The document provides an overview of how to get started developing Android applications. It discusses creating an Android project structure with Java code, XML layouts and resources. It also covers basic Android app components like activities, intents, views and lifecycle methods. The document then demonstrates how to work with lists, menus, context menus and storing data using SQLite and a database.

1. Android,
por onde começar ?

3. Android,
por onde comeCar ?
Mario Jorge Pereira

4. 2002
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2015

5. Desenvolvimento

6. Por onde começar?
http://developer.android.com

24. Run APP
Android application

26. manifests/
(AndroidManifest.xml)
java/
(código fonte: .java)
res/
(recursos: layouts,
strigs, icones …)

27. <RelativeLayout ...
android:layout_width=“match_parent”android:layout_height="match_parent" ...>
<TextView
android:text=“@string/hello_world"android:layout_width="wrap_content"android:layout_height="wrap_content" /></RelativeLayout>
activity_main.xml

28. <RelativeLayout ... >
<EditText
android:layout_width="match_parent"android:layout_height="30dp" />
<Button
android:layout_width="match_parent"android:layout_height="30dp" />
<TextView .../>
</RelativeLayout>
activity_main.xml

29. <LinearLayout ...
android:orientation="vertical" >
<EditText
android:layout_width="match_parent"android:layout_height="wrap_content" /><Button
android:text="@string/txtbotao"android:layout_width="match_parent"android:layout_height="wrap_content" /><TextView
android:layout_width="wrap_content"android:layout_height="wrap_content" /></LinearLayout>
activity_main.xml

30. <?xml version="1.0" encoding=“utf-8"?>
<resources>
<string name="app_name">Todo</string>
<string name="hello_world">Hello world!</string><string name="action_settings">Settings</string><string name=“txtbotao">Copiar</string></resources>
strings.xml

32. Activity
XMLpublic class OlaMundo extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_ola_mundo);
}
}

33. package br.com.mariojp.todo;
import android.os.Bundle;import android.support.v7.app.ActionBarActivity;public class MainActivity extends ActionBarActivity {@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);
}
...
}
MainActivity.java

34. /* AUTO-GENERATED FILE. DO NOT MODIFY.*/
public final class R {
public static final class attr {
}
public static final class dimen {
public static final int activity_horizontal_margin=0x7f040000;
public static final int activity_vertical_margin=0x7f040001;
}
public static final class layout {
public static final int activity_main=0x7f030000;
}
...
}
R.java

35. package br.com.mariojp.todo;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;import android.util.Log;
public class MainActivity extends ActionBarActivity {@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);
Log.i("Rotulo","Mensagem");
}
}
MainActivity.java

36. Log.[nivel](“TAG”,“MENSAGEM”);
Log.v (Verbose)
Log.d (Debug)
Log.i (Info)
Log.w (Warning)
Log.e (Erro)
Log.wtf (...)
Log

38. public class MainActivity extends Activity {
protected void onCreate(Bundle savedInstanceState) { ... }protected void onStart() { ... }
protected void onResume() { ... }
protected void onRestart() { ... }
protected void onPause() { ... }
protected void onStop() { ... }
protected void onDestroy() { ... }
}
MainActivity.java

39. Run As..
Android application

40. ...
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);
Button botao = (Button) findViewById(?);
}
...
MainActivity.java

41. <LinearLayout ... >
<EditText
android:id="@+id/campo"... />
<Button
android:id="@+id/botao"android:text="@string/txtbotao"android:layout_width="match_parent"android:layout_height="wrap_content" /><TextView
android:id=“@+id/rotulo"... />
</LinearLayout>
activity_main.xml

42. ...
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);
Button botao = (Button) findViewById(R.id.botao);}
...
MainActivity.java

43. ...
@Override
protected void onCreate(Bundle savedInstanceState) {
...
Button botao = (Button) findViewById(R.id.botao);
botao.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {Log.i("TODO","Clicou o Botao");}
});
}
...
MainActivity.java

