Skills reuse with xamarin and MVVM - Vincent for reusing dot NET skills... · Title: Skills reuse with xamarin and MVVM - Vincent Author: Mike Fortgens Subject: NLWeb Created Date:

Patterns for reusing .NET skills and code for

iOS, Android and Windows Apps

Vincent Hoogendoorn twitter.com/vincenth_net

Sander Egberink

https://twitter.com/vincenth_net

Agenda

- Introduction

- Demo and code FlyBy BCC App

- MVP+

- MVVM+

- Pattern Comparison

- Next Steps, Resources, Questions

IntroductionOngoing research goal:

“Optimise reuse of .NET code and skills when building native Apps for iOS,

Android, Windows Store and Windows Phone.”

Case App: BCC Veiling – Responsive Design, Azure, SignalR, Complex

Authentication, clients for Mobile Web, iOS, Android and Windows Store

V1: MVP+; in stores.

V2: MVVM+; almost done.

Spoiler: MVVM+ lets a non-mobile .NET developer write most code for you

Demo – BCC App

FlyBy – All the code you need to add 2nd+

platform…

With MVVM+

MVP+ - Overview

Model• Entities (POCOs)

public class Lot{

public int Id { get; set; }public string AuctionTitle { get; set; }public string Title { get; set; }public string Info { get; set; }}

public class LotUpdate{

public decimal ProgressRemaining { get; set; }public decimal CurrentPrice { get; set; }public RemainingTime TimeRemaining { get; set; }

}

MVP+ - Overview

Presenter• Properties

• INotifyPropertyChanged

implemented


public Lot ActiveLot{

get { return _activeLot; }set {

_activeLot = value;NotifyPropertyChanged("ActiveLot"); }

}

public List<Lot> ProductsList{

get { return _productsList; }set {

_productsList = value;NotifyPropertyChanged("ProductsList"); }

}

public event PropertyChangedEventHandlerPropertyChanged;

MVP+ - Overview



implemented


ServiceAgent• Service Methods

• Service Events

• Connection Management

private SignalRConnectionResponseInitialSignalRConnect(){

connection = newHubConnection(serviceInfo.SignalRRootUrl);

proxy = connection.CreateProxy(serviceInfo.SignalRHubName);

proxy.On<Lot>("auctionInitialized", HandleAuctionInitialized);}

private void HandleAuctionInitialized(Lot lot){ MainModel.Current.ActiveLot = lot; }

public void InvokePlaceBid(int lotId, decimallotCurrentPrice){

proxy.Invoke("PlaceBid", new object[] { lotId, lotCurrentPrice });

}

MVP+ - Overview



implemented



• Service Events


View• Markup

• Data binding code

(if not supported in markup)

• UI Manipulation Code

Entry

Point

ServiceAgent.Current.InitiateConnection();

Presenter.Current.PropertyChanged += OnCurrentChanged;private void OnCurrentChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)

{if (e.PropertyName == "ActiveLot"){

Activity.RunOnUiThread(delegate{

FullUIUpdate(); });

}}

private void FullUIUpdate(){

currentProductHeader.Text = Presenter.Current.ActiveLot.Title;

regularStorePrice.Text = Presenter.Current.ActiveLot.RegularPrice.ToString("C");

MVP+ – Application Startup



implemented



• Service Events


View• Markup




Entry

Point

1) Application starts Initial View

2) View calls Service agent constructor which establishes connection

3) ServiceAgent requests initial data and sets listeners for updates

4) ServiceAgent receives data and passes it to the Presenter

5) Presenter’s properties are INotifyPropertyChanged – Being set by

the ServiceAgent raises the event which is caught by View, which

subsequently updates the UI.1

2 3

4

5

MVP+ - Ordering a product



implemented



• Service Events


View• Markup




Entry

Point

ServiceAgent.Current.InvokePlaceBid(Presenter.Current.ActiveLot.Id, Presenter.Current.ActiveLot.UpdateInformation.CurrentPrice);




implemented



• Service Events


View• Markup




Entry

Point

public void InvokePlaceBid(int lotId, decimallotCurrentPrice){

proxy.Invoke("PlaceBid", new object[] { lotId, lotCurrentPrice });

