'

Building Your First Android App Using Xamarin

Понравилась презентация – покажи это...





Слайд 0


Слайд 1

Building your first Android app using Xamarin Gill Cleeren - @gillcleeren


Слайд 2

Building your first Android app using Xamarin Gill Cleeren @gillcleeren


Слайд 3

Hi, I’m Gill! Gill Cleeren MVP and Regional Director .NET Practice Manager @ Ordina Trainer & speaker @gillcleeren gill@snowball.be


Слайд 4

I’m a Pluralsight author! Courses on Windows 8, social and HTML5 http://gicl.me/mypscourses


Слайд 5

Agenda Overview of Xamarin and Xamarin.Android Xamarin.Android fundamentals Creating a detail screen Lists and navigation Navigating from master to detail (Optional) Intro to using Fragments Optimizing the application Preparing for store deployment


Слайд 6

Targets of this talk Understanding the fundamentals of Android app development with Xamarin See how a fully working app can be built


Слайд 7

The demo scenario Android Coffee Store Manager List of coffee Navigation to details page


Слайд 8

DEMO Looking at the finished application


Слайд 9

Overview of Xamarin and Xamarin.Android


Слайд 10

Hello Xamarin Xamarin enables developers to reach all major mobile platforms! Native User Interface Native Performance Shared Code Across Platforms C# & .NET Framework Toolset on top of Visual Studio Enables VS to create native iOS and Android apps Commercial product


Слайд 11

Advantages of Xamarin Full control Familiar development environment Native controls Native performance Code reuse Active component store


Слайд 12

Disadvantages of Xamarin You need a licence It’s not a shared UI Platform You need to understand each platforms UI controls and UX paradigms


Слайд 13

Write Everything in C# iOS, Android, Windows, Windows Phone, Mac Billions of Devices covered!


Слайд 14

The Xamarin platform Xamarin Xamarin.Android Xamarin.iOS Xamarin Forms


Слайд 15

Xamarin.Android exposes many extra device types


Слайд 16

Xamarin.Android Anything you can do in Java/Android can be done in C# and Visual Studio (or Xamarin Studio) with Xamarin!


Слайд 17

How Xamarin works on Android Mono VM + Java VM execute side-by-side (supports both Dalvik and ART) Mono VM JITs IL into native code and executes most of your code Can utilize native libraries directly as well as .NET BCL


Слайд 18

A word on code-sharing Xamarin brings development time through the use of code-sharing Possible (currently!) using Shared projects: allows organizing the shared code #if directives for platform specific code PCL “include” the platforms we want to support Abstract to interfaces where platforms have specific implementations


Слайд 19

Target architecture for a Xamarin app


Слайд 20

Preparing for Android development


Слайд 21

What you need for Xamarin.Android development Xamarin license (Xamarin.Android) PC or Mac Visual Studio or Xamarin Studio Android SDK and Emulators (installed via Xamarin setup) Emulator Device (not really required but...)


Слайд 22

Installing Xamarin.Android


Слайд 23

Visual Studio Integration A single solution: iOS Android Windows Phone Windows Store Leverage the entire Microsoft ecosystem: ReSharper Team Foundation Server Your favorite code coverage and profiling tools


Слайд 24

Visual Studio Integration Debug to: Emulators Devices Integrated into toolbar Status Logs List of devices


Слайд 25

Alternative: Xamarin Studio Optimized for cross-platform mobile development Explore native APIs with code completion World class Android and iOS designers Powerful debugging on simulator or device


Слайд 26

A word on emulators Setup will install some basic emulators for you They’re great… for drinking a lot of coffee


Слайд 27

Alternatives for the default emulators Possible options Genymotion -Requires VirtualBox under the hood HAXM drivers Android Player from Xamarin Microsoft Android emulator Hyper-V


Слайд 28

Developing with a device 3 steps Enable Debugging on the Device Install USB Drivers (Windows only) Connect the Device to the Computer


