ItemStyle Selector

The ListView component exposes conditional styling feature. It allows users to apply a different Style to each item depending on a specific condition.

Example

The following example will demonstrate how to apply the Conditional Styling in the ListView control. Let's add the RadlistView component and create a simple data.

1. Set up the ListView control:

    <telerikDataControls:RadListView x:Name="listView"
                                   ItemsSource="{Binding Source}">
     <telerikDataControls:RadListView.BindingContext>
         <local:ViewModel />
     </telerikDataControls:RadListView.BindingContext>
     <telerikDataControls:RadListView.ItemTemplate>
         <DataTemplate>
             <telerikListView:ListViewTemplateCell>
                 <telerikListView:ListViewTemplateCell.View>
                     <StackLayout>
                         <Label Margin="10" Text="{Binding Name}" />
                         <Label Margin="10"
                                FontSize="10"
                                Text="{Binding Age}" />
                     </StackLayout>
                 </telerikListView:ListViewTemplateCell.View>
             </telerikListView:ListViewTemplateCell>
         </DataTemplate>
     </telerikDataControls:RadListView.ItemTemplate>
   
     <telerikDataControls:RadListView.ItemStyleSelector>
         <local:ExampleListViewStyleSelector />
     </telerikDataControls:RadListView.ItemStyleSelector>
   </telerikDataControls:RadListView>
   

2. Create a simple data for the ListView component:

    public class Person
   {
     public Person(string name, int age)
     {
         this.Name = name;
         this.Age = age;
     }
   
     public string Name { get; set; }
   
     public int Age { get; set; }
   }
   
   public class ViewModel
   {
     public ViewModel()
     {
         this.Source = new List<Person> {
             new Person("Tom", 25),
             new Person("Anna",18),
             new Person("Peter",43),
             new Person("Teodor",29),
             new Person("Lorenzo",65),
             new Person("Andrea",79),
             new Person("Martin",5) };
     }
   
     public List<Person> Source { get; set; }
   }
   

3. You can set a different style for a specific item by using the ListViewStyleSelector class. We can use the OnSelectStyle method to change the styles of the items in the ListView control. A sample implementation of a custom class that derives from ListViewStyleSelector and overrides its OnSelectStyle method is shown below:

    public class ExampleListViewStyleSelector : ListViewStyleSelector
   {
     protected override void OnSelectStyle(object item, ListViewStyleContext styleContext)
     {
         var style = new ListViewItemStyle
         {
             BackgroundColor = Colors.Transparent
         };
   
         styleContext.ItemStyle = style;
         styleContext.SelectedItemStyle = new ListViewItemStyle
         {
             BackgroundColor = Colors.Gray,
             BorderColor = Colors.Red,
             BorderWidth = 2
         };
   
         var sourceItem = item as Person;
         if (sourceItem.Age < 18)
         {
             styleContext.ItemStyle.BackgroundColor = Colors.Blue;
         }
         else if (sourceItem.Age < 65)
         {
             styleContext.ItemStyle.BackgroundColor = Colors.Green;
         }
     }
   }
   

   The following image shows how the ListView control will look like when conditional styling is used.

The SDK Browser application contains an example that shows the StyleSelector feature in the ListView control.

See Also

• Selection
• Styling
• Reordering