Silverlight 2 and the MVP Pattern - silverlight

Any ideas on how i get MVP working with Silverlight? How Do I get around the fact there is no load event raised?
This the view I have:
public partial class Person: IPersonView
{
public event RoutedEventHandler Loaded;
public Person()
{
new PersonPresenter(this);
InitializeComponent();
}
public Person Person
{
set { Person.ItemsSource = value; }
}
}
And my presenter:
public class PersonPresenter
{
private readonly IPersonView _view;
private readonly ServiceContractClient _client;
public PersonPresenter(IPersonView view)
{
_client = new ServiceContractClient();
_view = view;
WireUpEvents();
}
private void WireUpEvents()
{
_view.Loaded += Load;
}
private void Load(object sender, EventArgs e)
{
_client.GetPersonCompleted += Client_GetPerson;
_client.GetPersonAsync();
}
private void Client_GetPerson(object sender, GetPersonCompletedEventArgs e)
{
_view.Person= e.Result;
}
}
Nothing happened for me as the Loaded event dont seem to get called, how do i get around this?

Tim Ross has a good introduction to Silverlight MVP implementation, with source code.

I believe the loaded event gets called when the control has been initialized, loaded, rendered and ready for use. This means that as long as you don't place it inside a visible container (so that it is rendered), the loaded event won't be risen.

You may consider using MVC# - a Model View Presenter framework with Silverlight 2.0 support.
Oleg Zhukov

Related

Open new window on click in WPF, Ninject and Caliburn.Micro

I'm trying to set up a WPF app to call the new window on a menu click with the data provider interface injected into the new viewmodel.
Followed many tutorials and created the Bootstrapper for Caliburn, a service locator and module for ninject. So far the main view doesn't need the IDataProvider but I'd like to open a new window on click event.
The Bootstrapper:
public class Bootstrapper : BootstrapperBase
{
public Bootstrapper()
{
Initialize();
}
protected override void OnStartup(object sender, StartupEventArgs e)
{
DisplayRootViewFor<MainScreenViewModel>();
}
}
The Service Locator and Module:
public class ServiceLocator
{
private readonly IKernel _kernel;
public ServiceLocator()
{
_kernel = new StandardKernel(new ServiceModule());
}
public MainScreenViewModel MainScreenViewModel => _kernel.Get<MainScreenViewModel>();
public NewLayoutViewModel NewLayoutViewModel => _kernel.Get<NewLayoutViewModel>();
}
public class ServiceModule : NinjectModule
{
public override void Load()
{
Bind<ISqlite>().To<Sqlite>();
Bind<IDataProvider>().To<DataProvider>();
}
}
And this is where I got stuck:
public class MainScreenViewModel : Conductor<object>
{
private IWindowManager _windowManager;
public MainScreenViewModel()
{
_windowManager = new WindowManager();
}
public void NewLayout()
{
_windowManager.ShowWindow(new NewLayoutViewModel());
}
}
since the NewLayoutViewModel requires the IDataProvider.
Not sure, what am I missing, but in my understanding Ninject should take care of this di for NewLayoutViewModel.
Found a good solution from Tim Corey on YouTube.
Basically the answer is, if you not insist Ninjet, use Caliburn.Micro's build-in DI solution "SimpleContainer".

Frame ContentLoaded event

I'm new at Silverlight.
I've created a sort of master page using a Page with a frame where the content is loaded. As I handle multiple UserControls at the time (only one is shown, but I want to keep the state of the opened before) I'm setting Content property instead of Navigate method. That way I can assign a UserControl (already created, not a new one as it would be using Navigate with the Uri to the UserControl).
Now I want to take a picture as shown here from the frame when its content changes. If I do it immediately when the content set, the UserControl won't be shown in the picture because it takes a few secs. Frames have the event Navigated, but it doesn't fire with property Content (it just fires when the method Navigate is used, as it name says).
How can I know when new Content is loaded?
If it helps I'm using Silverligh 5.
I've a solution but I don't really like it, so I'm still looking for other ways.
public class CustomFrame : Frame
{
private readonly RoutedEventHandler loadedDelegate;
public static readonly DependencyProperty UseContentInsteadNavigationProperty =
DependencyProperty.Register("UseContentInsteadNavigation", typeof (bool), typeof (CustomFrame), new PropertyMetadata(true));
public bool UseContentInsteadNavigation
{
get { return (bool)GetValue(UseContentInsteadNavigationProperty); }
set { SetValue(UseContentInsteadNavigationProperty, value); }
}
public CustomFrame()
{
this.loadedDelegate = this.uc_Loaded;
}
public new object Content
{
get { return base.Content; }
set
{
if (UseContentInsteadNavigation)
{
FrameworkElement fe = (FrameworkElement)value;
fe.Loaded += loadedDelegate;
base.Content = fe;
}
else
{
base.Content = value;
}
}
}
void uc_Loaded(object sender, RoutedEventArgs e)
{
((UserControl)sender).Loaded -= loadedDelegate;
OnContentLoaded();
}
public delegate void ContentLoadedDelegate(Frame sender, EventArgs e);
public event ContentLoadedDelegate ContentLoaded;
private void OnContentLoaded()
{
if (ContentLoaded != null)
ContentLoaded(this, new EventArgs());
}
}