44. ...
@Override
protected void onCreate(Bundle savedInstanceState) {
...
Button botao = (Button) findViewById(R.id.botao);
final EditText campo = (EditText) findViewById(R.id.campo);
final TextView rotulo = (TextView) findViewById(R.id.rotulo);
botao.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {rotulo.setText(campo.getText());}
});
}
...
MainActivity.java

45. Run As..
Android application

46. public class ListActivity extends ActionBarActivity {@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);setContentView(R.layout.?);
}
}
ListActivity.java

47. <LinearLayout ... >
<ListView
android:id="@+id/lista"android:layout_width="match_parent"android:layout_height="match_parent">
</ListView>
</LinearLayout>
activity_list.xml

48. ...
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);setContentView(R.layout.activity_list);
ListView lista = (ListView) findViewById(R.id.lista);
}
...
ListActivity.java

49. ...
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);setContentView(R.layout.activity_list);
ListView lista = (ListView) findViewById(R.id.lista);
String[] dados = new String[]{"IR A ERBASE”,"ESTUDAR PARA PROVA","COMPRAR CADERNO”};ArrayAdapter<String> adapter = new ArrayAdapter<String>
(this, android.R.layout.simple_list_item_1, dados);lista.setAdapter(adapter);
}
...
ListActivity.java

50. Run As..
Android application

51. <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="br.com.mariojp.todo" >
<application ... >
<activity android:name=“.MainActivity" android:label="Todo" >
</activity>
<activity android:name=".ListActivity" android:label="Todo" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
AndroidManifest.xml

52. Run As..
Android application

53. ...
lista.setOnItemClickListener(new AdapterView.OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> adapter, View view,
int position, long id){
Toast.makeText(ListActivity.this,"Posicao "+ position,Toast.LENGTH_SHORT).show();
}
});
...
ListActivity.java

54. Run As..
Android application

55. ...
lista.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> adapter, View view, int position,
long id) {
Toast.makeText(ListActivity.this,adapter.getItemAtPosition(position).toString(),
Toast.LENGTH_SHORT).show();return false;
}
});
...
ListActivity.java

56. Run As..
Android application

57. ...
lista.setOnItemClickListener(new AdapterView.OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> adapter, View view,
int position, long id){
Intent intent = new Intent(ListActivity.this,MainActivity.class);
startActivity(intent);
}
});
...
ListActivity.java

58. Run As..
Android application

59. <LinearLayout ...
android:orientation="vertical" >
<TextView
android:id=“@+id/rotulo”...
/>
<Button
android:id=“@+id/botao”...
/>
</LinearLayout>
activity_main.xml

60. ...
@Override
protected void onCreate(Bundle savedInstanceState) {
...
Button botao = (Button) findViewById(R.id.botao);
final TextView rotulo = (TextView) findViewById(R.id.rotulo);
botao.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {finish();
}
});
}
...
MainActivity.java

61. <?xml version="1.0" encoding=“utf-8"?>
<resources>
<string name="app_name">Todo</string>
<string name="hello_world">Hello world!</string><string name="action_settings">Settings</string><string name=“txtbotao">Voltar</string></resources>
strings.xml

62. ...
lista.setOnItemClickListener(new AdapterView.OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> adapter, View view,
int posicao, long id){
Intent intent = new Intent(ListActivity.this, MainActivity.class);
String valor = adapter.getItemAtPosition(posicao).toString();
intent.putExtra("tarefa", valor);startActivity(intent);}
});
...
ListActivity.java

63. ...
@Override
protected void onCreate(Bundle savedInstanceState) {
...
Button botao = (Button) findViewById(R.id.botao);
TextView rotulo = (TextView) findViewById(R.id.rotulo);Intent intent = getIntent();String valor = (String) intent.getSerializableExtra("tarefa");
rotulo.setText(valor);
botao.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {finish();
}
});
}
...
MainActivity.java

