在Android中，連接數據庫的方法通常是通過使用SQLite數據庫。以下是一種連接SQLite數據庫并在GridView中顯示數據的方法：
public class DatabaseHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "MyDatabase.db";
private static final int DATABASE_VERSION = 1;
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
// 創建表格的SQL語句
String createTableQuery = "CREATE TABLE IF NOT EXISTS MyTable (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT)";
db.execSQL(createTableQuery);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// 版本升級時的操作
}
}
public class MainActivity extends AppCompatActivity {
private GridView gridView;
private DatabaseHelper databaseHelper;
private SQLiteDatabase database;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gridView = findViewById(R.id.gridView);
// 初始化數據庫
databaseHelper = new DatabaseHelper(this);
database = databaseHelper.getReadableDatabase();
// 查詢數據
Cursor cursor = database.query("MyTable", null, null, null, null, null, null);
List<String> data = new ArrayList<>();
while (cursor.moveToNext()) {
String name = cursor.getString(cursor.getColumnIndex("name"));
data.add(name);
}
cursor.close();
// 使用適配器將數據顯示在GridView中
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, data);
gridView.setAdapter(adapter);
}
@Override
protected void onDestroy() {
super.onDestroy();
// 關閉數據庫連接
database.close();
databaseHelper.close();
}
}
上述代碼會在GridView中顯示數據庫表格"MyTable"中的"name"字段數據。您可以根據需要修改表名和字段名來適應您的數據庫結構。
