Transcript
Creare app native su iOS, Android, Mac & Windows in C#
Introduzione a Xamarin.iOS
Gli speaker di oggi
Guido MagrinXamarin & Microsoft Student Partner
Xamarin Certified Developer
@GuidoMagrin
Dove trovo le slide?
http://www.slideshare.net/guidomagrin
Gli Xamarin Student Partner
https://www.facebook.com/XSAMilano
Oggi parleremo di…
Xamarin.iOS
Chi ha giàsentito parlare diXamarin.iOS?
Xamarin + Xamarin.FormsApproccio offerto da Xamarin.Forms: Codice UI condiviso, controlli nativi
Approccio tradizionale di Xamarin
Shared UI Code
.NET + iOS APIs | copertura al 100%
Qualsiasi cosa si possa fare in Objective-Co Swift può essere fatta in C#con Xamarin in Visual Studio
Xamarin è sempre aggiornato
Release iOS supportate al day-one:iOS 5, iOS 6, iOS 7, iOS 7.1, iOS 8, iOS 9, iOS 10
Supporto ad Apple Watch!
Xamarin StudioPC o Mac
Plugin Visual Studio VS 2010 e
superiore
Ambienti di Sviluppo
Integrazione in Visual Studio
Una soluzione sola per:• iOS• Android• Windows Phone• Windows Store
Tutti i plugin e le funzioni di Visual Studio:• ReSharper• Team Foundation Server
Integrazione in Visual Studio
Debugging su:• Emulatori• Dispositivi
Integrati nella toolbar:• Stato• Logs• Lista di dispositivi
Xamarin Studio
• Ottimizzato per lo sviluppo cross-platform
• Accedi alle API native con l’autocompletamento
• Designer per Android e iOS
• Debugging avanzato su emulatore o dispositivo
Designer per Xamarin iOS
• Il primo designer iOS presente in Xamarin Studio e Visual Studio
• Simile al designer tradizionale di Visual Studio
• Supporta pienamente l’UIKit
• Modifica i componenti personalizzati e di terze parti
• Modifiche grafiche applicate in tempo reale
Cosa impareremo oggi?
• Fundamentals• The package• Views and navigation• Managing lists• Working files
Fundamentals
Before we start...
• You need a Mac:– OS X 10.9.4+– Xcode– Xamarin.iOS
• You can still work on your Windows PC:– Visual Studio– Xamarin.iOS
Before we start...
• The OS X and Windows machines have to be connected to the same network
• You can connect a OS X machine only to multiple Windows machines
• OS X and Windows need to have the same Xamarin.iOS version installed
iPhone simulator
• Requires the latest version of Xamarin.iOS.
• Allows you to “completely forget” about your Mac.
• Fun fact: given that the Windows PC has a touchscreen, it supports this kind of input.
What if I don’t have a Mac? Rent one!
• Always available.• Pay as you go.• Scalable according to our needs.
The application
• Main– It’s the entry point of the app– It creates the application
• AppDelegate– It manages the system events– It has an Application Window with the UI– It starts the Main interface
The startup
• Storyboard– Takes care of initializing the main controller– The controller manages the main view and the sub views
• ViewController– It receives the interactions
from the views– It takes care of displaying
the data on the view
Apple Watch has Storyboards, too!
• Same functionalities you would expect from iPhone storyboards.
• As of today, easier to work with in terms of app rescaling.
Model-View-Controller (MVC)
• iOS is based on MVC– The Model describes the data– The View describes the UI– The Controller manages the interactions
between the Model and the View
La prima appXamarin.Forms
Domanda 1
Posso creare applicazioni iOS usando esclusivamente un PC Windows
a) Verob) Falso
Domanda 1
Posso creare applicazioni iOS usando esclusivamente un PC Windows
a) Verob) Falso
Domanda 2
Da quali componenti è composta un’applicazione iOS?a) Main, AppDelegateb) Window, AppDelegatec) Main, ViewControllerd) Screen, ViewController
Domanda 2
Da quali componenti è composta un’applicazione iOS?a) Main, AppDelegateb) Window, AppDelegatec) Main, ViewControllerd) Screen, ViewController
The package
Resources
• iOS requires that all the resources are placed in the root folder
• Xamarin adds a Resource folder– At compile time, the content is copied in the root
• The Build Action has to be set to BundleResource
Images
• The original iPhone had a resolution of 320x480
• New resolutions have been added• Naming conventions to manage the assets:
– @2x -> Retina– @3x-> iPhone 6 Plus– ~iphone -> Used on the iPhone– ~ipad -> Used on the iPad– Example: Image.png, Image@2x.png,
Image2x~iphone.png
Info.plist and Entitlements.plist
iPhone Deployment info• It contains the main info about the app
configuration:– Main interface– Supported orientations– Status bar style
Entitlements• Used to configure iCloud,
push notifications, HealthKit, etc.
