Autofac.Core.DependencyResolutionException ViewModel has not been registered Autofac Xamarin.Forms - xamarin

Question

Hey everyone I am using Autofac as my DI codebase Im following this solution Using Navigation in MasterDetailPage with Autofac and Xamarin.Forms since my Press button in tabbedPage cannot navigate to next page or link page. using Button={Binding MyNextPage} in xaml.
in that solution I am a little bit confuse about this
builder.RegisterInstance<Func<Page>>(() => ((NavigationPage)Application.Current.MainPage).CurrentPage);
As my Module I register them individually
public class ClientModule : Module
{
//Register Here for Singleton
protected override void Load(ContainerBuilder builder)
{
//RegServ Service
builder.RegisterType<PersonInfoService>().As<IPersonInfoService>().SingleInstance();
builder.RegisterType<PhoneContactService>().As<IPhoneContacts>().SingleInstance();
//RegServ View Model
builder.RegisterType<PersonViewModel>();
builder.RegisterType<PhoneContactViewModelProp>();
builder.RegisterType<LoginViewModel>();
builder.RegisterType<LoginPageViewModel>().SingleInstance();
builder.RegisterType<PersonsViewModel>().SingleInstance();
builder.RegisterType<PersonDetailViewModel>().SingleInstance();
builder.RegisterType<RegistrationViewModel>().SingleInstance();
builder.RegisterType<PhoneContactViewModel>().SingleInstance();
builder.RegisterType<MainPageViewModel>().SingleInstance();
//RegServ Views
builder.RegisterType<MainPage>().SingleInstance();
builder.RegisterType<BarcodePage>().SingleInstance();
builder.RegisterType<CustomScanPageView>().SingleInstance();
builder.RegisterType<CQRCodeOptionPage>().SingleInstance();
builder.RegisterType<PersonPageView>().SingleInstance();
builder.RegisterType<PersonDetailViewPage>().SingleInstance();
builder.RegisterType<RegistrationPage>().SingleInstance();
builder.RegisterType<ClientReadQRPage>().SingleInstance();
builder.RegisterType<LoginPage>().SingleInstance();
builder.RegisterType<PhoneBookPage>().SingleInstance();
}
}
AutofacBootstrapper.cs
namespace FormsSample.Core
{
public abstract class AutofacBootstrapper
{
public void Run()
{
var builder = new ContainerBuilder();
ConfigureContainer(builder);
var container = builder.Build();
var viewFactory = container.Resolve<IViewFactory>();
RegisterViews(viewFactory);
ConfigureApplication(container);
}
protected virtual void ConfigureContainer(ContainerBuilder builder)
{
builder.RegisterModule<AutofacModule>();
}
protected abstract void RegisterViews(IViewFactory viewFactory);
protected abstract void ConfigureApplication(IContainer container);
}
}
AutofacModule.cs
namespace FormsSample.Core
{
public class AutofacModule : Module
{
protected override void Load(ContainerBuilder builder)
{
// service registration
builder.RegisterType<ViewFactory>()
.As<IViewFactory>()
.SingleInstance();
builder.RegisterType<Navigator>()
.As<INavigator>()
.SingleInstance();
// navigation registration
builder.Register<INavigation>(context =>
App.Current.MainPage.Navigation
).SingleInstance();
}
}
}
Bootstrapper.cs
namespace FormsSample.Core
{
public class Bootstrapper : AutofacBootstrapper
{
private readonly App _application;
public Bootstrapper(App application)
{
_application = application;
}
protected override void ConfigureContainer(ContainerBuilder builder)
{
base.ConfigureContainer(builder);
builder.RegisterModule<ClientModule>();
// builder.RegisterInstance<Func<Page>>(() => ((NavigationPage)Application.Current.MainPage).CurrentPage);
}
protected override void RegisterViews(IViewFactory viewFactory)
{
// register these with the view factory. ViewModel and View Page
//Autofac <object class, Func<class, >
viewFactory.Register<PersonsViewModel, PersonPageView>();
viewFactory.Register<PersonDetailViewModel, PersonDetailViewPage>();
viewFactory.Register<LoginPageViewModel, LoginPage>();
viewFactory.Register<RegistrationViewModel, RegistrationPage>();
viewFactory.Register<PhoneContactViewModel, PhoneBookPage>();
viewFactory.Register<MainPageViewModel, MainPage>();
}
protected override void ConfigureApplication(IContainer container)
{
// set main page
var viewFactory = container.Resolve<IViewFactory>();
var mainPage = viewFactory.Resolve<MainPageViewModel>();
var navigationPage = new NavigationPage(mainPage);
_application.MainPage = navigationPage;
}
}
}

Answer 1

You are saying
When I replace my entire module using ...
When you actually replace your whole module with the single registration the exception explains itself. Autofac can't resolve the MainPageViewModel since it has not been registered.
You have to register your module and the function that resolves the current page:
builder.RegisterModule<ClientModule>();
builder.RegisterInstance<Func<Page>>(() => ((NavigationPage)Application.Current.MainPage).CurrentPage);
Update 1
Following your last comment, I would expect the Bootstrapper to look like this:
public class Bootstrapper
{
public static void Run()
{
var builder = new ContainerBuilder();
builder.RegisterModule<ClientModule>();
builder.RegisterInstance<Func<Page>>(() => ((NavigationPage)Application.Current.MainPage).CurrentPage);
var container = builder.Build();
var page = container.Resolve<MainPage>();
YourApp.Current.MainPage = new NavigationPage(page);
}
}
Update 2
Given your example I think it should work if you do not comment out the third line in your ConfigureContainer method:
protected override void ConfigureContainer(ContainerBuilder builder)
{
base.ConfigureContainer(builder);
builder.RegisterModule<ClientModule>();
builder.RegisterInstance<Func<Page>>(() => ((NavigationPage)Application.Current.MainPage).CurrentPage);
}