65. ...
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_list, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();if (id == R.id.action_settings) {return true;
}
return super.onOptionsItemSelected(item);
}
...
ListActivity.java

66. <menu
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context=".ListActivity" >
<item android:id="@+id/action_settings"
android:title="@string/action_settings"
android:orderInCategory="100"app:showAsAction="never" />
</menu>
menu_list.xml

67. <menu ...>
<item android:id="@+id/action_settings"
... />
<item android:id="@+id/action_nova"android:title="Nova"android:orderInCategory="100"app:showAsAction="always" />
</menu>
menu_list.xml

68. ...
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();switch (id){
case R.id.action_settings:Toast.makeText(this,"OPCOES",Toast.LENGTH_SHORT).show();
return true;
case R.id.action_nova:Toast.makeText(this,"NOVA",Toast.LENGTH_SHORT).show();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
...
ListActivity.java

69. <menu ...>
<item
android:id="@+id/editar"android:orderInCategory="100"android:title="Editar"/>
<item
android:id="@+id/excluir"android:orderInCategory="100"android:title="Excluir"/>
</menu>
context_menu.xml

70. ...
@Override
public void onCreateContextMenu(ContextMenu menu, View v,ContextMenu.ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
getMenuInflater().inflate(R.menu.context_menu, menu);}
...
ListActivity.java

71. ...
@Override
public boolean onContextItemSelected(MenuItem item) {
switch (item.getItemId()) {case R.id.editar:
Toast.makeText(this,"EDITAR",Toast.LENGTH_SHORT).show();
return true;
case R.id.excluir:
Toast.makeText(this,"EXLUIR",Toast.LENGTH_SHORT).show();
return true;
default:
return super.onContextItemSelected(item);
}
}
...
ListActivity.java

72. public class Tarefa {
private Long id;
private String titulo;
//get's e set's
}
Tarefa.java

73. <LinearLayout ...>
<TextView android:text="Tarefa"... />
<EditText
android:id="@+id/titulo"... />
<Button
android:id="@+id/botao"android:text="Salvar"android:onClick=“salvar"... />
</LinearLayout>
activity_cadastro.xml

74. ...
public void salvar(View view){Tarefa tarefa = new Tarefa();tarefa.setTitulo(titulo.getText().toString());
Toast.makeText(this,”Tarefa OK!",Toast.LENGTH_SHORT );
}
...
CadastroActivity.java

75. Run As..
Android application

76. Banco de dados

77. public class TarefaDAO extends SQLiteOpenHelper {private static final String DB_NAME = "tarefa.db";
private static final int DB_VERSION = 1;
public TarefaDAO(Context context) {super(context, DB_NAME, null, DB_VERSION);}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVer, int newVer) {
}
}
TarefaDAO.java

78. ...
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE TAREFAS (id INTEGER PRIMARY KEY,
titulo TEXT UNIQUE NOT NULL);");}
public void insere(Tarefa tarefa) {ContentValues valores = new ContentValues();
valores.put("titulo", tarefa.getTitulo());
getWritableDatabase().insert("TAREFAS", null, valores);
}
...
TarefaDAO.java

79. ...
public List<Tarefa> listar() {List<Tarefa> tarefas = new ArrayList<Tarefa>();
Cursor cursor = getReadableDatabase().query("TAREFAS", null, null,
null, null, null, null);while (cursor.moveToNext()) {Tarefa tarefa = new Tarefa();tarefa.setId(cursor.getLong(cursor.getColumnIndex("id")));
String titulo = cursor.getString(cursor.getColumnIndex(“titulo"));
tarefa.setTitulo(titulo);tarefas.add(tarefa);}
return tarefas;
}
...
TarefaDAO.java