Views andnavigation
La prima appXamarin.Forms
Domanda 1
Se volessi implementare iCloud nella mia app iOS, tramite quale file dovrei abilitarne l’integrazione?
a) BundleResources.plistb) Info.plistc) CloudConnectivity.plistd) Entitlements.plist
Domanda 1
Se volessi implementare iCloud nella mia app iOS, tramite quale file dovrei abilitarne l’integrazione?
a) BundleResources.plistb) Info.plistc) CloudConnectivity.plistd) Entitlements.plist
Storyboards
• In the past, iOS developers managed views using the XIB files
• Each XIB files was mapped with a controller• The developer needed to manually manage the
navigation between two views
Storyboards
• A storyboard is the visual representation of all the screens in an app
• It’s made by different scenes• A scene is a View managed by a
ViewController• Scenes contains objects and controls that are
used to manage interactions and to display data
The Xamarin designer
• Storyboards can’t be created in code• The underline XML is generated
automatically by the designer• Xamarin offers a built-in designer, which
requires a Mac Build Host connected to the Windows machine
Navigation
• Navigation in Storyboards is managed using Segues
• A Segue is a transition between two scenes• Multiple transitions:
– Simple navigation– Modal views– Popover
• Segues are created using the designer
Storyboards, Segues and Xamarin designer
Storyboards and segues
DEMO
La prima appXamarin.Forms
Domanda 1
Come si chiama il file contenente tutte le schermate della mia app iOS?
a) Seguesb) Storyboardc) Designerd) BuildHost
Domanda 1
Come si chiama il file contenente tutte le schermate della mia app iOS?
a) Seguesb) Storyboardc) Designerd) BuildHost
Domanda 2
Cosa uso per navigare tra le varie pagine della mia app iOS?a) Navigatorb) Arrowc) Transitionerd) Segues
Domanda 2
Cosa uso per navigare tra le varie pagine della mia app iOS?a) Navigatorb) Arrowc) Transitionerd) Segues
Passing data
• A storyboards offers a method called PrepareForSegue() to override
• You get a reference to the destination control and you pass the data into a property
public override void PrepareForSegue(UIStoryboardSegue segue, NSObject sender){
base.PrepareForSegue(segue, sender);var controller = segue.DestinationViewController as MyPageController;controller.TextToShow = MyPhoneNumber.Text;
}
Conditional navigation
• Sometimes you need to perform navigation only if a specific condition is satisfied
• You can override the ShouldPerformSegue() method
public override bool ShouldPerformSegue(string segueIdentifier, NSObject sender){
if (segueIdentifier == "SegueToMainPage") { if (PasswordTextField.Text == "password") return true; else return false; } return base.ShouldPerformSegue(segueIdentifier, sender);}
Advanced segues
DEMO
The view’s lifecycle
Methods intherited by the UIViewController class• ViewDidLoad
– The controller has loaded the connected view• ViewWillAppear
– The pagecontent is about to appear• ViewWillDisappear
– The page content is about to disappear• ViewDidAppear / ViewDidDisappear
– The page content is appeared / disappeared
Alerts
If you target a pre iOS 8 device, you need to use the UIAlertView class
UIAlertView av = new UIAlertView("Title", "message", null, "OK", null);av.Show();
Alerts
If you target an iOS 8+ device, you can use:• UIAlertController to display an alert• UIActionSheet to display an action sheet
UIAlertController UIActionSheet
Alerts
DEMO
Built-in applications
• Same URI-based approach that you find in Windows Phone
• You use the OpenUrl() method to invoke a URL
NSUrl url = new NSUrl("http://www.xamarin.com");
if (UIApplication.SharedApplication.CanOpenUrl(url)){
UIApplication.SharedApplication.OpenUrl(url);}
Managing lists
Table Views
Many different classes and APIs to implement a list• UITableView
– It’s the table that contains the rows to display• UITableViewCell
– It represent a row of the list• UITableViewSource
– It’s a specific Xamarin class that makes easier to implement a UITableView