Unity: Problem with resolving RIA DomainContext

I am using PRISM 4 and got my head around almost all features, however as soon as I would like to inject my DomainContext class (RIA) into my view model, the hell breaks loose. :) It would be great if an experienced Unity/Prism developer could give me an advice how to proceed.
Within my bootstrapper, I am registering the required class in Unity Container like this:
protected override void ConfigureContainer()
{
base.ConfigureContainer();
Container.RegisterType<SCMDomainContext>();
}
Within the NavigationModule, I have the following in the ctor to register the NavigationView with a particular region.
public NavigationModule(IUnityContainer container, IRegionManager regionManager)
{
_container = container;
_regionManager = regionManager;
_regionManager.RegisterViewWithRegion(Constants.NavRegion, () => _container.Resolve<NavigationView>());
}
The View takes the View Model as dependency:
public NavigationView(NavigationViewModel viewModel)
{
InitializeComponent();
Loaded += (s, e) =>
{
DataContext = viewModel;
};
}
The ViewModel has the following:
public NavigationViewModel(SCMDomainContext context)
{
_context = context;
ConstructCommon();
}
As soon as I comment this ctor out and put a en empty ctor, it is all fine, for some reason I can't resolve the SCMDomainContext class. Which is the one you add to have the Domain Context created for you provided by Ria Services.
Since I am using Silverlight, I can't see the stack trace to follow the exception, all I get is this message on a page. What am I missing please?
Microsoft JScript runtime error: Unhandled Error in Silverlight Application An exception occurred while initializing module 'NavigationModule'.
- The exception message was: Activation error occured while trying to get instance of type NavigationModule, key ''
Check the InnerException property of the exception for more information. If the exception occurred
while creating an object in a DI container, you can exception.GetRootException() to help locate the
root cause of the problem. at Microsoft.Practices.Prism.Modularity.ModuleInitializer.HandleModuleInitializationError(ModuleInfo moduleInfo, String assemblyName, Exception exception)
at Microsoft.Practices.Prism.Modularity.ModuleInitializer.Initialize(ModuleInfo moduleInfo)
at Microsoft.Practices.Prism.Modularity.ModuleManager.LoadModulesThatAreReadyForLoad()
at Microsoft.Practices.Prism.Modularity.ModuleManager.IModuleTypeLoader_LoadModuleCompleted(Object sender, LoadModuleCompletedEventArgs e)
at Microsoft.Practices.Prism.Modularity.XapModuleTypeLoader.RaiseLoadModuleCompleted(LoadModuleCompletedEventArgs e)
at Microsoft.Practices.Prism.Modularity.XapModuleTypeLoader.HandleModuleDownloaded(DownloadCompletedEventArgs e)
at Microsoft.Practices.Prism.Modularity.XapModuleTypeLoader.IFileDownloader_DownloadCompleted(Object sender, DownloadCompletedEventArgs e)
at Microsoft.Practices.Prism.Modularity.FileDownloader.WebClient_OpenReadCompleted(Object sender, OpenReadCompletedEventArgs e)
at System.Net.WebClient.OnOpenReadCompleted(OpenReadCompletedEventArgs e)
at System.Net.WebClient.OpenReadOperationCompleted(Object arg)
Your help on this is highly appreciated,
Kave
I can't see much wrong here. But having said that, I'm using the Initialize method from the interface in the following way to register types and views for regions:
#region properties
[Dependency]
public IUnityContainer Container { get; set; }
[Dependency]
public IRegionManager RegionManager { get; set; }
#endregion
public virtual void Initialize()
{
this.Container.RegisterType<NavigationViewModel>(new ContainerControlledLifetimeManager());
this.Container.RegisterType<NavigationView>(new ContainerControlledLifetimeManager());
this.RegionManager.RegisterViewWithRegion(Constants.NavRegion, () => this.Container.Resolve<NavigationView>());
}
Not sure whether it makes a difference if you don't explicitly register the ViewModel and the View type. Personally I prefer to have control over the way how a type gets resolved by the container.
In fact its best to create a layer for the DomainContext like this. Then its easily resolvable by an IoC:
public class ContactModuleService : IContactModuleService
{
readonly SCMDomainContext _context = new SCMDomainContext();
#region Implementation of IContactModuleService
public EntitySet<Contact> Contacts
{
get { return _context.Contacts; }
}
public EntityQuery<Contact> GetContactsQuery()
{
return _context.GetContactsQuery();
}
public SubmitOperation SubmitChanges(Action<SubmitOperation> callback, object userState)
{
return _context.SubmitChanges(callback, userState);
}
public SubmitOperation SubmitChanges()
{
return _context.SubmitChanges();
}
public LoadOperation<TEntity> Load<TEntity>(EntityQuery<TEntity> query, Action<LoadOperation<TEntity>> callback, object userState) where TEntity : Entity
{
return _context.Load(query, callback, userState);
}
public LoadOperation<TEntity> Load<TEntity>(EntityQuery<TEntity> query) where TEntity : Entity
{
return _context.Load(query);
}
#endregion
}