}

proxy.On<Lot>("BidPlaced", BidPlaced);proxy.On("BidFailed", BidFailed);proxy.On("BidFailedOnAuthentication",

BidFailedOnAuthentication);

proxy.On("BidCancelled", BidCancelled);proxy.On("CancelBidFailed", CancelBidFailed);




implemented



• Service Events


View• Markup




Entry

Point

private void BidPlaced(Lot reservedLot){

Presenter.Current.ReservedLot = reservedLot;}




implemented



• Service Events


View• Markup




Entry

Point

private Lot _reservedLot;public Lot ReservedLot{

get { return _reservedLot; }set {

_reservedLot = value;NotifyPropertyChanged("ReservedLot");

}}

public event PropertyChangedEventHandlerPropertyChanged;

private void NotifyPropertyChanged(string propertyName){

var eventHandler = PropertyChanged;if (eventHandler != null) {

eventHandler(this, newPropertyChangedEventArgs(propertyName));

}}




implemented



• Service Events


View• Markup




Entry

Point

Presenter.Current.PropertyChanged += OnCurrentChanged;

private void OnCurrentChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e){if (e.PropertyName == "ReservedLot"){if (null != Presenter.Current.ReservedLot)

{ Activity.RunOnUiThread(delegate{ BuyLot(); }); }}}}

private void BuyLot(){if (null != Presenter.Current.ReservedLot){Intent i = new Intent(Activity,

typeof(FinalizeOrderActivity));StartActivity(i);}

}

MVP+ – Shared Code



implemented



• Service Events


- Entities

- Application-wide Model

(through presenter)

- Application-wide Model

change events

- Service Agent

- Business Logic

MVVM+ ViewModel Properties

ViewModel• Properties

• Commands

• INotifyPropertyChanged,

INotifyCollectionChanged

public decimal ActiveLotCurrentPrice{

get { return _activeLotCurrentPrice; }set{

_activeLotCurrentPrice = value;PropChanged("ActiveLotCurrentPrice");

}}

public bool SigninButtonIsAvailable{

get{

return !_auctionApplication.IsUserLoggedIn();}

}

MVVM+ ViewModel Commands


• Commands



public RelayCommand PlaceBidCommand{ get; private set; }

private void WireupCommands(){

PlaceBidCommand = new RelayCommand(PlaceBid);PlaceBidCommand.IsEnabled = true;…

}

private void PlaceBid(){

ShowReasonForRejection = false;var placeBidRequest = new PlaceBidRequest{

LotId = ActiveLotId,Price = ActiveLotCurrentPrice

};_auctionServiceAgent.RaisePlaceBidAsync(placeBidRequest);

}

MVVM+ ViewModel Data Binding


• Commands



public abstract class ViewModelBase : INotifyPropertyChanged, INotifyCollectionChanged…protected void PropChanged(string propName){

RunOnUIThread(() => OnPropertyChanged(propName));}

public class AuctionViewModel : ViewModelBase…public DateTime AuctionStartsAt{

get { return _auctionStartsAt; }set{

_auctionStartsAt = value;PropChanged("AuctionStartsAt");

}}.

MVVM+ View


• Commands



View• Markup




View development can start at the earliest right after a ViewModel has

its properties and commands defined, and an instance with hardcoded

design time data in the properties is available.

public class AuctionViewModelStub : AuctionViewModel{

public AuctionViewModelStub(){

// Set all base ViewModel properties to// hardcoded values, optionally with random// selection from multiple values or value sets.

}}

View development can start at the latest after all shared code has

been completed.

The View implementation is platform specific. Details for each

platform are shown later in this presentation.

MVVM+ Model Entities


• Commands



Model• Entities (POCO)

View• Markup




public class ClientLotUpdate{

public decimal CurrentPrice { get; set; }public int ProgressRemaining { get; set; }public RemainingTime TimeRemaining { get; set; }

public ClientLotUpdate(){

TimeRemaining = new RemainingTime();}

}

MVVM+ Service Entities


• Commands



ServiceAgent• Service Entities

• Service Events

• Service Methods

View• Markup




public class ClientLotUpdate{

public decimal CurrentPrice { get; set; }public int ProgressRemaining { get; set; }public RemainingTime TimeRemaining { get; set; }

public ClientLotUpdate(){

TimeRemaining = new RemainingTime();}

}

Note that in simple cases service entities defined in the service contract can be used directly as the ‘model’.

