Dependency Injection

• Feb 26, 2026
• 3 minutes to read

Bind a View to a View Model

Configure the application dependency injection container and assign it to the IocServiceProvider.Default service at startup. The IocExtension can resolve MainViewModel from XAML during initialization:

App.xaml.cs

using DevExpress.Mvvm;
using Microsoft.Extensions.DependencyInjection;
using MvvmApp.ViewModels;

namespace MvvmApp {
    public partial class App : Application {
        // ...
        protected override void OnStartup(StartupEventArgs e) {
            IServiceProvider services = new ServiceCollection()
                .AddTransient<MainViewModel>()
                .BuildServiceProvider();
            // Configure the global provider before WPF starts loading StartupUri/XAML
            // The {dxmvvm:Ioc ...} config can resolve types in XAML during initialization
            IocServiceProvider.Default.ConfigureServices(services);
            base.OnStartup(e);

            var mainWindow = new MainWindow();
            MainWindow = mainWindow;
            mainWindow.Show();
        }
    }
}

Declare a MainViewModel class with a read-only Message property that contains text for UI binding:

MainViewModel.cs

namespace MvvmApp.ViewModels {
    public sealed class MainViewModel {
        public string Message { get; } = "DI works through the IocExtension";
    }
}

Use the IocExtension to resolve a MainViewModel from the configured dependency injection container. The window sets the resolved MainViewModel instance as DataContext, so the TextBlock can bind to the Message property:

MainWindow.xaml

<dx:ThemedWindow
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
    xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm"
    xmlns:vm="clr-namespace:MvvmApp.ViewModels"

    DataContext="{dxmvvm:Ioc Type={x:Type vm:MainViewModel}}">

    <Grid>
        <TextBlock Text="{Binding Message}"/>
    </Grid>
</dx:ThemedWindow>

Examples

Services

View Example: DevExpress MVVM Framework — Use DevExpress Services with a Dependency Injection

POCO

View Example: Register a POCO View Model in a Dependency Injection Container

Use POCO View Models with Dependency Injection

To use a POCO View Model in a dependency injection container, register the View Model type in the container:

C#

services.AddTransient(typeof(MainViewModel));

View Example: Register a POCO View Model in a Dependency Injection Container

Use Services with Dependency Injection

We recommend two different DevExpress service usage techniques with dependency injection depending on whether the required service is associated with a visual element.

Attached Service

1. If the service is attached to a specific visual element, add the following custom AttachServiceBehavior:

   C#

   public class AttachServiceBehavior : Behavior<DependencyObject> {
       public static readonly DependencyProperty AttachableServiceProperty =
           DependencyProperty.Register(
               nameof(AttachableService),
               typeof(ServiceBase),
               typeof(AttachServiceBehavior),
               new PropertyMetadata(null, OnAttachableServiceChanged));
   
       static void OnAttachableServiceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
           (e.OldValue as ServiceBase)?.Detach();
           ((AttachServiceBehavior)d).AttachService();
       }
   
       public ServiceBase AttachableService {
           get => (ServiceBase)GetValue(AttachableServiceProperty);
           set => SetValue(AttachableServiceProperty, value);
       }
   
       protected override void OnAttached() {
           base.OnAttached();
           AttachService();
       }
       protected override void OnDetaching() {
           base.OnDetaching();
           AttachableService?.Detach();
       }
   
       void AttachService() {
           if(AttachableService == null || AssociatedObject == null)
               return;
           if(AttachableService.IsAttached)
               AttachableService.Detach();
           AttachableService.Attach(AssociatedObject);
       }
   }
   

2. Add a public property that maps the service to the view model:

   C#

   public class MainViewModel {
       public INavigationService NavigationService { get; }
   
       public MainViewModel(INavigationService navigationService) =>
           NavigationService = navigationService;
   }
   

3. Use the AttachServiceBehavior property to attach the service to a visual element:

   XAML

   <dxwui:NavigationFrame>
       <dxmvvm:Interaction.Behaviors>
           <common:AttachServiceBehavior AttachableService="{Binding NavigationService}"/>
       </dxmvvm:Interaction.Behaviors>
   </dxwui:NavigationFrame>
   

   View Example: DevExpress MVVM Framework — Use DevExpress Services with a Dependency Injection

Unattached Service

1. If the service does not need to be attached to a specific visual element (such as Message Box Services), you can register the service in the dependency injection container:

   C#

   services.AddSingleton<IMessageBoxService, DXMessageBoxService>();
   

2. Specify the corresponding ViewModel property:

   C#

   public class MainViewModel {
       readonly IMessageBoxService messageBoxService;
       public MainViewModel(IMessageBoxService messageBoxService) {
           this.messageBoxService = messageBoxService;
       }
   }
   

Tip

If you configure the service to work with an individual View, dependency injection is not recommended. Use the technique described in the following section instead: Implement Services in Your Application.