电脑企业网站设计,珠海网站建设公司有哪些,推广的渠道和方法有哪些,个人做外贸网站违法吗要使用RecyclerView实现手势滑动选中相册图片的功能#xff0c;你需要以下几个步骤#xff1a; 创建含有图片资源的ViewHolder#xff0c;继承自RecyclerView.ViewHolder#xff0c;用于显示相册中的每个图片。 创建一个Adapter#xff0c;继承自RecyclerView.Adapter你需要以下几个步骤 创建含有图片资源的ViewHolder继承自RecyclerView.ViewHolder用于显示相册中的每个图片。 创建一个Adapter继承自RecyclerView.Adapter负责提供数据给ViewHolder。 在Adapter中创建一个内部类ViewHolder用于实例化及绑定每个图片的视图。 实现ItemTouchHelper它提供了滑动和拖放手势的回调接口。 在ItemTouchHelper的onMove方法中处理图片的交换逻辑。
图片适配器
public class ImageAdapter extends RecyclerView.AdapterImageAdapter.ImageViewHolder {private ListAlbumImage imageList;private OnItemClickListener onItemClickListener;public ImageAdapter(ListAlbumImage imageList) {this.imageList imageList;}NonNullOverridepublic ImageViewHolder onCreateViewHolder(NonNull ViewGroup parent, int viewType) {View view LayoutInflater.from(parent.getContext()).inflate(R.layout.album_image_item, parent, false);return new ImageViewHolder(view);}Overridepublic void onBindViewHolder(NonNull ImageViewHolder holder, int position) {AlbumImage image imageList.get(position);holder.bind(image);}Overridepublic int getItemCount() {return imageList.size();}public class ImageViewHolder extends RecyclerView.ViewHolder {private ImageView imageView;public ImageViewHolder(NonNull View itemView) {super(itemView);imageView itemView.findViewById(R.id.imageView);}public void bind(AlbumImage image) {imageView.setImageResource(image.getImageResourceId());}}public interface OnItemClickListener {void onItemClick(AlbumImage image);}public void setOnItemClickListener(OnItemClickListener onItemClickListener) {this.onItemClickListener onItemClickListener;}
}相册图片实体类
public class AlbumImage {private int imageResourceId;public AlbumImage(int imageResourceId) {this.imageResourceId imageResourceId;}public int getImageResourceId() {return imageResourceId;}
}布局文件:
androidx.recyclerview.widget.RecyclerViewandroid:idid/recyclerViewandroid:layout_widthmatch_parentandroid:layout_heightmatch_parent /主Activity
public class MainActivity extends AppCompatActivity {RecyclerView recyclerView;ImageAdapter imageAdapter;Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);recyclerView findViewById(R.id.recyclerView);ListAlbumImage imageList new ArrayList();imageList.add(new AlbumImage(R.drawable.image1));imageList.add(new AlbumImage(R.drawable.image2));imageList.add(new AlbumImage(R.drawable.image3));imageAdapter new ImageAdapter(imageList);recyclerView.setAdapter(imageAdapter);ItemTouchHelper itemTouchHelper new ItemTouchHelper(new ItemTouchHelperCallback(imageAdapter));itemTouchHelper.attachToRecyclerView(recyclerView);imageAdapter.setOnItemClickListener(new ImageAdapter.OnItemClickListener() {Overridepublic void onItemClick(AlbumImage image) {Toast.makeText(MainActivity.this, Selected Image: image.getImageResourceId(), Toast.LENGTH_SHORT).show();}});}private static class ItemTouchHelperCallback extends ItemTouchHelper.Callback {private ImageAdapter adapter;ItemTouchHelperCallback(ImageAdapter adapter) {this.adapter adapter;}Overridepublic boolean isLongPressDragEnabled() {return true;}Overridepublic int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {int dragFlags ItemTouchHelper.UP | ItemTouchHelper.DOWN;int swipeFlags ItemTouchHelper.START | ItemTouchHelper.END;return makeMovementFlags(dragFlags, swipeFlags);}Overridepublic boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {int fromPosition viewHolder.getAdapterPosition();int toPosition target.getAdapterPosition();if (fromPosition toPosition) {for (int i fromPosition; i toPosition; i) {Collections.swap(adapter.imageList, i, i 1);}} else {for (int i fromPosition; i toPosition; i--) {Collections.swap(adapter.imageList, i, i - 1);}}adapter.notifyItemMoved(fromPosition, toPosition);return true;}Overridepublic void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {int position viewHolder.getAdapterPosition();adapter.imageList.remove(position);adapter.notifyItemRemoved(position);}Overridepublic void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {if (actionState ItemTouchHelper.ACTION_STATE_DRAG) {viewHolder.itemView.getBackground().setColorFilter(Color.LTGRAY, PorterDuff.Mode.MULTIPLY);} else if (actionState ItemTouchHelper.ACTION_STATE_SWIPE) {viewHolder.itemView.getBackground().setColorFilter(Color.RED, PorterDuff.Mode.MULTIPLY);} else {viewHolder.itemView.getBackground().clearColorFilter();}super.onSelectedChanged(viewHolder, actionState);}}
}基本的实现流程
1、创建了一个ImageAdapter它包含一个AlbumImage的列表。在每个AlbumImage类中我们有imageResourceId它是图片的资源ID。ImageViewHolder类是RecyclerView.ViewHolder的一个内部类它绑定每个图片视图。
2、ItemTouchHelperCallback类扩展了ItemTouchHelper.Callback它处理滑动和拖动手势。在onMove方法中我们交换了ImageAdapter中的AlbumImage对象以确保视图反映底层数据的变化。在onSwiped方法中我们从ImageAdapter的列表中移除项目并通知适配器。