MVVM+ Model ServiceAgent Events


• Commands





• Service Events

• Service Methods

View• Markup




public class LotUpdatedEventArgs : EventArgs{

public ClientLotUpdate clientLotUpdate { get; set; }}

public event EventHandler<LotUpdatedEventArgs> ActiveLotUpdated;

MVVM+ Model ServiceAgent Methods


• Commands





• Service Events

• Service Methods

View• Markup




public class PlaceBidRequest{

public int LotId { get; set; }public decimal Price { get; set; }

}

public Task RaisePlaceBidAsync(PlaceBidRequestplaceBidRequest)

{return _hubProxy.Invoke(

"PlaceBid", new object[] { placeBidRequest });

}

MVVM+ ViewModel use of Application


• Commands





• Service Events

• Service Methods

Application• ViewModels instance

• Navigation context

• Navigation transitions

View• Markup




public interface IAuctionApplication{

void ContinueToAuction();void ContinueToCheckout(Basket basket);void ContinueToOrderConfirmed();void ContinueToProductList();void ContinueToProductPage(ClientLot product);void UserWantsToSignIn();bool IsUserLoggedIn();

}

The ViewModel only uses the application to initiate navigation and to obtain relevant application state.

This is not available to ViewModels:

public interface IApplication<TNavigationContext>{

TNavigationContext CurrentNavigationContext { set; }TViewModel GetViewModel<TViewModel>();

}

MVVM+ Application


• Commands





• Service Events

• Service Methods




View• Markup




public class AuctionApplication<TNavigationContext> :IAuctionApplication,IApplication<TNavigationContext>

public void ContinueToCheckout(Basket basket, TNavigationContext navigationContext)

{CheckoutViewModel = new CheckoutViewModel(basket,_auctionServiceAgentBase, this, _taskScheduler);

RunOnUIThread(() =>_auctionNavigator.NavigateToCheckoutView(navigationContext)

);}

Application initializes viewmodel and then calls navigator for platform-specific view navigation.

MVVM+ Application use of Navigator


• Commands





• Service Events

• Service Methods




View• Markup




Navigator• Navigate to view

implementation

public interface IAuctionNavigator<TNavigationContext>{

void NavigateToSignInView(TNavigationContext c);void NavigateToAuctionView(TNavigationContext c);void NavigateToCheckoutView(TNavigationContext c);void NavigateToOrderConfirmed(TNavigationContext c);void NavigateToProductsView(TNavigationContext c);void NavigateToProductNotInAuctionView(

TNavigationContext navigationContext);}

The navigator implementation is platform specific (TNavigationContext)

MVVM+ Application Entry Point for Windows

Store App


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

public static AuctionApplication<Frame> AuctionApplication { get; private set; }

private static void EntryPoint(){

var taskScheduler =TaskScheduler.FromCurrentSynchronizationContext();

AuctionApplication =await AuctionApplication<Frame>.GetInstance(

rootFrame, new AuctionNavigator(), taskScheduler

);

AuctionApplication.Start();}

The entry point is platform specific (TNavigationContext, here a WinRT Frame).

MVVM+ Navigator for Windows Store App


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

public class AuctionNavigator : IAuctionNavigator<Frame>{

public void NavigateToAuctionView(Frame navigationContext)

{navigationContext.Navigate(typeof(AuctionPage));

}

public async void NavigateToOrderConfirmed(Frame navigationContext)

{var dialog = newWindows.UI.Popups.MessageDialog(“Message");await dialog.ShowAsync();NavigateToAuctionView(navigationContext);

}…

}

The navigator is platform specific (TNavigationContext, here a WinRT Frame).

MVVM+ View for Windows Store App – Data

Binding


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

<local:CheckoutViewBasex:Class="MobileAuction.W8.Views.CheckoutView"xmlns:local="using:MobileAuction.W8.Views“d:DataContext="{d:DesignInstance

IsDesignTimeCreatable=True,Type=shared:CheckoutViewModelStub}"

…

<TextBox x:Name="txtVoornaam“Text="{Binding FirstName, Mode=TwoWay}" />

public class Page<TViewModel> : Page{

protected Page(IApplication<Frame> application){

if (application != null) DataContext =application.GetViewModel<TViewModel>();

}}

Note: both design-time and runtime data is supported.

