CODEWITHSUNDEEP
wpfxamldata-bindingmvvmuser-controls
NTinkicht
NTinkicht

Reputation: 1002

ViewModel constructor containing arguments ins WPF

How can we bind a user-control to a view-model object, when this last contains parameters in his constructor ???

Does the binding using "DataContext" in the view ensure that when we create a view-model, the view is automatically created ??

Upvotes: 1

Views: 965

Answers (1)

Omri Btian
Omri Btian

Reputation: 6547

If you are using an IoC container, this is supported out-of-the-box.

It really depends on the IoC container you are using, but here is an example using Prism Unity container.

The following examples are taken out from the Prism QuickStarts guide

So, at first, we will have to set up the unity container:

public class QuickStartBootstrapper : UnityBootstrapper
{
   private readonly CallbackLogger callbackLogger = new CallbackLogger();

    /// <summary>
    /// Configures the <see cref="IUnityContainer"/>. 
    ///May be overwritten in a derived class to add specific
    /// type mappings required by the application.
    /// </summary>
    protected override void ConfigureContainer()
    {
        // Here you can do custom registeration of specific types and instances
        // For example
        this.Container.RegisterInstance<CallbackLogger>(this.callbackLogger);

        base.ConfigureContainer();
    }
}

Baisically, youre done! All you have to do now is have your view recieve the viewModel as a parameter in his constructor, like this:

public partial class OverviewView
{
    public OverviewView(OverviewViewModel viewModel)
    {
        InitializeComponent();
        this.DataContext = viewModel;
    }
}

Unity IoC container will take care of your parameters in the ViewModel even without you having to register those types most of the times.

Please note that in my answer I only refered to the IoC part of the configuration. setting up an entire MVVM application requires a bit more work and varies depending the MVVM framework you are using

Upvotes: 1

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