType="Hyperlink"
BasedOn="{StaticResource {x:Type Hyperlink}}">
<Setter Property="Foreground"
Value="{DynamicResource HyperlinkForeground}" />
<Style.Triggers>
<Trigger Property="IsMouseOver"
Value="True">
<Setter Property="Foreground"
Value="{DynamicResource HyperlinkHoverForeground}" />
</Trigger>
</Style.Triggers>
</Style>
<DataTemplate DataType="{x:Type DataTemplateStyling:ImportMessage}">
<DataTemplate.Resources>
<Style TargetType="{x:Type Hyperlink}"
BasedOn="{StaticResource MyDefaultHyperlinkStyle}" />
</DataTemplate.Resources>
<TextBlock>
<Run Text="{Binding Message, Mode=OneTime}" />
<Hyperlink NavigateUri="{Binding HelpLink.Item1}">
<Run Text="{Binding HelpLink.Item2, Mode=OneTime}" />
</Hyperlink>
</TextBlock>
</DataTemplate>
</UserControl.Resources>
<Grid DataContext="{Binding ElementName=root}">
<StackPanel Background="Red"
TextElement.Foreground="White">
<StackPanel.Resources>
<SolidColorBrush x:Key="HyperlinkForeground"
Color="Yellow" />
<SolidColorBrush x:Key="HyperlinkHoverForeground"
Color="White" />
</StackPanel.Resources>
<TextBlock>Data import errors</TextBlock>
<ItemsControl ItemsSource="{Binding Messages}" />
</StackPanel>
</Grid>
</UserControl>
It works as expected, i.e. all links inside StackPanel will be Yellow/White, while outside they will be blue.
Hope this helps.
I have a ListBox control in WPF which contains items of variable height (predominantly a large text block, so it's also affected by word wrapping). Since scrolling behaves badly when the height of an individual item gets too high (especially when close to the height of the ListBox itself), I want to constrain the max height of the individual items.
I've done that readily enough, by using a Style to set the MaxHeight of the ListBoxItem container.
My problem is that I would like to detect that an individual item has hit that constraint, and then style it differently.
This was my first attempt:
<Style x:Key="LogContainerStyle" TargetType="{x:Type ListBoxItem}">
<Setter Property="MaxHeight" Value="64" />
<EventSetter Event="MouseDoubleClick" Handler="LogEntry_MouseDoubleClick" />
</Style>
<DataTemplate x:Key="LogTemplate">
<Grid>
<TextBlock Text="{Binding Message}" />
<TextBlock x:Name="More" Text="(more)"
HorizontalAlignment="Right" VerticalAlignment="Bottom"
Foreground="DarkGray" Visibility="Collapsed" />
</Grid>
<DataTemplate.Triggers>
<Trigger ... height capped at MaxHeight? ...>
<Setter TargetName="More" Property="Visibility" Value="Visible" />
</Trigger>
</DataTemplate.Triggers>
</DataTemplate>
But I'm not sure how to write the trigger. Alternatives welcome.
Try the code below. I set the ListBoxItem.MaxHeight to 99. I then added a trigger in the DataTemplate that checks the ActualHeight of the root element in the template (i.e. "bd" below) and if it's 99, I change the BorderBrush. Hope this helps.
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfApplication1"
xmlns:sys="clr-namespace:System;assembly=mscorlib"
ShowActivated="False"
Title="MainWindow" Height="350" Width="525">
<ListBox x:Name="lb">
<ListBox.ItemsSource>
<x:Array Type="{x:Type sys:Double}">
<sys:Double>250</sys:Double>
<sys:Double>100</sys:Double>
<sys:Double>50</sys:Double>
<sys:Double>25</sys:Double>
<sys:Double>99</sys:Double>
<sys:Double>120</sys:Double>
</x:Array>
</ListBox.ItemsSource>
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="MaxHeight" Value="99"/>
</Style>
</ListBox.ItemContainerStyle>
<ListBox.ItemTemplate>
<DataTemplate>
<Border x:Name="bd" BorderBrush="Black" BorderThickness="1">
<TextBlock Text="{Binding}" Height="{Binding}" Background="LightGray"/>
</Border>
<DataTemplate.Triggers>
<Trigger SourceName="bd" Property="ActualHeight" Value="99">
<Setter TargetName="bd" Property="BorderBrush" Value="Red"/>
</Trigger>
</DataTemplate.Triggers>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Window>