public class Breakfast extends Activity implements OnItemClickListener {
DBOpener dbopener;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//for fullscreen view
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.dinner);
dbopener = new DBOpener(this);
}
// Open the DB, query all subject codes and refresh the listview when app resumes
@Override
protected void onResume() {
super.onResume();
// Configure the listview
ArrayList<String> mealNames = new ArrayList<String>();
ListView lstDine = (ListView)this.findViewById(R.id.dine);
lstDine.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, mealNames));
// Open/create the DB
try
{
dbopener.createDatabase(); // Create DB if necessary
dbopener.openDatabase(); // Open the DB
Cursor dinners = dbopener.getBreakfastNames();
while (dinners.moveToNext()) {
mealNames.add(dinners.getString(0)); // Get the Lunch Name & adds to list
}
dinners.close();
// Update the listview
ArrayAdapter<String> ad = (ArrayAdapter<String>)lstDine.getAdapter();
ad.notifyDataSetChanged();
lstDine.setOnItemClickListener(this);
}
catch (Exception e)
{
Toast.makeText(this, "Could not open DB", //Display when Database Cannot be opened
Toast.LENGTH_LONG).show();
}
}
//Close the DB when app pauses
@Override
protected void onPause() {
super.onPause();
dbopener.close();
}
// When user clicks on an item
public void onItemClick(AdapterView<?> parent, View v, int pos, long id) {
switch(pos)
{
case 0 :
Intent event1 = new Intent("com.edu.tp.iit.mns.Display");
//event1.putExtra("name" , ???);
//event1.putExtra("nutrition" , ???);
//event1.putExtra("rating" , ???);
startActivity(event1);
break;
这只是代码的一部分。我想知道我应该在（？？？）里面放什么。它是一个列表视图项..所以对于案例 0，我希望名称营养和评级显示在 Display 类中。这是我使用 SQLite 数据库浏览器完成的数据库。
public class DBOpener extends SQLiteOpenHelper {
private static String DB_PATH =
"/data/data/com.edu.tp.iit.mns/databases/"; //path of our database
private static String DB_NAME ="finals"; // Database name
private final Context myContext;
private SQLiteDatabase db;
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
public DBOpener(Context context) {
super(context, DB_NAME, null, 1);
myContext = context;
}
public void createDatabase() throws IOException {
boolean dbExists = checkDatabase();
if (dbExists) {
// Do nothing, DB already exists
Log.d("DBOpener", "DB exists");
} else {
// By calling this method an empty database will be created
// in the default system path of your application, which we
// will overwrite with our own database.
Log.d("DBOpener", "DB does not exit - copying from assets");
this.getReadableDatabase();
copyDatabase();
}
}
private boolean checkDatabase() {
SQLiteDatabase checkDB = null;
try {
// Try opening the database
String path = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(path, null,
SQLiteDatabase.OPEN_READONLY);
} catch (SQLiteException e) {
// If it fails, DB does not exist
}
if (checkDB != null)
checkDB.close(); // Close the DB; we don’t need it now
return checkDB != null;
}
private void copyDatabase() throws IOException {
InputStream istream = myContext.getAssets().open(DB_NAME);
OutputStream ostream = new FileOutputStream(DB_PATH + DB_NAME);
// Transfer bytes from istream to ostream
byte[] buffer = new byte[1024];
int length;
while ((length = istream.read(buffer)) > 0) {
ostream.write(buffer, 0, length);
}
// Close streams
istream.close();
ostream.flush();
ostream.close();
}
public void openDatabase() throws SQLiteException {
db = SQLiteDatabase.openDatabase(DB_PATH + DB_NAME, null,
SQLiteDatabase.OPEN_READWRITE);
}
@Override
public synchronized void close() {
if (db != null)
db.close();
super.close();
}
// Retrieve all subject codes
public Cursor getDinnerNames() {
if (db == null)
return null;
return db.query("dinner", new String[] {"name"},
null, null, null, null, null);
}
// Get details of specific subject
public Cursor getDinnerDetails(String name) {
if (db == null)
return null;
return db.query("dinner", new String[] {"name", "nutrition", "rating"},
"name = ?", new String[] {name}, null, null, null);
}
// Retrieve all subject codes
public Cursor getLunchNames() {
if (db == null)
return null;
return db.query("lunch", new String[] {"name"},
null, null, null, null, null);
}
// Get details of specific subject
public Cursor getLunchDetails(String name) {
if (db == null)
return null;
return db.query("dinner", new String[] {"name", "nutrition", "rating"},
"name = ?", new String[] {name}, null, null, null);
}
// Retrieve all subject codes
public Cursor getBreakfastNames() {
if (db == null)
return null;
return db.query("breakfast", new String[] {"name"},
null, null, null, null, null);
}
// Get details of specific subject
public Cursor getBreakfastDetails(String name) {
if (db == null)
return null;
return db.query("breakfast", new String[] {"name", "nutrition", "rating"},
"name = ?", new String[] {name}, null, null, null);
}
}
