ListView控件拖放

使用ListView控件实现拖放功能可以增强用户体验和交互性。ListView是一种常用的界面组件，用于显示可滚动的列表。拖放功能可以让用户通过拖动列表中的项来改变其位置或进行其他操作。

java
public class DragAndDropActivity extends AppCompatActivity {
    private ListView listView;
    private ArrayAdapter adapter;
    private ArrayList listItems;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_drag_and_drop);
        listView = findViewById(R.id.list_view);
        listItems = new ArrayList<>();
        listItems.add("Item 1");
        listItems.add("Item 2");
        listItems.add("Item 3");
        listItems.add("Item 4");
        listItems.add("Item 5");
        adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, listItems);
        listView.setAdapter(adapter);
        listView.setOnDragListener(dragListener);
        listView.setOnTouchListener(touchListener);
    }
    private View.OnDragListener dragListener = new View.OnDragListener() {
        @Override
        public boolean onDrag(View v, DragEvent event) {
            int action = event.getAction();
            switch (action) {
                case DragEvent.ACTION_DRAG_STARTED:
                    // 拖动开始
                    break;
                case DragEvent.ACTION_DRAG_LOCATION:
                    // 拖动过程
                    break;
                case DragEvent.ACTION_DRAG_ENDED:
                    // 拖动结束
                    break;
                default:
                    break;
            }
            return true;
        }
    };
    private View.OnTouchListener touchListener = new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            if (event.getAction() == MotionEvent.ACTION_DOWN) {
                // 拖动开始
                ClipData data = ClipData.newPlainText("", "");
                View.DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(v);
                v.startDragAndDrop(data, shadowBuilder, v, 0);
                return true;
            }
            return false;
        }
    };
}