MVVM+ View for Windows Store App – C#


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

<local:CheckoutViewBasex:Class="MobileAuction.W8.Views.CheckoutView"xmlns:local="using:MobileAuction.W8.Views“d:DataContext="{d:DesignInstance

IsDesignTimeCreatable=True,Type=shared:CheckoutViewModelStub}"

…

// This class can be eliminated once the x:TypeArguments // attribute is supported in XAML:// http://stackoverflow.com/questions/14478469/windows-8-store-application-support-for-xtypearguments

public abstract class CheckoutViewBase :Mobile.Presentation.W8.Page<

MobileAuction.Shared.CheckoutViewModel>{

public CheckoutViewBase() :base(App.AuctionApplication) { }

}

MVVM+ Navigator for Android


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

public class AuctionNavigator : IAuctionNavigator<Activity>

{

public void NavigateToCheckoutView(ActivitynavigationContext)

{Intent i = new Intent(navigationContext,

typeof(CheckoutActivity));navigationContext.StartActivity(i);

}

public void NavigateToAuctionView(ActivitynavigationContext)


typeof(HomeActivity));navigationContext.StartActivity(i);

}

MVVM+ View for Android


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

public class Activity<TActivity, TViewModel> : global::Android.Support.V4.App.Activity,

IView<TViewModel> where TActivity : Activity<TActivity, TViewModel>

where TViewModel : INotifyPropertyChanged{

public TViewModel ViewModel { get; set; }

public override void OnCreate(BundlesavedInstanceState)

{base.OnCreate(savedInstanceState);ViewModel =

AuctionApplication<Activity>.GetInstance().GetViewModel<TViewModel>(); }}

MVVM+ View for Android


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

public class SplashScreen : Activity{

protected override void OnCreate(BundlesavedInstanceState)

{base.OnCreate(savedInstanceState);

AuctionApplication<Activity>.GetInstance(this, newAuctionNavigator(), TaskScheduler.FromCurrentSynchronizationContext()).Start(); }}

Note: The initial definition of the AuctionApplication in a view is also the Entry Point

MVVM+ Navigator for iOS


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

public class AuctionNavigator : IAuctionNavigator<UIViewController>

{

public void NavigateToCheckoutView(UIViewController context)

{CheckoutViewController checkoutView =

context.Storyboard.InstantiateViewController ("CheckoutViewController")

as CheckoutViewController;context.NavigationController.PushViewController(checkoutView, false);}

public void NavigateToAuctionView(UIViewController context){context.NavigationController.PopToRootViewController (false);}

}

MVVM+ View for iOS


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

public partial class ViewController<TViewController, TViewModel> : UIViewController, IView<TViewModel>

where TViewController: ViewController<TViewController, TViewModel>



public override void ViewDidLoad (){

ViewModel = AuctionApplication<UIViewController>.GetInstance ().GetViewModel<TViewModel> ();

base.ViewDidLoad ();}

}

MVVM+ View for iOS


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

public partial class AuctionViewController : ViewController<AuctionViewController, AuctionViewModel>{

public AuctionViewController (IntPtr handle) : base(handle)

{InvokeOnMainThread (delegate {

AuctionApplication<UIViewController>.GetInstance (this, new AuctionNavigator (),

TaskScheduler.FromCurrentSynchronizationContext ()).Start ();});

}}

Note: The initial definition of the AuctionApplication in a view is also the Entry Point

MVVM – Composite ViewModels


• Commands



View• Markup





• Commands




• Commands



MVVM – Composite ViewModels Android


public class AuctionFragment : Fragment<AuctionFragment, AuctionViewModel>{

}

public class AuctionFragment : Fragment<AuctionFragment, AuctionViewModel>{

}

public class Fragment<TFragment, TViewModel> : global::Android.Support.V4.App.Fragment, IView<TViewModel> where TFragment : Fragment<TFragment, TViewModel>



public override void OnCreate(Bundle savedInstanceState){

base.OnCreate(savedInstanceState);ViewModel = AuctionApplication<Activity>.GetInstance().GetViewModel<TViewModel>(); }