How to get the popup to go full screen?

I am currently experimenting with the ChildWindowDialog and with prism I have created a controller class. I would like my popup to be displayed on all the screen (a bit like fullscreen mode). I have HtmlPage.Window.Eval() below but I am not sure if this is the correct thing to do. One of the reasons it feels wrong is I have no idea how to test this class in the future. Also, I have coupled the controller to the Browser class which will mean I could not reuse it in a WPF app.
public class GalleryCoverFlowChildWindowController
{
private readonly IEventAggregator _eventAggregator;
private readonly IUnityContainer _container;
public GalleryCoverFlowChildWindowController(IEventAggregator eventAggregator, IUnityContainer container)
{
_eventAggregator = eventAggregator;
_container = container;
_eventAggregator.GetEvent<GalleryCoverViewPopupEvent>().Subscribe(PopupShow, ThreadOption.UIThread, true, Filter);
}
private bool Filter(string obj)
{
return true;
}
private void PopupShow(string obj)
{
var galleryPopup = _container.Resolve<GalleryCoverFlowChildWindow>();
galleryPopup.Width = (double)System.Windows.Browser.HtmlPage.Window.Eval("screen.availWidth");
galleryPopup.Height = (double)System.Windows.Browser.HtmlPage.Window.Eval("screen.availHeight");
galleryPopup.Show();
}
}
JD.
To resolve the issue with coupling, I created a ScreenService and injected it in via Unity. That way I do not have a dependency on DOM. This will make testing the code easier.
Any thoughts?

Threading problem in WPF

I'm getting this Exception
System.InvalidOperationException was
unhandled by user code Message="The
calling thread cannot access this
object because a different thread owns
it."
whenever I run the following code
public partial class MainScreen : Window
{
Timer trm;
public MainScreen()
{
InitializeComponent();
trm = new Timer(1000);
trm.AutoReset = true;
trm.Start();
trm.Elapsed += new ElapsedEventHandler(trm_Elapsed);
}
void trm_Elapsed(object sender, ElapsedEventArgs e)
{
lblTime.Content = System.DateTime.Now;
}
}
guys any solution... I badly wann come out of it :(
Use DispatcherTimer instead:
public partial class MainScreen : Window{
DispatcherTimer tmr;
public MainScreen() {
InitializeComponent();
tmr = new DispatcherTimer();
tmr.Tick += new EventHandler(tmr_Tick);
tmr.Start();
}
void tmr_Tick(object sender, EventArgs e) {
lblTime.Content = System.DateTime.Now;
}
}
Any time you modify Windows controls you must do so on the UI thread (the one that created the controls).
See this question for lots of details.
To be short, you should use Dispatcher.Invoke method to update UI elements.

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