Слайд 29

Enable device debugging Tap the Build number 7 times to reveal developer options


Слайд 30

Install USB drivers


Слайд 31

Xamarin setup DEMO A quick look at the development setup


Слайд 32

Xamarin.Android fundamentals


Слайд 33

File ? New Project


Слайд 34

File ? New Project


Слайд 35

Fundamental #1: Activities Apps are collections of activities A view == an activity (for now ?) Apps don’t have an “entry point” No single code line which is called by the OS Apps start when Android creates one of the classes of the app App then gets loaded into memory


Слайд 36

Fundamental #1: Activities When opening an application, the OS creates the first Activity Activity is a specific class Defines UI and behaviour for a single task Corresponds to a single app screen App gets loaded in memory OS User launches app Activity Android loads app In memory


Слайд 37

Fundamental #1: Activities One activity needs to be the “entry point” for the app: MainLauncher=True


Слайд 38

Fundamental #1: Activities Often, the first activity is named MainActivity Is also a subclass of Activity and has the [Activity] attribute Makes sure that activity gets registered with the manifest to let Android know that the class is part of the application Label is the title of the screen Icon can be used to customize the displayed icon


Слайд 39

Activity lifecycle


Слайд 40

Activity lifecycle We can of course override these methods OnCreate: Create views, initialize variables, and do other prep work before the user sees the Activity This method is called only once when the Activity is loaded into memory OnResume Perform any tasks that need to happen every time the Activity returns to the device screen OnPause Perform any tasks that need to happen every time the Activity leaves the device screen


Слайд 41

Activity lifecycle in effect


Слайд 42

Fundamental #2: Views The layout of the app is contained in *.axml files AXML: Android designer file / Android XML First view of the app is named Main.axml Can be any name really AXML files live in the Resources/layout folder


Слайд 43

The designer for Xamarin.Android views


Слайд 44

The designer for Xamarin.Android views


Слайд 45

View code


Слайд 46

Connecting and accessing controls from code Linking a view with an activity is done using SetContentView


Слайд 47

Connecting and accessing controls from code We can name controls using the ID property The Android designer maps the control to the Resource class and assigns it a resource ID The code representation of a control is linked to the visual representation of the control in the designer via the Id property


Слайд 48

Connecting and accessing controls from code Once we have created the controls, we can access them from code Field name is used for lookup


Слайд 49

Fundamental #3: Application manifest An Android app contains a manifest file Contains a list of all resources, properties… that make up the application Also contains name, list of permissions… that the application has received Images Icons *.axml Others Android Manifest file


Слайд 50


Слайд 51

DEMO Creating our first Android application together!


Слайд 52

Navigation and lists


Слайд 53

Fundamental #4: ListViews and adapters Used very commonly in Android Common way to present lists of rows Each row is represented using a standard style or customized Consists out of ListView: visual part Adapter: feeds data to ListView


Слайд 54

Fundamental #4: ListViews and adapters


Слайд 55

Important classes ListView ListActivity BaseAdapter ArrayAdapter & ArrayAdapter<T>


Слайд 56

ListActivity and the built-in ArrayAdapter<T> [Activity(Label = "Coffees", MainLauncher = true, Icon = "@drawable/icon")] public class CoffeeScreenActivity: ListActivity { string[] coffees; protected override void OnCreate(Bundle bundle) { base.OnCreate(bundle); coffees= new string[] { "Coffee 1","Coffee 2", "Coffee 3"}; ListAdapter = new ArrayAdapter<String>( this, Android.Resource.Layout.SimpleListItem1, coffees); } }


Слайд 57

Implementing your own adapter In most cases, the ArrayAdapter won’t be enough We’ll need to create our own adapter Inherits from BaseAdapter Things we need to implement Count: To tell the control how many rows are in the data GetView: To return a View for each row, populated with data. This method has a parameter for the ListView to pass in an existing, unused row for re-use GetItemId: Return a row identifier (typically the row number, although it can be any long value that you like) this[int] indexer: To return the data associated with a particular row number


Слайд 58

Using row views Row views need to be re-used Certainly if we have a large number of rows As soon as a row disappears from screen, its view can be re-used When scrolling, the ListView calls GetView per row to display An unused row will be passed in via “View convertView” parameter If null, a new View needs to be created


