Exemplo Adapters / Spinners

FACULDADE DE TECNOLOGIA SENAC PELOTAS
Curso Superior de Tecnologia em Análise e Desenvolvimento de Sistemas
Tópicos Avançados em ADS – Edécio Fernando Iepsen
============================== Exemplo Adapters / Spinners
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="br.com.edecio.spinnercidades.MainActivity">
<TextView
android:id="@+id/txtCidade"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/selecione_a_cidade" />
<Spinner
android:id="@+id/spnCidade"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/txtCidade"></Spinner>
</RelativeLayout>
package br.com.edecio.spinnercidades;
import
import
import
import
import
import
import
android.support.v7.app.AppCompatActivity;
android.os.Bundle;
android.view.View;
android.widget.AdapterView;
android.widget.ArrayAdapter;
android.widget.Spinner;
android.widget.Toast;
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
private ArrayAdapter<String> adpCidades;
private Spinner spnCidade;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
spnCidade = (Spinner) findViewById(R.id.spnCidade);
adpCidades = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item);
adpCidades.add("Pelotas");
adpCidades.add("Rio Grande");
adpCidades.add("Porto Alegre");
adpCidades.add("Caxias do Sul");
spnCidade.setAdapter(adpCidades);
adpCidades.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spnCidade.setOnItemSelectedListener(this);
}
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
String cidade = adpCidades.getItem(i);
Toast.makeText(this, "Cidade Selecionada: " + cidade, Toast.LENGTH_LONG).show();
}
@Override
public void onNothingSelected(AdapterView<?> adapterView) { }
}
============================== Exemplo Uso de Threads com AsyncTask
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:orientation="vertical"
tools:context="br.com.edecio.contagemregressiva.MainActivity">
<Button
android:id="@+id/btnContar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/iniciar_contagem"/>
<TextView
android:id="@+id/txtNumero"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:textSize="30sp"
android:textStyle="bold"
android:text="0"/>
</LinearLayout>
package br.com.edecio.contagemregressiva;
import
import
import
import
import
android.support.v7.app.AppCompatActivity;
android.os.Bundle;
android.view.View;
android.widget.Button;
android.widget.TextView;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private Button btnContar;
private TextView txtNum;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnContar = (Button) findViewById(R.id.btnContar);
txtNum = (TextView) findViewById(R.id.txtNumero);
btnContar.setOnClickListener(this);
}
@Override
public void onClick(View view) {
Conta task = new Conta(btnContar, txtNum);
task.execute(10);
}
}
package br.com.edecio.contagemregressiva;
import
import
import
import
android.os.AsyncTask;
android.os.SystemClock;
android.widget.Button;
android.widget.TextView;
public class Conta extends AsyncTask<Integer, Integer, Void> {
private Button btn;
private TextView txt;
public Conta(Button button, TextView textview) {
this.btn = button;
this.txt = textview;
}
@Override
protected void onPreExecute() {
btn.setEnabled(false);
}
@Override
protected void onPostExecute(Void aVoid) {
btn.setEnabled(true);
}
@Override
protected void onProgressUpdate(Integer... values) {
int n = values[0];
txt.setText(String.valueOf(n));
}
@Override
protected Void doInBackground(Integer... integers) {
int limite = integers[0];
for (int i=1; i<=limite; i++) {
SystemClock.sleep(500);
publishProgress(i);
}
return null;
}
}
============================== Exemplo Manipulação de Arquivos Texto na Memória Interna
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:orientation="vertical"
tools:context="br.com.edecio.listadecompras.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/informe_o_produto" />
<EditText
android:id="@+id/edtProduto"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<Button
android:id="@+id/btnAdiciona"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/adicionar_item"
android:onClick="Adiciona"/>
<Button
android:id="@+id/btnLista"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/listar_itens"
android:onClick="Lista"/>
<EditText
android:id="@+id/edtLista"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
package br.com.edecio.listadecompras;
import
import
import
import
import
import
android.support.v7.app.AppCompatActivity;
android.os.Bundle;
android.view.View;
android.widget.Button;
android.widget.EditText;
android.widget.Toast;
import
import
import
import
import
import
java.io.FileInputStream;
java.io.FileNotFoundException;
java.io.FileOutputStream;
java.io.IOException;
java.io.PrintWriter;
java.util.Scanner;
public class MainActivity extends AppCompatActivity {
private EditText edtProduto;
private EditText edtLista;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
edtProduto = (EditText) findViewById(R.id.edtProduto);
edtLista = (EditText) findViewById(R.id.edtLista);
}
public void Adiciona(View view) throws FileNotFoundException {
String produto = edtProduto.getText().toString();
try {
FileOutputStream fs = openFileOutput("compras.txt", MODE_APPEND);
PrintWriter pw = new PrintWriter(fs);
pw.println(produto);
pw.close();
Toast.makeText(this, "Ok! Produto Cadastrado", Toast.LENGTH_SHORT).show();
edtProduto.setText("");
edtProduto.requestFocus();
} catch (IOException e) {
Toast.makeText(this, "Erro..." + e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
public void Lista(View view) throws FileNotFoundException {
try {
FileInputStream fs = openFileInput("compras.txt");
Scanner entrada = new Scanner(fs);
StringBuilder linhas = new StringBuilder();
while (entrada.hasNextLine()) {
String linha = entrada.nextLine();
linhas.append(linha + System.lineSeparator());
}
edtLista.setText(linhas);
} catch (IOException e) {
Toast.makeText(this, "Erro..." + e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
}