Android RecyclerView添加和删除项目

12 回答

• 4

  首先，应该从列表中删除项目！

  mDataSet.remove(getAdapterPosition());
  

  然后：

  notifyItemRemoved(getAdapterPosition());
    notifyItemRangeChanged(getAdapterPosition(),mDataSet.size());
  

  回复于 2024-04-25T08:10:58+08:00
• 0

  可能是一个重复的答案，但对我来说非常有用 . 您可以在 RecyclerView.Adapter<RecyclerView.ViewHolder> 中实现下面给出的方法，并且可以根据您的要求使用此方法，我希望它对您有用

  public void removeItem(@NonNull Object object) {
          mDataSetList.remove(object);
          notifyDataSetChanged();
      }
  

  回复于 2024-04-25T08:10:58+08:00
• 2

  我遇到的问题是我从列表中删除了一个不再与适配器关联的项目，以确保您正在修改正确的适配器，您可以在适配器中实现这样的方法：

  public void removeItemAtPosition(int position) {
      items.remove(position);
  }
  

  并在您的片段或活动中调用它，如下所示：

  adapter.removeItemAtPosition(position);
  

  回复于 2024-04-25T08:10:58+08:00
• 200

  //////// set the position
   holder.cancel.setTag(position);
  
  
  ///// click to remove an item from recycler view and an array list
  holder.cancel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
  
              int positionToRemove = (int)view.getTag(); //get the position of the view to delete stored in the tag
              mDataset.remove(positionToRemove);
              notifyDataSetChanged();
                  }
              });
  

  回复于 2024-04-25T08:10:58+08:00
• 4

  这是一些视觉补充的例子 . 有关添加和删除范围的示例，请参阅my fuller answer .

  添加单个项目

  在索引 2 添加"Pig" .

  

  String item = "Pig";
  int insertIndex = 2;
  data.add(insertIndex, item);
  adapter.notifyItemInserted(insertIndex);
  

  删除单个项目

  从列表中删除“Pig” .

  

  int removeIndex = 2;
  data.remove(removeIndex);
  adapter.notifyItemRemoved(removeIndex);
  

  回复于 2024-04-25T08:10:58+08:00
• 16

  String str = arrayList.get(position);
    arrayList.remove(str);
    MyAdapter.this.notifyDataSetChanged();
  

  回复于 2024-04-25T08:10:58+08:00
• 2

  将接口转换为自定义适配器类并在回收器视图上处理click事件 .

  onItemClickListner onItemClickListner;
  
  public void setOnItemClickListner(CommentsAdapter.onItemClickListner onItemClickListner) {
      this.onItemClickListner = onItemClickListner;
  }
  
  public interface onItemClickListner {
      void onClick(Contact contact);//pass your object types.
  }
      @Override
  public void onBindViewHolder(ItemViewHolder holder, int position) {
      // below code handle click event on recycler view item.
      holder.itemView.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View view) {
              onItemClickListner.onClick(mContectList.get(position));
          }
      });
  }
  

  在定义适配器并绑定到下面的代码后面的recycleler视图中..

  adapter.setOnItemClickListner(new CommentsAdapter.onItemClickListner() {
          @Override
          public void onClick(Contact contact) {
              contectList.remove(contectList.get(contectList.indexOf(contact)));
              adapter.notifyDataSetChanged();
          }
      });
  }
  

  回复于 2024-04-25T08:10:58+08:00
• 38

  我做了类似的事情 . 在你的_419987中：

  public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
      public CardView mCardView;
      public TextView mTextViewTitle;
      public TextView mTextViewContent;
      public ImageView mImageViewContentPic;
      //......
      public ImageView imgViewRemoveIcon;
      public ViewHolder(View v) {
          super(v);
          mCardView = (CardView) v.findViewById(R.id.card_view);
          mTextViewTitle = (TextView) v.findViewById(R.id.item_title);
          mTextViewContent = (TextView) v.findViewById(R.id.item_content);
          mImageViewContentPic = (ImageView) v.findViewById(R.id.item_content_pic);
          //......
          imgViewRemoveIcon = (ImageView) v.findViewById(R.id.remove_icon);
  
          mTextViewContent.setOnClickListener(this);
          imgViewRemoveIcon.setOnClickListener(this);
          v.setOnClickListener(this);
          mTextViewContent.setOnLongClickListener(new View.OnLongClickListener() {
              @Override
              public boolean onLongClick(View view) {
                  if (mItemClickListener != null) {
                      mItemClickListener.onItemClick(view, getPosition());
                  }
                  return false;
              }
          });
      }
  