}


<LinearLayoutandroid:orientation="vertical"android:layout_width=“fill_parent"android:layout_height="fill_parent"android:background="@color/white">

<fragment class="mobile.android.ProductListFragment"android:layout_width=“0dip"android:layout_height="match_parent"android:layout_weight="0.5"/>

<fragment class="mobile.android.ProductListFragment"android:layout_width=“0dip"android:layout_height="match_parent"android:layout_weight="0.5"/>

</LinearLayout>

MVVM – Composite ViewModels iOS

MVVM – Composite ViewModels iOS

public partial class AuctionViewController : ViewController<AuctionViewController, AuctionViewModel>{

}

public partial class ProductListController : DialogViewController<ProductListController, ProductsViewModel>{

}

public partial class ViewController<TViewController, TViewModel> : UIViewController, IView<TViewModel>where TViewController: ViewController<TViewController, TViewModel>



public override void ViewDidLoad (){

ViewModel = AuctionApplication<UIViewController>.GetInstance ().GetViewModel<TViewModel> ();base.ViewDidLoad ();

}}

MVVM – Composite ViewModels iOSAuctionViewController auctionViewController =

UIStoryboard.FromName ("MainStoryboard_iPad", null).InstantiateViewController("AuctionViewController")as AuctionViewController;

AuctionApplication<UIViewController>.GetInstance ().CurrentNavigationContext = this;

UIViewController productsViewController = UIStoryboard.FromName ("MainStoryboard_iPad", null).InstantiateViewController

("ProductListViewController") as UIViewController;

RectangleF rect = this.View.Bounds;rect.Width = rect.Width / 2;

UIView auctionView = auctionViewController.View;auctionView.Frame = new RectangleF (new PointF (0, 0), new SizeF (this.View.Bounds.Width / 2,

this.View.Bounds.Height));

UIView aboutView = productsViewController.View;aboutView.Frame = new RectangleF (new PointF (this.View.Bounds.Width / 2, 0), new SizeF

(this.View.Bounds.Width / 2, this.View.Bounds.Height));

this.View.AddSubviews (new UIView[] { auctionView, aboutView });

this.AddChildViewController (auctionViewController);this.AddChildViewController (productsViewController);

Demo: Windows Store App Composite

ViewModels – Design time


ViewModels – Design time


ViewModels - Runtime

MVVM+ Composite View for Windows Store App

– C#


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

public class UserControl<TViewModel> : UserControl{

protected UserControl(IApplication<Frame> application)

{ if (application != null) DataContext =application.GetViewModel<TViewModel>(); }

}

// This class can be eliminated once the x:TypeArguments attribute is supported in XAML: http://stackoverflow.com/questions/14478469/windows-8-store-application-support-for-xtypeargumentspublic abstract class AuctionViewBase :

Mobile.Presentation.W8.UserControl<MobileAuction.Shared.AuctionViewModel>

{public AuctionViewBase() :

base(App.AuctionApplication) { }}

MVVM+ Composite View for Windows Store App

- XAML


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

<local:AuctionViewBasex:Class="MobileAuction.W8.Views.AuctionView“d:DataContext="{d:DesignInstanceIsDesignTimeCreatable=True,Type=shared:AuctionViewModelStub}"…

<local:ProductsViewBasex:Class="MobileAuction.W8.Views.ProductsView“d:DataContext="{d:DesignInstanceIsDesignTimeCreatable=True,Type=shared:ProductsViewModelStub}"…

<views:AuctionView d:DataContext="{d:DesignInstanceIsDesignTimeCreatable=True,Type=shared:AuctionViewModelStub}" /><views:ProductsView d:DataContext="{d:DesignInstanceIsDesignTimeCreatable=True,Type=shared:ProductsViewModelStub}" />

MVVM+ Runtime flow


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

Runtime flow: Application starts with AuctionView, user places bid and navigates to CheckoutView.1. Entrypoint is called, creates Application instance

and calls Application.Start().

