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 48,256 Microsoft Vendor

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 48,256 Reputation points Microsoft Vendor

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?

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