How to connect a database in Android GridView?

To connect a database in Android GridView, you can follow these steps:

1. The document named build.gradle.

implementation 'androidx.room:room-runtime:2.2.6'
annotationProcessor 'androidx.room:room-compiler:2.2.6'

1. This is an entity.

@Entity(tableName = "items")
public class Item {
    @PrimaryKey
    public int id;
    public String name;
}

1. @Martial Arts practitionere

@Dao
public interface ItemDao {
    @Query("SELECT * FROM items")
    List<Item> getAllItems();

    // 其他数据库操作方法...
}

1. Database specifically designed for use within a single room or space.
2. The database

@Database(entities = {Item.class}, version = 1)
public abstract class AppDatabase extends RoomDatabase {
    public abstract ItemDao getItemDao();

    private static AppDatabase instance;

    public static synchronized AppDatabase getInstance(Context context) {
        if (instance == null) {
            instance = Room.databaseBuilder(context.getApplicationContext(),
                    AppDatabase.class, "app_database")
                    .allowMainThreadQueries()
                    .build();
        }
        return instance;
    }
}

1. Initialize and use the database in your Activity or Fragment class using the following code:

AppDatabase db = AppDatabase.getInstance(getApplicationContext());
ItemDao itemDao = db.getItemDao();

// 查询所有数据
List<Item> items = itemDao.getAllItems();

// 将查询结果传递给 GridView 的适配器进行显示
GridView gridView = findViewById(R.id.gridView);
GridAdapter gridAdapter = new GridAdapter(items);
gridView.setAdapter(gridAdapter);

// 其他数据库操作...

In this way, you can connect to a database and display data in an Android GridView. Please note that the code above is just an example, and if your project is using a different database framework (such as SQLite), you will need to modify the code accordingly.