1

MVVM+ Runtime flow


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point


and calls Application.Start().2. Application ctor creates ServiceAgent

Start() creates AuctionViewModel + ProductsViewModel

1

2

2

MVVM+ Runtime flow


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point



Start() creates AuctionViewModel + ProductsViewModel3. Application calls

_auctionNavigator.NavigateToAuctionView()

1

2

3

2

MVVM+ Runtime flow


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point




_auctionNavigator.NavigateToAuctionView()4. Navigator calls platform-specific navigate to

AuctionView

1

2

3

4

2

MVVM+ Runtime flow


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point





AuctionView5. View base class gets ViewModel from Application1

2

3

4

5

2

MVVM+ Runtime flow


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point





AuctionView5. View base class gets ViewModel from Application6. On platforms without native data binding, the view

subscribes itself to PropertyChanged and CollectionChanged on ViewModel, for select (groups of) properties (it is not necessary to bind to each individual property). Also the commands of the views are invoked from code in an event handler.

1

2

3

4

5 6

2

MVVM+ Runtime flow


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point







7. The viewmodel is updated by events from service and commands from view. The view updates w data binding.

1

2

3

4

5 6

72

MVVM+ Runtime flow


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point








8. A command on a viewmodel can invoke the ContinueTo… method on application … continue with step 3.

1

2

3

4

5 6

782

MVVM+ Runtime flow


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point








8. A command on a viewmodel can invoke the ContinueTo… method on application … continue with step 3.

1

2

3

4

5 6

782

MVP+ Shared Code



implemented



• Service Events


MVVM+ Shared Code


• Commands





• Service Events

• Service Methods




View• Markup





implementation

Entry

Point

View• Markup




• Navigation logic

Entry

Point

Pattern Comparison

MVP+ Shared Code MVVM+ Shared Code

Presenter.Current.PropertyChanged += OnCurrentChanged;

private void OnCurrentChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e){if (e.PropertyName == "ReservedLot"){if (null != Presenter.Current.ReservedLot)

{ Activity.RunOnUiThread(delegate{ BuyLot(); }); }}}}

private void BuyLot(){if (null != Presenter.Current.ReservedLot){Intent i = new Intent(Activity,

typeof(FinalizeOrderActivity));StartActivity(i);}

}

View• Markup





• Commands



private void OnBidPlaced(object sender, BidPlacedEventArgs e){

if (e.PlaceBidResult.BidIsAccepted){

var lot = e.PlaceBidResult.Lot;var basket = new Basket{

// Basket Init code here};

_auctionApplication.ContinueToCheckout(basket);}public class AuctionNavigator :

IAuctionNavigator<Activity>{

public void NavigateToCheckoutView(ActivitynavigationContext)


typeof(CheckoutActivity));navigationContext.StartActivity(i);

}

MVP+ Shared Code MVVM+ Shared Code

Android Specific

26%

Shared Code

74%

CODE SHARE

Android Specific

52%

Shared Code

48%

CODE SHARE

Pro/Con of MVP+ versus MVVM+MVP+ MVVM+

Pro • Less total Code – esp for cases

where API matches view closely.

• Simpler pattern to apply

(write)

• First client by single developer takes

less time

• Higher % shared code

• Second cmeters to viewlient takes less

time

• Working application can be developed

by any .NET developer; no mobile

development tools, licenses, hardware,

skills needed.

(mobile devs are more scarse and more

expensive than.NET devs)

• Consistent behaviour across platforms

easer

• Application logic simpler to understand

(read)

• Fully unit testable

• Can pass complex objects as para

Con Inverse of MVVM+ Pro’s Inverse of MVP+ Pro’s

Next Steps, Resources, QuestionsNext for MVVM+

• Optimize for less total LOC

• Possibly automation for repetitive development steps

(e.g. add a property)

• Possibly open source an example implementation.

Resources:

• http://stackoverflow.com/questions/2056/what-are-mvp-and-mvc-and-

what-is-the-difference

• http://propertycross.com/

• http://braincells2pixels.wordpress.com/2013/06/07/the-case-for-xamarin/

• http://vincenth.net

Questions?

[email protected]; for MVVM shared code questions: [email protected]

http://propertycross.com/

http://propertycross.com/

http://braincells2pixels.wordpress.com/2013/06/07/the-case-for-xamarin/

http://vincenth.net/

mailto:[email protected]

mailto:[email protected]

Skills reuse with xamarin and MVVM - Vincent for reusing dot NET skills... · Title: Skills reuse with xamarin and MVVM - Vincent Author: Mike Fortgens Subject: NLWeb Created Date:

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