Слайд 59

public class CoffeeAdapter : BaseAdapter<Coffee>  {         List<Coffee> items;         Activity context;         public CoffeeAdapter(Activity context, List<Coffee> items): base()         {             this.items = items;             this.context = context;         }         public override long GetItemId(int position)         {             return position;         }         public override Coffee this[int position]         {                get              {                  return items[position];              }          }         public override int Count          {             get              {                  return items.Count;              }          }         public override View GetView(int position, View convertView, ViewGroup parent)         {             var item = items[position];             if (convertView == null) {                 convertView = context.LayoutInflater.Inflate (Android.Resource.Layout.SimpleListItem1, null);             }             convertView.FindViewById<TextView> (Android.Resource.Id.Text1).Text = item.CoffeeName;             return convertView; } }


Слайд 60

Fast scrolling on the ListView Fast Scrolling helps the user to scroll through long lists by providing an additional ‘handle’ that acts as a scroll bar to directly access a part of the list Can be enabled by using ListView.FastScrollEnabled = true;


Слайд 61

Sectioning the ListView We need to implement on the adapter: GetSections: Provides the complete list of section index titles that could be displayed. This method requires an array of Java Objects so the code needs to create a Java.Lang.Object[] from a .NET collection. GetPositionForSection: Returns the first row position for a given section index GetSectionForPosition: Returns the section index to be displayed for a given row


Слайд 62

Handling row clicks To handle row clicks, we need to implement OnListItemClick protected override void OnListItemClick(ListView l, View v, int position, long id) { var t = items[position]; //do something }


Слайд 63

DEMO Adding a ListView and an adapter


Слайд 64

Customizing the ListView with other row views


Слайд 65

Customizing the ListView with other row views


Слайд 66

Customizing the ListView with other row views


Слайд 67

DEMO Using the built-in row views


Слайд 68

Creating your own row views Custom row layouts are AXML files in Resources/layout Are loaded by Id using a custom adapter View can contain any number of display classes with custom colors, fonts…


Слайд 69

Creating your own row view <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:padding="8dp"     android:orientation="horizontal">     <ImageView         android:id="@+id/CoffeeImageView"         android:layout_width="50dp"         android:layout_height="50dp"         android:padding="5dp" />     <LinearLayout         android:id="@+id/TextFields"         android:orientation="vertical"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:paddingLeft="10dip">         <TextView             android:id="@+id/CoffeeNameText"             android:layout_width="wrap_content"             android:layout_height="wrap_content" />         <TextView             android:id="@+id/PriceText"             android:layout_width="wrap_content"             android:layout_height="wrap_content" />     </LinearLayout> </LinearLayout>


Слайд 70

Using your custom row view public override View GetView(int position, View convertView, ViewGroup parent) {     //custom view  var item = items[position];  if (convertView == null)  {       convertView = context.LayoutInflater.Inflate (Resource.Layout.CoffeeRowView, null);     }              convertView.FindViewById<ImageView>  (Resource.Id.CoffeeImageView).SetImageResource( imageRepository.ImageNameToResourceInt(item.ImageId.ToString())); convertView.FindViewById<TextView>  (Resource.Id.CoffeeNameText).Text = item.CoffeeName;     convertView.FindViewById<TextView>  (Resource.Id.PriceText).Text = item.Price.ToString();     return convertView; }


Слайд 71

DEMO Adding our own custom row view


Слайд 72

Fundamental #5: Intents An Intent is an abstract concept for some sort of operation that should be performed in Android Navigating to another activity Often, launching an external application (= built-in) with the intent of doing something Make a phone call Launch a URI Map an address An intent often consist out of What the intent is The data needed for the intent Phone number to call


Слайд 73

Intent of making a phone call ActionCall asks Android for an Activity to make a phone call


Слайд 74

Intent of navigating to another screen StartActivity can be used to start another activity PutExtra() is used to pass data from one activity to the other var intent = new Intent (); intent.SetClass (this, typeof(CoffeeDetailActivity)); intent.PutExtra ("selectedCoffeeId", t.CoffeeId); StartActivity (intent);


