Android101 : Introduksjon til Android

Android 101Introduksjon til AndroidTruls Jørgensenog Are Wold8. september 2010

BakgrunnAndroid kjøpesoppav Google i 2005 Googlesmotivasjon"Bedretjenesterogbrukeropplevelsepåmobilgirmermobilnettbrukogmerpengerireklamekassatil Google" (Computerworld UK)"Merinnovasjonpå mobile plattformer", "The world was broken"- Rich Miner, Google SidekickT-Mobile G1 / HTC DreamNexus One© 2010 Capgemini. All rights reserved.

Android!"The first truly open and comprehensive platform for mobile devices, all of the software to run a mobile phone but without the proprietary obstacles that have hindered mobile innovation"- Andy Rubin, Google © 2010 Capgemini. All rights reserved.

Utviklingsverktøy og dokumentasjonTilgjengeligeutviklingsplattformerEclipse, SDKEmulator, ADB, SQLiteDebugging på deviceDalvik debug monitor - tilstandpåenhetenLogCatOnline API reference, Java stylehttp://developer.android.com© 2010 Capgemini. All rights reserved.

..and now for somethingcompletelydifferent!

Fra XML til Java© 2010 Capgemini. All rights reserved.// res/layout/movie_list.xml<Button android:id="@+id/select_city_button“ android:textSize="20dp” />// R.java public static final class id { (…) public static final intselect_city_button=0x7f070016; }// MovieListActivity.java mCinemaButton = (Button) findViewById(R.id.select_city_button);

MovieList.xml<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical"android:layout_width="fill_parent"android:layout_height="fill_parent"android:background="#FFFFFF" (…) <Button android:id="@+id/movie_list_cinema" android:textSize="20dp"android:background="@drawable/select_city_button"android:text=“@string/select_city_text“ /></LinearLayout>Insert "Title, Author, Date"© 2010 Capgemini. All rights reserved.res/values/string.xml:(…)<stringname=”select_city_text">Velgby</string>

Activity – MovieListActivity.javapublicclassMovieListActivityextendsListActivity { (…)/** Called when the activity is first created. */@OverridepublicvoidonCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.movie_list);mMovieListHeader = (TextView) findViewById(R.id.movie_list_header);currentCity = getSelectedCity();mMovieListHeader.setText(getString(R.string.header_text_now_showing_in) + currentCity);updateMoviesForCity(currentCity); (…) }}Insert "Title, Author, Date"© 2010 Capgemini. All rights reserved.

KommunikasjonmellomkomponenterIntents kan:

Starte en Activity – spesifisert, eller ikke

Intents mellom activites© 2010 Capgemini. All rights reserved.// MovieListActivity.javafinal Intent intent = new Intent(this, MovieDetails.class);intent.putExtra(MoviesProvider._ID, id);startActivity(intent);// MovieDetailsActivity.javafinalIntentintent = getIntent();long id = intent.getExtras().getLong(MoviesProvider._ID);Insert "Title, Author, Date"

Intents mellom applikasjoner© 2010 Capgemini. All rights reserved.// MovieDetailsActivity.javafinal Intent intent = new Intent(Intent.ACTION_VIEW);intent.setData(Uri.parse(buyTicketLink));startActivity(intent);// MovieDetailsActivity.javafinal Intent intent= new Intent(Intent.ACTION_VIEW);intent.setDataAndType( Uri.parse(mMovieDetailsTrailerUrl),"video/*");startActivity(intent);

Content ProviderWrapper rundt en datakildeFor data somønskestilbudttilandreapplikasjoner (egentlig) Standardiserttilgangtil data vhaCONTENT_URI:content://no.jzinema.provider.Movies/movies© 2010 Capgemini. All rights reserved.

Content Provider: Persistering© 2010 Capgemini. All rights reserved.ContentProviderSqlite DB// Lagre en film// CONTENT_URI: content://no.jzinema.provider.Movies/moviesUriuri = mContext.getContentResolver().insert(MoviesProvider.CONTENT_URI, values);

Content Provider: Henting av data© 2010 Capgemini. All rights reserved.ContentProviderSqlite DB// MovieDetailsActiviy.java henter en film: //content://no.jzinema.provider.Movies/movies/5Cursor c = managedQuery(ContentUris.withAppendedId(MoviesProvider.CONTENT_URI, _id), null, null, null, null);// MovieListActivity.java spør // (blant annet) etter alle filmers idCursor c = managedQuery(MoviesProvider.CONTENT_URI, COLUMN_ID, null, null, null);

MoviesContentProvider.javapublicclassMoviesProviderextendsContentProvider { publicstaticfinal String AUTHORITY = "no.jzinema.provider.Movies";publicstaticfinal Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/movies");@OverridepublicbooleanonCreate(…)@Overridepublic Uri insert(…) @Override public Cursor query(…)@Override publicint update(…)@Override publicint delete(…) @Override public String getType(…)}Insert "Title, Author, Date"© 2010 Capgemini. All rights reserved.

MovieListActivity: Cursor og CursorAdapter© 2010 Capgemini. All rights reserved.// Alle filmer i en byCursor cursor = getContentResolver().query( MoviesProvider.CONTENT_URI, COLUMNS,MovieConstants.ATTRIBUTE_ID + " IN (" + movieIds + ")", null, null);startManagingCursor(cursor);// Opprett et cursorAdaptersombenyttercursorentil å populerehverradi listen mAdapter = newMovieListCursorAdapter (this, R.layout.movie_list_row, cursor, COLUMNS, VIEWS_IN_LIST_ROW);// ListActivitytrenger et adapter.this.setListAdapter(mAdapter);ContentProviderSqlite DB

KonfigureringAndroidManifest.xml<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"package="no.capgemini.jzinema” android:versionCode="1” android:versionName="1.0"><uses-permission android:name="android.permission.INTERNET" /><application android:icon="@drawable/icon" android:label="@string/app_name" android:debuggable="true">  <activity android:name=".MovieList“> <intent-filter><category android:name="android.intent.category.LAUNCHER" /><action android:name="no.capgemini.jzinema.SHOW_MOVIELIST" /></intent-filter></activity><providerandroid:authorities="no.jzinema.provider.Movies“android:name=".provider.MoviesProvider“ /> </application><uses-sdkandroid:minSdkVersion=“4" /></manifest>© 2010 Capgemini. All rights reserved.

AndroidManifest.xml - utdrag<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"package="no.capgemini.jzinema” android:versionCode="1” android:versionName="1.0"><uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /><application android:icon="@drawable/icon" android:label="@string/app_name"><activity android:name=".activity.movielist.MovieListActivity"android:label="@string/app_name"android:configChanges="orientation"><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter></activity><providerandroid:authorities="no.jzinema.provider.Movies“android:name=".provider.MoviesProvider“ /> </application><uses-sdkandroid:minSdkVersion=“4" /></manifest>Insert "Title, Author, Date"© 2010 Capgemini. All rights reserved.

Aktivitet starterForenkletlivssyklus for en ActivityonCreate()Bruker går tilbake til aktivitetenonStart()onRestart()onResume()Prosess dreptAktivitet kjørerAktivitet havner i forgrunnenAktivitet havner i bakgrunnenAktivitet havner i forgrunnenonSaveInstanceState()onPause()Lavt minneAktiviteten er usynligonStop()Aktivitet avsluttetLavt minne,finish()onDestroy()© 2010 Capgemini. All rights reserved.

Ytelse foran altBest practices i Java != Best practices i Android

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Android101 : Introduksjon til Android

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