80. ...
private ListView lista;...
@Override
protected void onCreate(Bundle savedInstanceState) {
lista = (ListView) findViewById(R.id.lista);
TarefaDAO dao = new TarefaDAO(this);List<Tarefa> dados = dao.listar();int layout = android.R.layout.simple_list_item_1;
ArrayAdapter<Tarefa> adapter =new ArrayAdapter<Tarefa>(this,layout, dados);
lista.setAdapter(adapter);
}
...
ListActivity.java

81. ...
private ListView lista;...
@Override
protected void onResume() {super.onResume()
lista = (ListView) findViewById(R.id.lista);
TarefaDAO dao = new TarefaDAO(this);List<Tarefa> dados = dao.listar();int layout = android.R.layout.simple_list_item_1;
ArrayAdapter<Tarefa> adapter =new ArrayAdapter<Tarefa>(this,layout, dados);
lista.setAdapter(adapter);}
...
ListActivity.java

82. public class Tarefa implements Serializable {
...
}
Tarefa.java

83. ...
lista.setOnItemClickListener(new AdapterView.OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> adapter, View view,
int posicao, long id){
Intent intent = new Intent(ListActivity.this, MainActivity.class);
Tarefa valor = (Tarefa) adapter.getItemAtPosition(posicao);
intent.putExtra("tarefa", valor);startActivity(intent);}
});
...
ListActivity.java

84. ...
@Override
protected void onCreate(Bundle savedInstanceState) {
...
Button botao = (Button) findViewById(R.id.botao);
TextView rotulo = (TextView) findViewById(R.id.rotulo);Intent intent = getIntent();Tarefa tarefa = (Tarefa) intent.getSerializableExtra("tarefa");
rotulo.setText(tarefa.getTitulo);
botao.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {finish();
}
});
}
...
MainActivity.java

85. ...
public void deletar(Tarefa tarefa) {String[] args = {tarefa.getId().toString()};
getWritableDatabase().delete("TAREFAS", "id=?", args);
}
...
TarefaDAO.java

86. ...
private Tarefa self = null;...
lista.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> adapter, View view, int position,
long id) {
sel = (Tarefa) adapter.getItemAtPosition(posicao);
return false;
}
});
...
ListActivity.java

87. ...
@Override
public boolean onContextItemSelected(MenuItem item) {
switch (item.getItemId()) {case R.id.editar:
Toast.makeText(this,"EDITAR",Toast.LENGTH_SHORT).show();
return true;
case R.id.excluir:
TarefaDAO dao = new TarefaDAO(this);
dao.deletar(tarefaSelecionada);return true;
default:
return super.onContextItemSelected(item);
}
}
...
ListActivity.java

88. ...
@Override
protected void carregaLista() {lista = (ListView) findViewById(R.id.lista);
TarefaDAO dao = new TarefaDAO(this);List<Tarefa> dados = dao.listar();int layout = android.R.layout.simple_list_item_1;
ArrayAdapter<Tarefa> adapter =new ArrayAdapter<Tarefa>(this,layout, dados);
lista.setAdapter(adapter);}
...
ListActivity.java

89. ...
@Override
protected void onResume() {super.onResume()
this.carregaLista();}
...
ListActivity.java

90. ...
@Override
public boolean onContextItemSelected(MenuItem item) {
switch (item.getItemId()) {case R.id.editar:
Toast.makeText(this,"EDITAR",Toast.LENGTH_SHORT).show();
return true;
case R.id.excluir:
TarefaDAO dao = new TarefaDAO(this);
dao.deletar(tarefaSelecionada);this.carregaLista();return true;
default:
return super.onContextItemSelected(item);
}
}
...
ListActivity.java

91. Esta obra está licenciada sob a licença Creative Commons
Atribuição-CompartilhaIgual 3.0 Não Adaptada. Para ver uma cópia
desta licença, visite http://creativecommons.org/licenses/by-sa/3.0/.

92. ANDROID
Mario Jorge Pereira
Como me encontrar?
http://www.mariojp.com.br
twitter.com/@mariojp
mariojp@gmail.com