Question

我决定使用RecyclerView来显示我的数据列表。每个项目/行中都有一个复选框，2个TextView和一个ImageView。我创建了适配器以处理所有内容，并将选中的项目添加到我的最终列表中。

问题在于，当我检查一些项目并向下滚动时，某些项目将显示为已选中，当我向上滚动时，我之前检查过的项目将显示为未选中。图像和文本视图都可以，但是向下和向上滚动时复选框会混乱。

这是我的适配器：

public class TeamAdapter extends RecyclerView.Adapter<TeamAdapter.MyViewHolder> {

    private Context mContext;
    private List<UserProject> UserList;
    private UserProject user;


    public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
        public TextView name, description;
        public CircleImageView profile_image;
        public CheckBox check;

        public MyViewHolder(View view) {
            super(view);
            name = (TextView) view.findViewById(R.id.name);
            description = (TextView) view.findViewById(R.id.description);
            profile_image = (CircleImageView) view.findViewById(R.id.profile_image);
            check = (CheckBox) view.findViewById(R.id.check);
        }
        @Override
        public void onClick(View v) {
            if (mItemClickListener != null) {
                mItemClickListener.onItemClickListener(v, getAdapterPosition());
            }
        }
    }


    public TeamAdapter(Context mContext, List<UserProject> userList) {
        this.mContext = mContext;
        this.UserList = userList;

    }
    @Override
    public TeamAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.adapter_teams, parent, false);

        return new MyViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(final TeamAdapter.MyViewHolder holder, final int position) {

        user = UserList.get(position);

        holder.name.setText(user.getName());
        holder.description.setText(user.getCompany());

        if(user.getImageURL() != null && !user.getImageURL().isEmpty()) {
            Picasso.with(mContext).load(user.getImageURL()).into(holder.profile_image);
        }

        holder.check.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if(isChecked){
                    ActivityTeams.newList.add(UserList.get(position));
                }else {
                    ActivityTeams.newList.remove(UserList.get(position));
                }
            }
        });

    }


    @Override
    public int getItemCount() {
        return UserList.size();
    }

    private TeamAdapter.onRecyclerViewItemClickListener mItemClickListener;

    public void setOnItemClickListener(TeamAdapter.onRecyclerViewItemClickListener mItemClickListener) {
        this.mItemClickListener = mItemClickListener;
    }

    public interface onRecyclerViewItemClickListener {
        void onItemClickListener(View view, int position);
    }
}

Answer 1

与关于重复答案的评论一样，您的持有人保留复选框视图。您只需根据后备数据更新复选框状态。

在onBindViewHolder中分配检查侦听器之前添加此内容：

holder.check.setOnCheckedChangeListener(null);    
holder.check.setChecked(ActivityTeams.newList.contains(UserList.get(position));
holder.check.setOnCheckedChangeListener(new ... "you know what to do here"

基于此处的CompoundButton源代码https://github.com/android/platform_frameworks_base/blob/master/core/java/android/widget/CompoundButton.java setChecked：

/**
 * <p>Changes the checked state of this button.</p>
 *
 * @param checked true to check the button, false to uncheck it
 */
@Override
public void setChecked(boolean checked) {
    if (mChecked != checked) {
        mCheckedFromResource = false;
        mChecked = checked;
        refreshDrawableState();
        notifyViewAccessibilityStateChangedIfNeeded(
                AccessibilityEvent.CONTENT_CHANGE_TYPE_UNDEFINED);

        // Avoid infinite recursions if setChecked() is called from a listener
        if (mBroadcasting) {
            return;
        }

        mBroadcasting = true;
        if (mOnCheckedChangeListener != null) {
            mOnCheckedChangeListener.onCheckedChanged(this, mChecked);
        }
        if (mOnCheckedChangeWidgetListener != null) {
            mOnCheckedChangeWidgetListener.onCheckedChanged(this, mChecked);
        }
        final AutofillManager afm = mContext.getSystemService(AutofillManager.class);
        if (afm != null) {
            afm.notifyValueChanged(this);
        }

        mBroadcasting = false;
    }
}

正如您所看到的，调用setChecked也会调用当前连接的侦听器。

Answer 2

您没有指定是否在onBindViewHolder（）方法中选中了CheckBox。因此，在创建/回收视图时，RecyclerView无法知道是否选中了CheckBox。

您可以尝试在单独的ArrayList中保存每个相应CheckBox的选中/未选中状态，或者与UserProject类合并并保留信息。

之后，您可以简单地说holder.check.setChecked(...);其中......是CheckBox的条件。

当我向下滚动时，RecyclerView检查错误的项目

2 个答案: