Question

我有联系人列表。我有一个复选框来选择联系人。我想在另一个列表中添加这些选定的联系人，称为邀请数组列表。如果选中了名为toogleContactsSelection的复选框，我创建了一种方法来添加邀请列表中的所有联系人。这是我在活动中使用的。

如果选中复选框，我创建了另一种在邀请arraylist中添加联系人的方法。

现在，如果未选中复选框，即复选框的onCheckChangeListener，我想从邀请数组列表中删除该对象。

但是对象没有从invitationArrayList中删除。

适配器：

man grep

这是一个活动的代码：

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

        private ArrayList<Contact> contactArrayList;
        private Context mContext;
        public ArrayList<Invitation>  invitationArrayList = new ArrayList<>();

        public class MyViewHolder extends RecyclerView.ViewHolder {
            public TextView name;
            private CheckBox checkBox;

            public MyViewHolder(View view) {
                super(view);
                name = (TextView) view.findViewById(R.id.textContactName);
                checkBox = (CheckBox) view.findViewById(R.id.checkBox);

            }
        }

        public InviteAdapter(Context context, ArrayList<Contact> contactArrayList) {
            this.contactArrayList = contactArrayList;
            this.mContext = context;

        }

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

            return new MyViewHolder(itemView);
        }

        @Override
        public void onBindViewHolder(MyViewHolder holder, final int position) {
            final Contact contact = contactArrayList.get(position);
            holder.name.setText(contact.getmFullName());

            holder.checkBox.setChecked(contact.getSelected());

            holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton compoundButton, boolean b) {

                    if(b)
                    {
                        invite(contact);

                        Log.e("inviteList",String.valueOf(invitationArrayList.size()));
                    }
                    else {
                        invitationArrayList.remove(contact);

                        Log.e("inviteList",String.valueOf(invitationArrayList.size()));
                    }
                }
            });
        }

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

        }

        public void toggleContactsSelection( boolean isSelected ) {
            for( Contact contact : contactArrayList ) {
                contact.setSelected(isSelected);

                    invite(contact);

            }
            notifyDataSetChanged(); // OR you can use notifyItemRangeChanged - which ever suits your needs
        }

        public void invite(Contact contact)
        {

            SharedPreferences sharedpreferences = mContext.getSharedPreferences("UserId", Context.MODE_PRIVATE);

            String mUserId = sharedpreferences.getString("userId","");

            DateFormat df = new SimpleDateFormat("EEE, d MMM yyyy, HH:mm", Locale.ENGLISH);
            String date = df.format(Calendar.getInstance().getTime());

            Invitation invitation = new Invitation();

            invitation.setSender_id(mUserId);
            invitation.setDate(date);
            invitation.setInvitee_no(contact.getmMobileNo());
            invitation.setStatus("0");
            invitation.setUser_name(contact.getmUserName());

            invitationArrayList.add(invitation);

        }

        public void removeInvite(int position)
        {
            invitationArrayList.remove(position);
        }

        public ArrayList<Invitation> getArrayList(){
            return invitationArrayList;
        }

    }


What is going wrong?

EDIT:

This is an adpater :


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

    private ArrayList<Contact> contactArrayList;
    private Context mContext;
    public ArrayList<Invitation>  invitationArrayList = new ArrayList<>();

    public class MyViewHolder extends RecyclerView.ViewHolder {
        public TextView name;
        private CheckBox checkBox;

        public MyViewHolder(View view) {
            super(view);
            name = (TextView) view.findViewById(R.id.textContactName);
            checkBox = (CheckBox) view.findViewById(R.id.checkBox);

        }
    }

    public InviteAdapter(Context context, ArrayList<Contact> contactArrayList) {
        this.contactArrayList = contactArrayList;
        this.mContext = context;