Слайд 75

Receiving information from the intent protected override void OnCreate (Bundle bundle) {     base.OnCreate (bundle);     SetContentView (Resource.Layout.Main);     var selectedCoffeeId = Intent.Extras.GetInt ("selectedCoffeeId", 0);     Coffee coffee = DataService.GetCoffeeById (selectedCoffeeId); }


Слайд 76

DEMO Navigating from the List to the Detail page


Слайд 77

Adding Fragments


Слайд 78

The need for Fragments Larger screen: more complex to build UIs that look good on all screens Layouts which look good on a small screen may not look good on a large tablet screen Android V3.0 introduced Fragments Fragment is a UI module UI gets divided into reusable parts Each “part” is an separate activity At run time, the Activities themselves will decide which Fragments to use Also work in older versions through Support packages


Слайд 79

The need for Fragments


Слайд 80

FragmentManager To help an Activity coordinate and manage all these Fragments, Android introduced a new class called the FragmentManager Each activity has an instance of the FragmentManager Allows finding, adding and removing fragments


Слайд 81

Creating a fragment A Fragment inherits from Android.App.Fragment Must override the OnCreateView OnCreateView is called by the hosting activity when the Fragment is placed on the screen Returns a View OnCreateView will create the View (of the fragment) by inflating a layout file and attaching that to the parent container Will apply the same parameters as the parent container public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { return inflater.Inflate(Resource.Layout.CoffeeFragment, container, false); }


Слайд 82

Adding a fragment to an Activity We can add the Fragment to the Activity in 2 ways Declaratively: Fragments can be used declaratively within .axml layout files by using the <Fragment> tag Programmatically Fragments can also be instantiated dynamically by using the FragmentManager class’s API


Слайд 83

DEMO Refactoring to Fragments


Слайд 84

Optimizing the application


Слайд 85

Managing strings in strings.xml We can have Android store string values for us <?xml version="1.0" encoding="utf-8"?> <resources>     <string name="hello">Hello World, Click Me!</string>     <string name="app_name">AndroidCoffeeStore</string>     <string name="coffeeNameLabel">Coffee name</string> </resources> <TextView     android:text="@string/coffeeNameLabel"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:id="@+id/CoffeeNameLabel" />


Слайд 86

Making the app multi-language


Слайд 87

Application drawables We can add drawables: application icons Adding all resolutions makes sure the icons look good on all screens Filenames are the same Folder name identifies the resolution


Слайд 88

Application drawables We can select an image in the project properties This now becomes the icon for the application within Android


Слайд 89

DEMO Adding resources and drawables to the application


Слайд 90

Deploying to the store


Слайд 91

Publishing your work Marketplace is most common option Often, more than one is used (Google Play, Amazon, GetJar…) Email or website is often for a more closed distribution Also require less work to prepare the application for distribution Google Play is best known store Allows users to discover, download, rate, and pay for applications by clicking a single icon either on their device or on their computer Google Play also provides tools to assist in the analysis of sales and market trends and to control which devices and users may download an application


Слайд 92

Summary Xamarin.Android leverages your C# knowledge to build apps for Android Concepts of Android mean a learning curve


Слайд 93

Thanks!


Слайд 94

Q&A


Слайд 95

Building your first Android app using Xamarin Gill Cleeren - @gillcleeren


Слайд 96

Your feedback is important! Scan the QR Code and let us know via the TechDays App. Laat ons weten wat u van de sessie vindt via de TechDays App! Scan de QR Code. Bent u al lid van de Microsoft Virtual Academy?! Op MVA kunt u altijd iets nieuws leren over de laatste technologie van Microsoft. Meld u vandaag aan op de MVA Stand. MVA biedt 7/24 gratis online training on-demand voor IT-Professionals en Ontwikkelaars.


Слайд 97

Building your first Android app using Xamarin Gill Cleeren @gillcleeren


×

HTML:





Ссылка: