Android studio连接sqlite的ListView的删除代码

以下是一个简单的Android Studio连接SQLite的ListView的删除代码：

1. 在布局文件中添加ListView：

<ListView
    android:id="@+id/listView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"/>

2. 在MainActivity.java中，定义一个ArrayList和一个CustomAdapter：

public class MainActivity extends AppCompatActivity {

    private ArrayList<Item> itemList;
    private CustomAdapter customAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        itemList = new ArrayList<>();
        customAdapter = new CustomAdapter(this, itemList);

        ListView listView = findViewById(R.id.listView);
        listView.setAdapter(customAdapter);
    }
}

3. 定义一个Item类，包含需要显示的数据：

public class Item {
    private int id;
    private String name;
    private String description;

    public Item(int id, String name, String description) {
        this.id = id;
        this.name = name;
        this.description = description;
    }

    public int getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public String getDescription() {
        return description;
    }
}

4. 定义一个CustomAdapter类，用于为ListView提供数据：

public class CustomAdapter extends BaseAdapter {

    private Context context;
    private ArrayList<Item> itemList;

    public CustomAdapter(Context context, ArrayList<Item> itemList) {
        this.context = context;
        this.itemList = itemList;
    }

    @Override
    public int getCount() {
        return itemList.size();
    }

    @Override
    public Object getItem(int position) {
        return itemList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return itemList.get(position).getId();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        View view = convertView;
        if (view == null) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = inflater.inflate(R.layout.list_item, null);
        }

        TextView nameTextView = view.findViewById(R.id.nameTextView);
        TextView descriptionTextView = view.findViewById(R.id.descriptionTextView);

        Item item = itemList.get(position);
        nameTextView.setText(item.getName());
        descriptionTextView.setText(item.getDescription());

        return view;
    }

    public void removeItem(int position) {
        itemList.remove(position);
        notifyDataSetChanged();
    }
}

5. 在MainActivity.java中，添加一个方法用于从SQLite数据库中加载数据并显示在ListView中：

private void loadItems() {
    itemList.clear();
    DatabaseHelper databaseHelper = new DatabaseHelper(this);
    SQLiteDatabase database = databaseHelper.getReadableDatabase();
    Cursor cursor = database.rawQuery("SELECT * FROM items", null);

    if (cursor.moveToFirst()) {
        do {
            int id = cursor.getInt(cursor.getColumnIndex("id"));
            String name = cursor.getString(cursor.getColumnIndex("name"));
            String description = cursor.getString(cursor.getColumnIndex("description"));
            Item item = new Item(id, name, description);
            itemList.add(item);
        } while (cursor.moveToNext());
    }

    cursor.close();
    database.close();
    customAdapter.notifyDataSetChanged();
}

6. 在MainActivity.java的onCreate方法中调用loadItems方法，以便在应用程序启动时加载数据：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    itemList = new ArrayList<>();
    customAdapter = new CustomAdapter(this, itemList);

    ListView listView = findViewById(R.id.listView);
    listView.setAdapter(customAdapter);

    loadItems();
}

7. 在CustomAdapter类中添加一个方法removeItem，用于从ListView和SQLite数据库中删除项目：

public void removeItem(int position) {
    itemList.remove(position);
    notifyDataSetChanged();

    DatabaseHelper databaseHelper = new DatabaseHelper(context);
    SQLiteDatabase database = databaseHelper.getWritableDatabase();

    int id = itemList.get(position).getId();
    database.delete("items", "id = ?", new String[]{String.valueOf(id)});

    database.close();
}

8. 在MainActivity.java中，为ListView添加一个OnItemLongClickListener，以便在长按列表项时进行删除操作：

listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
    @Override
    public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
        customAdapter.removeItem(position);
        return true;
    }
});

这样，当用户长按ListView中的项时，它将从ListView和SQLite数据库中删除。