Question

How can I inject my CustomerRepository into my CustomerVM view model? In my view, a WPF Page I have:

<Page.DataContext>
    <viewModel:CustomerVM/>
</Page.DataContext>

But my view model constructor obviously has parameter passed in,

    public CustomerVM(ICustomerRepository customerRepository)
    {
        //this._customerRepository = customerRepository;
    }

I get

Type ‘CustomerVM’ is not usable as an object element because it is not
public or does not define a public parameterless constructor or a type
converter.

Really struggling to heck.

Any help appreciated.

Answer 1

I don’t think you can initialize the DataContext within the XAML if you’re using dependency injection. Set the DataContext in the code-behind for the view so Unity can resolve the dependencies. Try adding this to YourView.xaml.cs:

public YourView(CustomerVM viewModel)
{
    InitializeComponent();

    this.DataContext = viewModel;
}

The above will work if you are resolving your views through Unity. If not, you can also use the ServiceLocator to resolve the view model:

using Microsoft.Practices.ServiceLocation;

public YourView()
{
    InitializeComponent();

    this.DataContext = ServiceLocator.Current.GetInstance<CustomerVM>();
}

You might also need to add the following somewhere in your registration code to setup the ServiceLocator if you’re not using Prism:

ServiceLocator.SetLocatorProvider(new ServiceLocatorProvider(() => new UnityServiceLocator(_unityContainer)));