要实现在Android RecyclerView中网格可拖动不同的跨度大小,可以按照以下步骤进行:
public class GridItem {
private int spanSize;
private String text;
public GridItem(int spanSize, String text) {
this.spanSize = spanSize;
this.text = text;
}
public int getSpanSize() {
return spanSize;
}
public String getText() {
return text;
}
}
public class GridAdapter extends RecyclerView.Adapter implements ItemTouchHelperAdapter {
private List itemList;
public GridAdapter(List itemList) {
this.itemList = itemList;
}
@NonNull
@Override
public GridViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_grid, parent, false);
return new GridViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull GridViewHolder holder, int position) {
GridItem item = itemList.get(position);
holder.textView.setText(item.getText());
holder.itemView.getLayoutParams().width = holder.itemView.getContext().getResources().getDisplayMetrics().widthPixels / item.getSpanSize();
}
@Override
public int getItemCount() {
return itemList.size();
}
@Override
public void onItemMove(int fromPosition, int toPosition) {
Collections.swap(itemList, fromPosition, toPosition);
notifyItemMoved(fromPosition, toPosition);
}
@Override
public void onItemDismiss(int position) {
itemList.remove(position);
notifyItemRemoved(position);
}
public class GridViewHolder extends RecyclerView.ViewHolder {
TextView textView;
public GridViewHolder(@NonNull View itemView) {
super(itemView);
textView = itemView.findViewById(R.id.textView);
}
}
}
public class ItemTouchHelperCallback extends ItemTouchHelper.Callback {
private final ItemTouchHelperAdapter adapter;
public ItemTouchHelperCallback(ItemTouchHelperAdapter adapter) {
this.adapter = adapter;
}
@Override
public int getMovementFlags(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder) {
int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
int swipeFlags = 0;
return makeMovementFlags(dragFlags, swipeFlags);
}
@Override
public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {
adapter.onItemMove(viewHolder.getAdapterPosition(), target.getAdapterPosition());
return true;
}
@Override
public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) {
adapter.onItemDismiss(viewHolder.getAdapterPosition());
}
@Override
public boolean isLongPressDragEnabled() {
return true;
}
@Override
public boolean isItemViewSwipeEnabled() {
return false;
}
}
List itemList = new ArrayList<>();
itemList.add(new GridItem(1, "Item 1"));
itemList.add(new GridItem(2, "Item 2"));
itemList.add(new GridItem(1, "Item 3"));
itemList.add(new GridItem(3, "Item 4"));
RecyclerView recyclerView = findViewById(R.id.recyclerView);
GridAdapter adapter = new GridAdapter(itemList);
recyclerView.setAdapter(adapter);
ItemTouchHelper.Callback callback = new ItemTouchHelperCallback(adapter);
ItemTouchHelper itemTouchHelper = new ItemTouchHelper(callback);
itemTouchHelper.attachToRecyclerView(recyclerView);
上述代码示例通过创建一个继承自RecyclerView.Adapter的适配器类,并在其中实现了ItemTouchHelperAdapter接口来实现拖动和滑动效果。然后创建一个继承自ItemTouchHelper.Callback的回调类来处理拖动和滑动的操作。最后,在Activity或Fragment中初始化RecyclerView,并将适配器和回调类绑定