以下是一个示例代码,展示了如何在Android中自动在ListView中显示带有复选框的SQLite数据库:
activity_main.xml
,包含一个ListView组件:
list_item.xml
,定义每个ListView项的布局,包含一个复选框和一个文本视图:
DatabaseHelper.java
,用于处理SQLite数据库的创建和查询逻辑: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) {
String createTable = "CREATE TABLE items (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT)";
db.execSQL(createTable);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
String dropTable = "DROP TABLE IF EXISTS items";
db.execSQL(dropTable);
onCreate(db);
}
public void insertItem(String item) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("name", item);
db.insert("items", null, values);
db.close();
}
public List getAllItems() {
List itemList = new ArrayList<>();
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery("SELECT * FROM items", null);
if (cursor.moveToFirst()) {
do {
String item = cursor.getString(cursor.getColumnIndex("name"));
itemList.add(item);
} while (cursor.moveToNext());
}
cursor.close();
db.close();
return itemList;
}
}
public class MainActivity extends AppCompatActivity {
private ListView listView;
private DatabaseHelper databaseHelper;
private List itemList;
private ArrayAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = findViewById(R.id.listView);
databaseHelper = new DatabaseHelper(this);
itemList = databaseHelper.getAllItems();
adapter = new MyAdapter(this, R.layout.list_item, itemList);
listView.setAdapter(adapter);
}
private class MyAdapter extends ArrayAdapter {
private List itemList;
private LayoutInflater inflater;
public MyAdapter(@NonNull Context context, int resource, @NonNull List objects) {
super(context, resource, objects);
itemList = objects;
inflater = LayoutInflater.from(context);
}
@NonNull
@Override
public View getView(final int position, @Nullable View convertView, @NonNull ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.list_item, parent, false);
holder = new ViewHolder();
holder.checkbox = convertView.findViewById(R.id.checkbox);
holder.textview = convertView.findViewById(R.id.textview);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.textview.setText(itemList.get(position));
holder.checkbox.setChecked(false);
holder.checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onChecked