# Services in Generated View Models | WPF Controls | DevExpress Documentation [Runtime-generated POCO View Models](/WPF/17352/mvvm-framework/viewmodels/runtime-generated-poco-viewmodels) and [View Models Generated at Compile Time](/WPF/402989/mvvm-framework/viewmodels/compile-time-generated-viewmodels) can work with Services. ## Services in POCO - XAML

<UserControl x:Class="ViewModelBaseSample.View" 
             xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm" 
             xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
             xmlns:ViewModels="clr-namespace:ViewModelBaseSample.ViewModels"
             DataContext="{dxmvvm:ViewModelSource ViewModel:ViewModel}"  ...> 
    <dxmvvm:Interaction.Behaviors>
        <dx:DXMessageBoxService/>
    </dxmvvm:Interaction.Behaviors>
    ...
</UserControl>

- C# - VB.NET

using DevExpress.Mvvm.POCO;
...
public class ViewModel {
    public IMessageBoxService MessageBoxService { get { return this.GetService<IMessageBoxService>(); } }
}

Imports DevExpress.Mvvm.POCO
...
Public Class ViewModel
    Public ReadOnly Property MessageBoxService() As IMessageBoxService
        Get
            Return Me.GetService(Of IMessageBoxService)()
        End Get
    End Property
End Class

To control the generation of service properties, use the **ServiceProperty** attribute or Fluent API. For instance, you can define several services of the same type and access a specific service by its name. - XAML

<UserControl x:Class="ViewModelBaseSample.View" 
             xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm" 
             xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
             xmlns:ViewModels="clr-namespace:ViewModelBaseSample.ViewModels"
             DataContext="{dxmvvm:ViewModelSource ViewModel:ViewModel}"  ...> 
    <dxmvvm:Interaction.Behaviors>
        <dx:DXMessageBoxService x:Name="service1"/>
        <dx:DXMessageBoxService x:Name="service2"/>
    </dxmvvm:Interaction.Behaviors>
    ...
</UserControl>

- C# - VB.NET

public class ViewModel {
        [ServiceProperty(Key = "service1")]
        public virtual IMessageBoxService MessageBoxService1 { get { return null; } }
        [ServiceProperty(Key = "service2")]
        public virtual IMessageBoxService MessageBoxService2 { get { return null; } }
    }

Public Class ViewModel
    <ServiceProperty(Key := "service1")> _
    Public Overridable ReadOnly Property MessageBoxService1 As IMessageBoxService
        Get
            Return Nothing
        End Get
    End Property
    <ServiceProperty(Key := "service2")> _
    Public Overridable ReadOnly Property MessageBoxService2 As IMessageBoxService
        Get
            Return Nothing
        End Get
    End Property
End Class

Alternatively, you can manually define properties to access services. To do so, define a non-virtual property and use one of **POCOViewModelExtensions**‘ **GetService** extension methods as shown in the code snippet below. - C# - VB.NET

using DevExpress.Mvvm.POCO;
...
public class ViewModel {
    public IMessageBoxService MessageBoxService1 { get { return this.GetService<IMessageBoxService>("service1"); } }
    public IMessageBoxService MessageBoxService2 { get { return this.GetService<IMessageBoxService>("service2"); } }
}

Imports DevExpress.Mvvm.POCO
...
Public Class ViewModel
    Public ReadOnly Property MessageBoxService1() As IMessageBoxService
        Get
            Return Me.GetService(Of IMessageBoxService)("service1")
        End Get
    End Property
    Public ReadOnly Property MessageBoxService2() As IMessageBoxService
        Get
            Return Me.GetService(Of IMessageBoxService)("service1")
        End Get
    End Property
End Class

View Models can be related to each other with the parent-child relationship. This is achieved with the **ISupportParentViewModel** interface that is automatically implemented when you create a POCO object with the **ViewModelSource** class. You can pass the main View Model to the child using the **ISupportParentViewModel.ParentViewModel** property. This allows the child View Model to access Services that are registered for the main View Model. Please review the following topic for more information about this mechanism: [ViewModel relationships (ISupportParentViewModel)](/WPF/17449/mvvm-framework/viewmodels/viewmodel-relationships-isupportparentviewmodel). Here is an example that demonstrates the use of services when POCO View Models are related to each other with the parent-child relationship: [DXMessageBoxService](/WPF/17415/mvvm-framework/services/predefined-set/message-box-services/dxmessageboxservice). ## Services in View Models Generated at Compile Time To use Services in [View Models Generated at Compile Time](/WPF/402989/mvvm-framework/viewmodels/compile-time-generated-viewmodels), set the **ImplementISupportServices** property of the **GenerateViewModel** attribute to **true**. - Base View Model

[GenerateViewModel(ImplementISupportServices = true)]
public partial class ServicesViewModel {
    IMessageBoxService MessageBoxService => ServiceContainer.GetService<IMessageBoxService>(ServiceSearchMode.PreferParents);
    [GenerateCommand]
    void ShowMessage() => MessageBoxService.ShowMessage("Message");
}

- Generated View Model

partial class ServicesViewModel : INotifyPropertyChanged, ISupportServices {
    public event PropertyChangedEventHandler? PropertyChanged;
    IServiceContainer? serviceContainer;
    protected IServiceContainer ServiceContainer { get => serviceContainer ??= new ServiceContainer(this); }
    IServiceContainer ISupportServices.ServiceContainer { get => ServiceContainer; }
    protected T? GetService<T>() where T : class => ServiceContainer.GetService<T>();
    protected T GetRequiredService<T>() where T : class => ServiceContainer.GetRequiredService<T>();

    protected void RaisePropertyChanged(PropertyChangedEventArgs e) => PropertyChanged?.Invoke(this, e);

    DelegateCommand? showMessageCommand;
    public DelegateCommand ShowMessageCommand => showMessageCommand ??= new DelegateCommand(ShowMessage, null, true);
}