xaml mvvm efcore IOC

Question

xaml mvvm efcore IOC

PharmaSoft 1

Hello

In IOC, I have this exemple in the modelview

public ReqCaisse(IDataContext database)
{
    dataBase = database;
}

and from the view, it creates a new modelview

<b:Interaction.Triggers>
    <b:EventTrigger EventName="Loaded">
        <b:CallMethodAction MethodName="LoadView" TargetObject="{StaticResource ResourceKey=CaisseRows}" />
    </b:EventTrigger>
</b:Interaction.Triggers>

so I have to put then static property for dataBase public static IDataContext dataBase;

Could you tell me how I can do it without using the static ? I know it is not from devexpress tools but i could help me if you give me somme infos I had this page https://community.devexpress.com/blogs/wpf/archive/2022/02/07/dependency-injection-in-a-wpf-mvvm-application.aspx but not enough infos for me Thanks a lot

Hui Liu-MSFT 48,711 Microsoft External Staff

Hi,@PharmaSoft.Welcome Microsoft Q&A. For the problem of avoiding using a static property for the database, you could follow a proper MVVM and IoC design pattern. You can try the following steps:

ViewModel Constructor with Dependency Injection:

Modify your ReqCaisse ViewModel to accept IDataContext through its constructor, as you've already done:

public class ReqCaisseViewModel
{
    private readonly IDataContext dataBase;

    public ReqCaisseViewModel(IDataContext database)
    {
        dataBase = database;
    }

    // Other view model properties and methods
}

XAML Binding:

In your XAML, set up your view to use the ViewModel, and use an IoC container to manage the ViewModel lifecycle and resolve dependencies.

<Window x:Class="YourNamespace.MainWindow"
      ...
        xmlns:local="clr-namespace:YourNamespace"
        xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity">
    <Window.DataContext>
        <local:ReqCaisseViewModel/>
    </Window.DataContext>

    <!-- Your Window layout -->

    <i:Interaction.Triggers>
        <i:EventTrigger EventName="Loaded">
            <i:InvokeCommandAction Command="{Binding LoadViewCommand}" />
        </i:EventTrigger>
    </i:Interaction.Triggers>
</Window>

IoC Container Setup:

First, ensure that you have set up your IoC container correctly to register and resolve the IDataContext interface (presumably an Entity Framework Core DbContext).



var builder = new ContainerBuilder();

// Register your IDataContext implementation as a singleton
builder.RegisterType<YourDataContext>().As<IDataContext>().SingleInstance();

// Register your view models, services, and other dependencies
builder.RegisterType<ReqCaisseViewModel>();
// Register other dependencies as needed

// Build the container
var container = builder.Build();

ViewModel Initialization:

In your ReqCaisseViewModel, you can use an ICommand to handle the Loaded event and perform the necessary initialization when the view is loaded:


public class ReqCaisseViewModel : ViewModelBase
{
    private readonly IDataContext dataBase;

    public ICommand LoadViewCommand { get; private set; }

    public ReqCaisseViewModel(IDataContext database)
    {
        dataBase = database;
        LoadViewCommand = new DelegateCommand(Initialize);
    }

    private void Initialize()
    {
        // Perform initialization when the view is loaded
    }

    // Other view model properties and methods
}

PharmaSoft 1 Reputation point

2023-09-09T09:20:59.85+00:00
Hello,

Thank you, it works but... this

<Window.DataContext> <local:ReqCaisseViewModel/> </Window.DataContext>

trigger the constructor reqCaisseViewModel creating an empty one???

public ReqCaisseViewModel() { }

so the command don't fire

If I put the DataContext = reqcaisse in code behind, it works

do I make something wrong with the Ioc ?
PharmaSoft 1 Reputation point

2023-09-09T09:30:15.18+00:00

PS : it is a usercontrol and the reqCaisseViewmodel is injected in the windows container

that is why I have to put the datacontext in the codebehind.

I've read that should use Host but I don't how ?
Hui Liu-MSFT 48,711 Reputation points Microsoft External Staff

2023-09-18T08:31:40.1966667+00:00

Hi,@PharmaSoft. I see the thread datacontext from IOC you posted and it seems that you have solved it. Has this issue of yours been resolved as well?

Your answer

PharmaSoft 1 Reputation point

2023-09-09T09:20:59.85+00:00

Hello,

Thank you, it works but... this

<Window.DataContext> <local:ReqCaisseViewModel/> </Window.DataContext>

trigger the constructor reqCaisseViewModel creating an empty one???

public ReqCaisseViewModel() { }

so the command don't fire

If I put the DataContext = reqcaisse in code behind, it works

do I make something wrong with the Ioc ?
PharmaSoft 1 Reputation point

2023-09-09T09:30:15.18+00:00

PS : it is a usercontrol and the reqCaisseViewmodel is injected in the windows container

that is why I have to put the datacontext in the codebehind.

I've read that should use Host but I don't how ?
Hui Liu-MSFT 48,711 Reputation points Microsoft External Staff

2023-09-18T08:31:40.1966667+00:00

Hi,@PharmaSoft. I see the thread datacontext from IOC you posted and it seems that you have solved it. Has this issue of yours been resolved as well?

Share via

xaml mvvm efcore IOC

Your answer