How to set style ListBox items in WPF? - wpf

Question

My XAML code is: <ListBox Name="Seq"><TextBlock Name="txt1" Text="Hello"/></ListBox>
Code-behind would be:Seq.Style = ...; or txt1.Style=...;
I want to make some items green, bold and italic. What should I do? Thanks.

Answer 1

You can add style in App.xaml as per your requirement, for example :
<Style TargetType="TextBlock" x:Key="mystyle">
<Setter Property="Foreground" Value="Green"></Setter>
<Setter Property="FontStyle" Value="Italic"></Setter>
<Setter Property="FontWeight" Value="Bold"></Setter>
</Style>
and then you can apply that style to text block of list box as below:
this.txt1.Style = (Style)Application.Current.FindResource("mystyle");

Answer 2

What you really should do is to bind the ItemsSource property of the ListBox to an IEnumerable<T> and then add properties to the type T that you can bind to in an ItemTemplate, e.g.:
<ListBox Name="Seq">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock x:Name="txt1" Text="{Binding TextProperty}" />
<DataTemplate.Triggers>
<DataTrigger Binding="{Binding SomeOtherProperty}" Value="SomeValue">
<Setter TargetName="txt1" Property="Foreground" Value="Green" />
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
As a quick fix you could define a TextBlock style in your XAML markup:
<ListBox Name="Seq">
<ListBox.Resources>
<Style x:Key="style" TargetType="TextBlock">
<Setter Property="Foreground" Value="Green" />
<Setter Property="FontWeight" Value="Bold" />
<Setter Property="FontStyle" Value="Italic" />
</Style>
</ListBox.Resources>
<TextBlock Name="txt1" Text="Hello"/>
</ListBox>
...and set the Style property of the TextBlock, either programmatically:
txt1.Style = Seq.Resources["style"] as Style;
...or directly in the XAML markup:
<TextBlock Name="txt1" Text="Hello" Style="{StaticResource style}"/>