    }

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

        return new MyViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(final MyViewHolder holder, final int position) {
        final Contact contact = contactArrayList.get(holder.getAdapterPosition());
        holder.name.setText(contact.getmFullName());

        holder.checkBox.setChecked(contact.getSelected());

        holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {

                if(b)
                {
                    invite(contact);

                    Log.e("inviteList",String.valueOf(invitationArrayList.size()));
                }
                else {

                    contactArrayList.get(position).setSelected(false);
                 //   holder.checkBox.setChecked(false);
                  // updateInvites();
                    Log.e("inviteList",String.valueOf(invitationArrayList.size()));
                }
            }
        });
    }

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

    }
    public void setChecked()
    {
        for( Contact contact : contactArrayList ) {


        }
    }


    public void toggleContactsSelection( boolean isSelected ) {
        for( Contact contact : contactArrayList ) {
            contact.setSelected(isSelected);

                invite(contact);

        }
        notifyDataSetChanged(); // OR you can use notifyItemRangeChanged - which ever suits your needs
    }

    public void invite(Contact contact)
    {

        Invitation invitation = new Invitation();

            SharedPreferences sharedpreferences = mContext.getSharedPreferences("UserId", Context.MODE_PRIVATE);

            String mUserId = sharedpreferences.getString("userId", "");

            DateFormat df = new SimpleDateFormat("EEE, d MMM yyyy, HH:mm", Locale.ENGLISH);
            String date = df.format(Calendar.getInstance().getTime());

            invitation.setSender_id(mUserId);
            invitation.setDate(date);
            invitation.setInvitee_no(contact.getmMobileNo());
            invitation.setStatus("0");
            invitation.setUser_name(contact.getmUserName());
            invitation.setContact_id(contact.getContactId());

            invitationArrayList.add(invitation);

    }
    public ArrayList<Invitation> getArrayList(){
        return invitationArrayList;
    }

    public void updateInvites(){
        invitationArrayList.clear();
        for(Contact contact : contactArrayList){
            if(contact.getSelected()){

                invite(contact);
            }
        }
    }
}

现在我正在更新onSendInvites列表，但是当我检查或取消选中api时，它的行为不符合预期。

Answer 1

好的，所以我说的很少有愚蠢的错误，

一个。替换

final Contact contact = contactArrayList.get(position);

与

final Contact contact = contactArrayList.get(holder.getAdapterPosition());

湾您正在添加类Invitation的对象

Invitation invitation = new Invitation();
    invitation.setSender_id(mUserId);
    invitation.setDate(date);
    invitation.setInvitee_no(contact.getmMobileNo());
    invitation.setStatus("0");
    invitation.setUser_name(contact.getmUserName());

    invitationArrayList.add(invitation);

℃。您正在尝试删除类Contacts

的对象

else {
                    invitationArrayList.remove(contact);

                    Log.e("inviteList",String.valueOf(invitationArrayList.size()));
                }

<强>解决方案

onBindViewHolder中的

   holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
            contactArrayList.get(holder.getAdapterPosition()).setSelected(b);
            Log.e("inviteList",String.valueOf(invitationArrayList.size()));
            }
        });

然后制作一个类似

的方法

private void updateInvites(){
    invitationArrayList.clear();
    for(Contacts contacts : contactsArrayList){
        if(contacts.isSelected()){
             invite(contact);
        }
    }
}

此处contact.setSeletected(boolean status)和contact.isSelected()分别是setter和getter

编辑： Here is the link to my blog on RecyclerView which explains most of the concepts of Simple RecyclerView.

Answer 2

而不是使用object删除使用索引来删除项目：

   invitationArrayList.remove(position);

它会起作用。

您正在使索引超出范围，因为用户可能会在添加项目之前删除该项目。可能是您的invitationArrayList中不存在的特定元素。因此，请尝试此代码：

if (invitationArrayList!=null && invitationArrayList.size() > 0 && invitationArrayList.size() > position +1){
 invitationArrayList.remove(position);
}

对象未从复选框的列表onCheckedChange侦听器中删除

2 个答案: