ViewInjectionService

• Jun 07, 2019
• 6 minutes to read

The ViewInjectionService is an IViewInjectionService implementation that allows you to integrate any ViewModel (with its View) to controls.

Note

You are viewing ViewInjectionService documentation. If you’re starting a new project, we strongly recommend that you use Module Injection Framework (MIF).

Assume that you have several views with view models (CustomersView/CustomersViewModel, ProductsView/ ProductsViewModel and SalesView/SalesViewModel) that have to be shown in an items control.

To accomplish this task, place the items control (suppose, it’s a FlipView control) on the MainView and add the ViewInjectionService to the control’s dxmvvm:Interaction.Behaviors collection as usual.

XAML

<UserControl x:Class="DXSample.View.MainView"
    ...
    xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
    xmlns:dxwui="http://schemas.devexpress.com/winfx/2008/xaml/windowsui"
    xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm"
    xmlns:common="clr-namespace:DXSample.Common"
    xmlns:v="clr-namespace:DXSample.View">
    <Grid>
        <dx:LoadingDecorator Grid.Row="1" >
            <dxwui:FlipView>
                <dxmvvm:Interaction.Behaviors>
                    <dxmvvm:ViewInjectionService RegionName="{x:Static common:Regions.Main}"/>
                </dxmvvm:Interaction.Behaviors>
            </dxwui:FlipView>
        </dx:LoadingDecorator>
    </Grid>
</UserControl>

Inject views with view models using the ViewInjectionManager’s Inject method (To learn more about concepts of ViewInjectionService and ViewInjectionManager, refer to the View Injection Service Concept and View Injection Manager Concept topics respectively). For example, perform injections in the Startup event handler.

C#

public partial class App : Application {
    private void Application_Startup(object sender, StartupEventArgs e) {
        InitModules();
        ...
    }

    private void InitModules() {
        ViewInjectionManager.Default.Inject(
            Regions.Main,
            ModuleType.Customers,
            () => CustomersViewModel.Create(),
            typeof(CustomersView)
        );

        ViewInjectionManager.Default.Inject(
            Regions.Main,
            ModuleType.Sales,
            () => SalesViewModel.Create(),
            typeof(SalesView)
        );

        ViewInjectionManager.Default.Inject(
            Regions.Main,
            ModuleType.Products,
            () => ProductsViewModel.Create(),
            typeof(ProductsView)
        );

        ViewInjectionManager.Default.Navigate(Regions.Main, ModuleType.Customers);
    }
}

VB.NET

Partial Public Class App
    Inherits Application

    Private Sub Application_Startup(ByVal sender As Object, ByVal e As StartupEventArgs)
        InitModules()
        ...
    End Sub
    Private Sub InitModules()
        ViewInjectionManager.Default.Inject(
            Regions.Main, 
            ModuleType.Customers, 
            Function() CustomersViewModel.Create(), 
            GetType(CustomersView)
        )
        ViewInjectionManager.Default.Inject(
            Regions.Main, 
            ModuleType.Sales, 
            Function() SalesViewModel.Create(), 
            GetType(SalesView)
        )
        ViewInjectionManager.Default.Inject(
            Regions.Main, 
            ModuleType.Products, 
            Function() ProductsViewModel.Create(), 
            GetType(ProductsView)
        )
        ViewInjectionManager.Default.Navigate(Regions.Main, ModuleType.Customers)
    End Sub
End Class

The Regions class is a static class with static string properties.

C#

public static class Regions {
    public static string Main { get { return "MainRegion"; } }
    public static string Navigation { get { return "NavigationRegion"; } }  
}

VB.NET

Public NotInheritable Class Regions
    Public Shared ReadOnly Property Main() As String
        Get
            Return "MainRegion"
        End Get
    End Property
    Public Shared ReadOnly Property Navigation() As String
        Get
            Return "NavigationRegion"
        End Get
    End Property
End Class

ModuleType is an enumeration:

C#

public enum ModuleType { 
    Customers, 
    Sales, 
    Products 
}

VB.NET

Public Enum ModuleType
    Customers
    Sales
    Products
End Enum

The FlipView is populated. Add a navigation view to our MainView.

XAML

<UserControl x:Class="DXSample.View.MainView"
    …
    xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
    xmlns:dxwui="http://schemas.devexpress.com/winfx/2008/xaml/windowsui"
    xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm"
    xmlns:common="clr-namespace:DXSample.Common"
    xmlns:v="clr-namespace:DXSample.View">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <dxui:TileBar Padding="10" >
            <dxmvvm:Interaction.Behaviors>
                <dxmvvm:ViewInjectionService RegionName="{x:Static common:Regions.Navigation}" />
            </dxmvvm:Interaction.Behaviors>
        </dxui:TileBar>
        <dx:LoadingDecorator Grid.Row="1">
            <dxwui:FlipView>
                <dxmvvm:Interaction.Behaviors>
                    <dxmvvm:ViewInjectionService RegionName="{x:Static common:Regions.Main}"/>
                </dxmvvm:Interaction.Behaviors>
            </dxwui:FlipView>
        </dx:LoadingDecorator>
    </Grid>
</UserControl>

Inject items to the TileBar

C#

public partial class App : Application {
    private void Application_Startup(object sender, StartupEventArgs e) {
        InitModules();
        …
    }
    private void InitModules() {
        ViewInjectionManager.Default.Inject(
            Regions.Navigation, 
            ModuleType.Customers, 
            () => NavigationItemViewModel.Create(…), 
            typeof(NavigationItemView)
        );
        ViewInjectionManager.Default.Inject(
            Regions.Navigation, 
            ModuleType.Sales, 
            () => NavigationItemViewModel.Create(…), 
            typeof(NavigationItemView)
        );
        ViewInjectionManager.Default.Inject(
            Regions.Navigation, 
            ModuleType.Products, 
            () => NavigationItemViewModel.Create(…), 
            typeof(NavigationItemView)
        );
        …
        ViewInjectionManager.Default.Navigate(Regions.Navigation, ModuleType.Customers);
        …                       
    }
}

VB.NET

Partial Public Class App
    Inherits Application
    Private Sub Application_Startup(ByVal sender As Object, ByVal e As StartupEventArgs)
        InitModules()
        ...
    End Sub
    Private Sub InitModules()
        ViewInjectionManager.Default.Inject(
            Regions.Navigation, 
            ModuleType.Customers, 
            Function() NavigationItemViewModel.Create(
                "Customers", 
                New BitmapImage(
                    New Uri("../Images/Customers.png",UriKind.RelativeOrAbsolute)
                ), 
                ModuleType.Customers
            ), 
            GetType(NavigationItemView)
        )
        ViewInjectionManager.Default.Inject(
            Regions.Navigation, 
            ModuleType.Sales, 
            Function() NavigationItemViewModel.Create(
                "Sales", 
                New BitmapImage(
                    New Uri("../Images/Sales.png", UriKind.RelativeOrAbsolute)
                ), 
                ModuleType.Sales
            ), 
            GetType(NavigationItemView)
        )
        ViewInjectionManager.Default.Inject(
            Regions.Navigation, 
            ModuleType.Products, 
            Function() NavigationItemViewModel.Create(
                "Products", 
                New BitmapImage(
                    New Uri("../Images/Products.png", UriKind.RelativeOrAbsolute)
                ), 
                ModuleType.Products
            ), 
            GetType(NavigationItemView)
        )
        ...
        ViewInjectionManager.Default.Navigate(Regions.Navigation, ModuleType.Customers)
    End Sub
End Class

The example application is almost ready. Synchronize the TileBar and FlipView, so they show the same element. To do this, use the RegisterNavigatedEventHandler.

C#

public class CustomersViewModel {
    …
    protected CustomersViewModel() {
        …
        ViewInjectionManager.Default.RegisterNavigatedEventHandler(this, () => {
            ViewInjectionManager.Default.Navigate(Regions.Navigation, ModuleType.Customers);
        });
    }
    …
}
public class NavigationItemViewModel {   
    …
    protected NavigationItemViewModel() {
        ViewInjectionManager.Default.RegisterNavigatedEventHandler(this, () => {
            ViewInjectionManager.Default.Navigate(Regions.Main, ModuleType);
        });
    }
    …
}

VB.NET

Public Class CustomersViewModel
    ...
    Protected Sub New()
        Content = "A representation of CustomersViewModel."
        ViewInjectionManager.Default.RegisterNavigatedEventHandler(Me, Sub() ViewInjectionManager.Default.Navigate(Regions.Navigation, ModuleType.Customers))
    End Sub
    ...
End Class
...
Public Class NavigationItemViewModel
    ...
    Protected Sub New()
        ViewInjectionManager.Default.RegisterNavigatedEventHandler(Me, Sub() ViewInjectionManager.Default.Navigate(Regions.Main, ModuleType))
    End Sub
    ...
End Class

By default, ViewInjectionService supports a fixed number of standard and DevExpress controls. However if necessary, you can extend it to work with your own controls. To learn how to do it, refer to Implementing Custom Strategy.

Example

View Example

Application.xaml.vb

Imports DevExpress.Mvvm
Imports DXSample.Common
Imports DXSample.View
Imports DXSample.ViewModel
Imports System
Imports System.Windows
Imports System.Windows.Media.Imaging

Namespace DXSample
    Partial Public Class App
        Inherits Application

        Private Sub Application_Startup(ByVal sender As Object, ByVal e As StartupEventArgs)
            InitModules()
            DevExpress.Xpf.Core.ApplicationThemeHelper.UpdateApplicationThemeName()
        End Sub
        Private Sub InitModules()
            ViewInjectionManager.Default.Inject(Regions.Navigation, ModuleType.Customers, Function() NavigationItemViewModel.Create("Customers", New BitmapImage(New Uri("../Images/Customers.png", UriKind.RelativeOrAbsolute)), ModuleType.Customers), GetType(NavigationItemView))
            ViewInjectionManager.Default.Inject(Regions.Navigation, ModuleType.Sales, Function() NavigationItemViewModel.Create("Sales", New BitmapImage(New Uri("../Images/Sales.png", UriKind.RelativeOrAbsolute)), ModuleType.Sales), GetType(NavigationItemView))
            ViewInjectionManager.Default.Inject(Regions.Navigation, ModuleType.Products, Function() NavigationItemViewModel.Create("Products", New BitmapImage(New Uri("../Images/Products.png", UriKind.RelativeOrAbsolute)), ModuleType.Products), GetType(NavigationItemView))
            ViewInjectionManager.Default.Inject(Regions.Main, ModuleType.Customers, Function() CustomersViewModel.Create(), GetType(CustomersView))
            ViewInjectionManager.Default.Inject(Regions.Main, ModuleType.Sales, Function() SalesViewModel.Create(), GetType(SalesView))
            ViewInjectionManager.Default.Inject(Regions.Main, ModuleType.Products, Function() ProductsViewModel.Create(), GetType(ProductsView))

            ViewInjectionManager.Default.Navigate(Regions.Navigation, ModuleType.Customers)
            ViewInjectionManager.Default.Navigate(Regions.Main, ModuleType.Customers)

        End Sub
    End Class

End Namespace

CustomersView.xaml

<UserControl x:Class="DXSample.View.CustomersView"
    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">
    <Grid Background="YellowGreen">
        <TextBlock Text="{Binding Content}" VerticalAlignment="Center" HorizontalAlignment="Center" />
    </Grid>
</UserControl>

Common.vb

Namespace DXSample.Common
    Public Enum ModuleType
        Customers
        Sales
        Products
    End Enum

    Public NotInheritable Class Regions

        Private Sub New()
        End Sub

        Public Shared ReadOnly Property Main() As String
            Get
                Return "MainRegion"
            End Get
        End Property
        Public Shared ReadOnly Property Navigation() As String
            Get
                Return "NavigationRegion"
            End Get
        End Property
    End Class
End Namespace

MainView.xaml

<UserControl x:Class="DXSample.View.MainView"
    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"
    xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
    xmlns:dxwui="http://schemas.devexpress.com/winfx/2008/xaml/windowsui"
    xmlns:dxui="http://schemas.devexpress.com/winfx/2008/xaml/navigation"
    xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm"
    xmlns:common="clr-namespace:DXSample.Common"
    xmlns:v="clr-namespace:DXSample.View">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <dxui:TileBar Padding="10">
            <dxmvvm:Interaction.Behaviors>
                <dxmvvm:ViewInjectionService RegionName="{x:Static common:Regions.Navigation}" />
            </dxmvvm:Interaction.Behaviors>
        </dxui:TileBar>
        <dx:LoadingDecorator Grid.Row="1" >
            <dxwui:FlipView>
                <dxmvvm:Interaction.Behaviors>
                    <dxmvvm:ViewInjectionService RegionName="{x:Static common:Regions.Main}"/>
                </dxmvvm:Interaction.Behaviors>
            </dxwui:FlipView>
        </dx:LoadingDecorator>
    </Grid>
</UserControl>

CustomersViewModel.vb

Imports DevExpress.Mvvm
Imports DevExpress.Mvvm.POCO
Imports DXSample.Common

Namespace DXSample.ViewModel
Public Class CustomersViewModel
    Public Property Content() As String

    Protected Sub New()
        Content = "A representation of CustomersViewModel."
        ViewInjectionManager.Default.RegisterNavigatedEventHandler(Me, Sub() ViewInjectionManager.Default.Navigate(Regions.Navigation, ModuleType.Customers))
    End Sub
    Public Shared Function Create() As CustomersViewModel
        Return ViewModelSource.Create(Function() New CustomersViewModel())
    End Function
End Class
End Namespace

App.xaml.cs

using DevExpress.Mvvm;
using DXSample.Common;
using DXSample.View;
using DXSample.ViewModel;
using System;
using System.Windows;
using System.Windows.Media.Imaging;

namespace DXSample {
    public partial class App : Application {
        private void Application_Startup(object sender, StartupEventArgs e) {
            InitModules();
            DevExpress.Xpf.Core.ApplicationThemeHelper.UpdateApplicationThemeName();
        }
        private void InitModules() {
            ViewInjectionManager.Default.Inject(
                Regions.Navigation, 
                ModuleType.Customers, 
                () => NavigationItemViewModel.Create("Customers", new BitmapImage(new Uri(@"../Images/Customers.png", UriKind.RelativeOrAbsolute)), ModuleType.Customers), 
                typeof(NavigationItemView)
            );
            ViewInjectionManager.Default.Inject(
                Regions.Navigation, 
                ModuleType.Sales, 
                () => NavigationItemViewModel.Create("Sales", new BitmapImage(new Uri(@"../Images/Sales.png", UriKind.RelativeOrAbsolute)), ModuleType.Sales), 
                typeof(NavigationItemView)
            );
            ViewInjectionManager.Default.Inject(
                Regions.Navigation, 
                ModuleType.Products, 
                () => NavigationItemViewModel.Create("Products", new BitmapImage(new Uri(@"../Images/Products.png", UriKind.RelativeOrAbsolute)), ModuleType.Products), 
                typeof(NavigationItemView)
            );
            ViewInjectionManager.Default.Inject(Regions.Main, ModuleType.Customers, () => CustomersViewModel.Create(), typeof(CustomersView));
            ViewInjectionManager.Default.Inject(Regions.Main, ModuleType.Sales, () => SalesViewModel.Create(), typeof(SalesView));
            ViewInjectionManager.Default.Inject(Regions.Main, ModuleType.Products, () => ProductsViewModel.Create(), typeof(ProductsView));

            ViewInjectionManager.Default.Navigate(Regions.Navigation, ModuleType.Customers);
            ViewInjectionManager.Default.Navigate(Regions.Main, ModuleType.Customers);

        }
    }

}

CustomersViewModel.cs

using DevExpress.Mvvm;
using DevExpress.Mvvm.POCO;
using DXSample.Common;

namespace DXSample.ViewModel {
public class CustomersViewModel {
    public string Content { get; set; }

    protected CustomersViewModel() {
        Content = "A representation of CustomersViewModel.";
        ViewInjectionManager.Default.RegisterNavigatedEventHandler(this, () => {
            ViewInjectionManager.Default.Navigate(Regions.Navigation, ModuleType.Customers);
        });
    }
    public static CustomersViewModel Create() {
        return ViewModelSource.Create(() => new CustomersViewModel());
    }
}
}

Common.cs

namespace DXSample.Common {
    public enum ModuleType { 
        Customers, 
        Sales, 
        Products 
    }

    public static class Regions {
        public static string Main { get { return "MainRegion"; } }
        public static string Navigation { get { return "NavigationRegion"; } }
    }
}