要实现从两个RecyclerView向数据库发送请求,并在第三个RecyclerView中接收数据,您可以按照以下步骤进行操作:
public class DatabaseHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "your_database_name";
private static final int DATABASE_VERSION = 1;
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
// 创建数据库表
String createTableQuery = "CREATE TABLE your_table_name (id INTEGER PRIMARY KEY, data TEXT)";
db.execSQL(createTableQuery);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// 数据库升级逻辑
}
// 向数据库插入数据
public void insertData(String data) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("data", data);
db.insert("your_table_name", null, values);
db.close();
}
// 从数据库查询数据
public List getData() {
List dataList = new ArrayList<>();
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery("SELECT * FROM your_table_name", null);
if (cursor.moveToFirst()) {
do {
String data = cursor.getString(cursor.getColumnIndex("data"));
dataList.add(data);
} while (cursor.moveToNext());
}
cursor.close();
db.close();
return dataList;
}
}
public class RecyclerViewAdapter extends RecyclerView.Adapter {
List dataList;
public RecyclerViewAdapter(List dataList) {
this.dataList = dataList;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_layout, parent, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
String data = dataList.get(position);
holder.textView.setText(data);
}
@Override
public int getItemCount() {
return dataList.size();
}
public static class ViewHolder extends RecyclerView.ViewHolder {
TextView textView;
public ViewHolder(@NonNull View itemView) {
super(itemView);
textView = itemView.findViewById(R.id.textView);
}
}
}
public class MainActivity extends AppCompatActivity {
RecyclerView recyclerView1, recyclerView2, recyclerView3;
RecyclerViewAdapter adapter1, adapter2, adapter3;
List data1, data2, data3;
DatabaseHelper databaseHelper;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView1 = findViewById(R.id.recyclerView1);
recyclerView2 = findViewById(R.id.recyclerView2);
recyclerView3 = findViewById(R.id.recyclerView3);
data1 = new ArrayList<>();
data2 = new ArrayList<>();
data3 = new ArrayList<>();
adapter1 = new RecyclerViewAdapter(data1);
adapter2 = new RecyclerViewAdapter(data2);
adapter3 = new RecyclerViewAdapter(data3);
recyclerView1.setLayoutManager(new LinearLayoutManager(this));
recyclerView1.setAdapter(adapter1);
recyclerView2.setLayoutManager(new LinearLayoutManager(this));
recyclerView2.setAdapter(adapter2);
recyclerView3.setLayoutManager(new LinearLayoutManager(this));
recyclerView3.setAdapter(adapter3);
databaseHelper = new DatabaseHelper(this);
// 向数据库插入数据
databaseHelper.insertData("Data 1");
databaseHelper.insertData("Data 2");
databaseHelper.insertData("Data 3");
// 从数据库查询数据并更新RecyclerView
data1.clear();
data1.addAll(databaseHelper.getData());
adapter1.notifyDataSetChanged();
data2.clear();
data2.addAll(databaseHelper.getData());
adapter2.notifyDataSetChanged();
data3.clear();
data3.addAll(databaseHelper.getData());
adapter3.notifyDataSetChanged();
}
}
请注意,上述代码仅为示例,您可能需要根据您的实际需求进行适当的修改。此外,还需要在布局文件中添加相应的RecyclerView和TextView控件,并创建相应的item布局文件。