– On iOS, you would to implement separately the UIViewTableDataSource and UITableViewDelegate classes
Table Views
Many different classes and APIs to implement a list• NSIndexPath
– It identifies a specific element of the table• UITableViewController
– It’s the controller that implements an UITableView
Table layout
• Four different built-in styles• To implement a custom layout, you need to
implement a custom cell
Creating a UITableViewSource• You need to choose a cell identifier• You need to implement the GetCell() method to
define the layout of a cell public class TableSource : UITableViewSource { string[] tableItems; string cellIdentifier = "TableCell"; public TableSource(string[] items) { tableItems = items; } public override nint RowsInSection(UITableView tableview, nint section) { } public override UITableViewCell GetCell(UITableView tableView, Foundation.NSIndexPath indexPath) {
... }}
Cell reuse
• It’s the technique used to improve performances in case of big collections to display
• You first ask for a cell to reuse before creating a new one
public override UITableViewCell GetCell(UITableView tableView, Foundation.NSIndexPath indexPath){ UITableViewCell cell = tableView.DequeueReusableCell(cellIdentifier); // if there are no cells to reuse, create a new one if (cell == null) cell = new UITableViewCell(UITableViewCellStyle.Default, cellIdentifier); cell.TextLabel.Text = tableItems[indexPath.Row]; return cell;}
Cell reuse
Starting from iO6, there’s a new method that automatically takes care of generating the proper cell for youpublic override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath){ var cell = (MyCell)tableView.DequeueReusableCell(MyCellId, indexPath);
return cell;}
Additional supported features
Managinglists
DEMO
La prima appXamarin.Forms
Domanda 1
Di quali metodi e controlli mi posso avvalere per creare una lista in un’app iOS?
a) UITableViewb) UITableViewContainerc) UITableViewSourced) UITableViewCell
Domanda 1
Di quali metodi e controlli mi posso avvalere per creare una lista in un’app iOS?
a) UITableViewb) UITableViewContainerc) UITableViewSourced) UITableViewCell
Domanda 2
Per implementare un Custom Layout, devo implementare una Custom Cell
a) Verob) Falso
Domanda 2
Per implementare un Custom Layout, devo implementare una Custom Cell
a) Verob) Falso
Domanda 3
Quante tipologie di Layout di default sono presenti?a) Dueb) Quattroc) Ottod) Dodici
Domanda 3
Quante tipologie di Layout di default sono presenti?a) Dueb) Quattroc) Ottod) Dodici
Using a custom layout
• You need to create a custom cell• You can do it in code or with the designer• You add the controls inside
the UIViewTableCell object• In code, you assign a value to the controls
Using a custom layout
In the UITableViewSource, you use the custom cell class instead of the base UITableViewCell one in the GetCell() methodpublic override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath){ CharacterCellView cell = tableView.DequeueReusableCell(CellIdentifier, indexPath) as CharacterCellView; Character currentCharacter = tableItems[indexPath.Row]; cell.UpdateCharacter(currentCharacter);
return cell;}
Custom cells
DEMO
Working with files
Files and folders
• To create files and folder you can leverage the basic .NET APIs (System.IO)
• Documents is the base path where all the files of the application are stored
• In the info.plist you can set the option UIFileSharingEnabled to true to allow access to local files through iTunes
The folders
• Library– To store the internal files of the application– It’s automatically backed up
• Library/Preferences– To store the application settings– It’s automatically backed up
• Library/Caches– iOS can delete the content in case the space is going low– It’s not backed up
Working withfiles and folders
DEMO
Grazie per l’attenzione
Guido MagrinXamarin Student Partner
@GuidoMagrin
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