  
      @Override
      public void onClick(View v) {
          //Log.d("View: ", v.toString());
          //Toast.makeText(v.getContext(), mTextViewTitle.getText() + " position = " + getPosition(), Toast.LENGTH_SHORT).show();
          if(v.equals(imgViewRemoveIcon)){
              removeAt(getPosition());
          }else if (mItemClickListener != null) {
              mItemClickListener.onItemClick(v, getPosition());
          }
      }
  
  
  }
  
  public void setOnItemClickListener(final OnItemClickListener mItemClickListener) {
      this.mItemClickListener = mItemClickListener;
  }
  
  public void removeAt(int position) {
      mDataset.remove(position);
      notifyItemRemoved(position);
      notifyItemRangeChanged(position, mDataSet.size());
  }
  

  希望这可以帮助 .

  Edit:

  getPosition() 现在被取消使用 getAdapterPosition() .

  回复于 2024-04-25T08:10:58+08:00
• 0

  如果仍然没有删除项目使用这个神奇的方法:)

  private void deleteItem(int position) {
          mDataSet.remove(position);
          notifyItemRemoved(position);
          notifyItemRangeChanged(position, mDataSet.size());
          holder.itemView.setVisibility(View.GONE);
  }
  

  回复于 2024-04-25T08:10:58+08:00
• 1

  如果你想删除项目，你应该这样做：首先删除项目：

  phones.remove(position);
  

  在下一步中，您应该通过此代码通知您的Recycler适配器您删除了一个项目：

  notifyItemRemoved(position);
  notifyItemRangeChanged(position, phones.size());
  

  但如果更改项目，请执行以下操作：首先更改对象的参数，如下所示：

  Service s = services.get(position);
  s.done = "Cancel service";
  services.set(position,s);
  

  或像这样新：

  Service s = new Service();
  services.set(position,s);
  

  然后通过此代码通知您的Recycler适配器您修改了一个项目：

  notifyItemChanged(position);
  notifyItemRangeChanged(position, services.size());
  

  希望能帮助你 .

  回复于 2024-04-25T08:10:58+08:00
• 0

  实际上，使用前面提到的代码（您可以在下面找到），所有RecyclerView子项在删除单个项目时都会生成动画，并且它根本不是响应式解决方案，也因为它有一些潜在的隐藏问题

  public void remove(int position) {
      dataset.remove(position);
      notifyItemRemoved(position);
      notifyItemRangeChanged(position, mDataSet.size());
  }
  

  相反，以下代码片段将在正被删除的子项上播放动画，并且从我的部分它停止抛出 IndexOutOfBoundException s，由调试器标记为"data inconsistency"

  void remove(int position) {
      dataset.removeAt(position);
      notifyItemChanged(position);
      notifyItemRangeRemoved(position, 1);
  }
  

  如果我们深入研究 RecyclerView 类，我们可以找到一个有解释的javadoc，实际上作为第二个参数，我们必须传递从数据集中删除的项目数，而不是项目总数

  /**
       * Notify any registered observers that the <code>itemCount</code> items previously
       * located at <code>positionStart</code> have been removed from the data set. The items
       * previously located at and after <code>positionStart + itemCount</code> may now be found
       * at <code>oldPosition - itemCount</code>.
       *
       * <p>This is a structural change event. Representations of other existing items in the data
       * set are still considered up to date and will not be rebound, though their positions
       * may be altered.</p>
       *
       * @param positionStart Previous position of the first item that was removed
       * @param itemCount Number of items removed from the data set
       */
      public final void notifyItemRangeRemoved(int positionStart, int itemCount) {
          mObservable.notifyItemRangeRemoved(positionStart, itemCount);
      }
  

  回复于 2024-04-25T08:10:58+08:00
• 4

  我尝试了以上所有答案，但是在recyclerview中插入或删除项会导致dataSet中的位置出现问题 . 在viewHolder中使用 delete(getAdapterPosition()); 结束，它非常适合查找项目的位置 .

  回复于 2024-04-25T08:10:58+08:00