我有一个简单的数据库，其中包含三星型号和价格。
public class DBHelper extends SQLiteOpenHelper implements BaseColumns {
public static final String TABLE_NAME = "samsung";
public static final String NAME = "model";
public static final String MODEL_PRICE = "price";
public DBHelper(Context context) {
super(context, PhoneProvider.DB_CONTACTS, null, 6);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE " + TABLE_NAME
+ " (_id INTEGER PRIMARY KEY AUTOINCREMENT, " + NAME
+ " TEXT, " + MODEL_PRICE + " TEXT);");
ContentValues values = new ContentValues();
values.put(NAME, "Galaxy S4 Active");
values.put(MODEL_PRICE, "680");
db.insert(TABLE_NAME, NAME, values);
values.put(NAME, "Galaxy S4");
values.put(MODEL_PRICE, "659");
db.insert(TABLE_NAME, NAME, values);
values.put(NAME, "Galaxy Note II");
values.put(MODEL_PRICE, "627");
db.insert(TABLE_NAME, NAME, values);
values.put(NAME, "Galaxy Mega 6.3");
values.put(MODEL_PRICE, "581");
db.insert(TABLE_NAME, NAME, values);
values.put(NAME, "Galaxy S4 Zoom");
values.put(MODEL_PRICE, "575");
db.insert(TABLE_NAME, NAME, values);
values.put(NAME, "Galaxy SIII");
values.put(MODEL_PRICE, "523");
db.insert(TABLE_NAME, NAME, values);
values.put(NAME, "Galaxy S4 Mini Duos");
values.put(MODEL_PRICE, "500");
db.insert(TABLE_NAME, NAME, values);
values.put(NAME, "Galaxy Mega 5.8");
values.put(MODEL_PRICE, "418");
db.insert(TABLE_NAME, NAME, values);
values.put(NAME, "Galaxy Grand Duos");
values.put(MODEL_PRICE, "366");
db.insert(TABLE_NAME, NAME, values);
values.put(NAME, "Galaxy SII Plus");
values.put(MODEL_PRICE, "349");
db.insert(TABLE_NAME, NAME, values);
values.put(NAME, "Galaxy SIII Mini");
values.put(MODEL_PRICE, "314");
db.insert(TABLE_NAME, NAME, values);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
} }
数据库使用 ContentProvider
public class PhoneProvider extends ContentProvider {
public static final String DB_CONTACTS = "phones.db";
public static final Uri CONTENT_URI = Uri.parse(
"content://com.example.newtransaction.phoneprovider/phone");
public static final int URI_CODE = 1;
public static final int URI_CODE_ID = 2;
private static final UriMatcher mUriMatcher;
private static HashMap<String, String> mContactMap;
private SQLiteDatabase db;
static {
mUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
mUriMatcher.addURI("com.example.newtransaction.phoneprovider",
DBHelper.TABLE_NAME, URI_CODE);
mUriMatcher.addURI("com.example.newtransaction.phoneprovider",
DBHelper.TABLE_NAME + "/#", URI_CODE_ID);
mContactMap = new HashMap<String, String>();
mContactMap.put(DBHelper._ID, DBHelper._ID);
mContactMap.put(DBHelper.NAME, DBHelper.NAME);
mContactMap.put(DBHelper.MODEL_PRICE, DBHelper.MODEL_PRICE);
}
public String getDbName() {
return(DB_CONTACTS);
}
@Override
public boolean onCreate() {
db = (new DBHelper(getContext())).getWritableDatabase();
return (db == null) ? false : true;
}
@Override
public Cursor query(Uri url, String[] projection,
String selection, String[] selectionArgs, String sort) {
String orderBy;
if (TextUtils.isEmpty(sort)) {
orderBy = DBHelper.NAME;
}
else {
orderBy = sort;
}
Cursor c = db.query(DBHelper.TABLE_NAME, projection, selection, selectionArgs,
null, null, orderBy);
c.setNotificationUri(getContext().getContentResolver(), url);
return c;
}
@Override
public Uri insert(Uri url, ContentValues inValues) {
ContentValues values = new ContentValues(inValues);
long rowId = db.insert(DBHelper.TABLE_NAME, DBHelper.NAME, values);
if (rowId > 0) {
Uri uri = ContentUris.withAppendedId(CONTENT_URI, rowId);
getContext().getContentResolver().notifyChange(uri, null);
return uri;
}
else {
throw new SQLException("Failed to insert row into " + url);
}
}
@Override
public int delete(Uri url, String where, String[] whereArgs) {
int retVal = db.delete(DBHelper.TABLE_NAME, where, whereArgs);
getContext().getContentResolver().notifyChange(url, null);
return retVal;
}
@Override
public int update(Uri url, ContentValues values,
String where, String[] whereArgs) {
int retVal = db.update(DBHelper.TABLE_NAME, values, where, whereArgs);
getContext().getContentResolver().notifyChange(url, null);
return retVal;
}
@Override
public String getType(Uri uri) {
return null;
} }
我需要在片段上添加这个数据库，通过按 RadioButton 显示
public class MainActivity extends FragmentActivity {
FragmentTransaction ft;
Fragment1 frg1;
Fragment2 frg2;
Fragment3 frg3;
Fragment4 frg4;
Fragment5 frg5;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// dbhelper = new DBHelper(this);
frg1 = new Fragment1();
frg2 = new Fragment2();
frg3 = new Fragment3();
frg4 = new Fragment4();
frg5 = new Fragment5();
RadioButton btn1 = (RadioButton) findViewById(R.id.radio1);
btn1.setChecked(true);
getSupportFragmentManager().beginTransaction().add(R.id.frame, frg1)
.commit();
// set listener
((RadioGroup) findViewById(R.id.radio_group))
.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
ft = getSupportFragmentManager().beginTransaction();
switch (checkedId) {
case R.id.radio1:
ft.replace(R.id.frame, frg1);
break;
case R.id.radio2:
ft.replace(R.id.frame, frg2);
break;
case R.id.radio3:
ft.replace(R.id.frame, frg3);
break;
case R.id.radio4:
ft.replace(R.id.frame, frg4);
break;
case R.id.radio5:
ft.replace(R.id.frame, frg5);
break;
}
ft.commit();
}
});
}}
片段之一的代码
public class Fragment2 extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
container.removeAllViews();
return inflater.inflate(R.layout.fragment2, null);
} }
它基于 Goloshchapov - Google Android 一书中的一个示例。移动编程 我是 Android 新手。