Question

我有一个列表，当用户点击该列表中的项目时，将在该项目下显示三个按钮（即是，否和可能），因此用户可以选择任何一个按钮和该响应（如1,2， 3是for，no，maybe）将被保存。在适配器的getView中，我们只检索该响应并在所有列表项的行上显示imageView

在ArrayAdapter的getView中设置图像

EventUserRelationMO eventUserRelationMO1 =new EventUserRelationMO();
                    eventId1 = eventUserRelationMO1.getEventId();
                    if (eventId1 == eventIdPosition) {
                        long eventUserId = eventUserRelationMO1.getEventUserId();

                        int isAttending = eventUserRelationMO1.getIsAttending();
                        if (isAttending == 1) {
                            holder.no.setVisibility(View.GONE);
                            holder.maybe.setVisibility(View.GONE);
                        } else if (isAttending == 2) {
                            holder.yes.setVisibility(View.GONE);
                            holder.maybe.setVisibility(View.GONE);
                        } else if (isAttending == 3) {
                            holder.yes.setVisibility(View.GONE);
                            holder.no.setVisibility(View.GONE);
                        } else {
                            holder.yes.setVisibility(View.GONE);
                            holder.no.setVisibility(View.GONE);
                            holder.maybe.setVisibility(View.GONE);
                        }

                    }

这是完美无缺的，但当我在列表中有更多项目时，相应的项目不可见/滚动时随机播放

private class UserOccasions extends ArrayAdapter<EventMO> {
        private ArrayList<EventMO> eventMOs;
        LayoutInflater mInflater;

        UserOccasions(Context context, int textViewResourceId,
                      ArrayList<EventMO> eventMOs) {
            super(context, textViewResourceId, eventMOs);
            this.eventMOs = new ArrayList<EventMO>();
            this.eventMOs.addAll(eventMOs);
            mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        }

        public class ViewHolder {
            TextView eventNameTxtV;
            TextView eventPlaceTxtV;
            TextView sendByNameTxtv;
            ImageView yes;
            ImageView no;
            ImageView maybe;

        }

        @Override
        public int getCount() {
            return eventMOs.size();
        }

        /*@Override
        public Object getItem(int position) {
            return position;
        }*/

        @Override
        public long getItemId(int position) {
            return 0;
        }

        // show list values name and mobile number in contact page
        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {
            ViewHolder holder = null;
            final EventMO eventMO = eventMOs.get(position);
            if (null == convertView) {
                convertView = mInflater.inflate(R.layout.invitation, null);
                holder = new ViewHolder();
                holder.eventNameTxtV = (TextView) convertView.findViewById(R.id.invitationTitle);
                holder.eventPlaceTxtV = (TextView) convertView.findViewById(R.id.invitationCheckBox);
                holder.sendByNameTxtv = (TextView) convertView.findViewById(R.id.sendByName);
                holder.yes = (ImageView) convertView.findViewById(R.id.yes);
                holder.no = (ImageView) convertView.findViewById(R.id.no);
                holder.maybe = (ImageView) convertView.findViewById(R.id.maybe);

                eventUserRelationMOs = eventMO.getEventUserRelationBOs();
                sendUserMO = eventMO.getUserBO();
                eventIdPosition = eventMO.getEventId();


                for (EventUserRelationMO eventUserRelationMO1 : eventUserRelationMOs) {
                    eventId1 = eventUserRelationMO1.getEventId();
                    if (eventId1 == eventIdPosition) {
                        long eventUserId = eventUserRelationMO1.getEventUserId();

                        int isAttending = eventUserRelationMO1.getIsAttending();
                        if (isAttending == 1) {
                            holder.no.setVisibility(View.GONE);
                            holder.maybe.setVisibility(View.GONE);
                        } else if (isAttending == 2) {
                            holder.yes.setVisibility(View.GONE);
                            holder.maybe.setVisibility(View.GONE);
                        } else if (isAttending == 3) {
                            holder.yes.setVisibility(View.GONE);
                            holder.no.setVisibility(View.GONE);
                        } else {
                            holder.yes.setVisibility(View.GONE);
                            holder.no.setVisibility(View.GONE);
                            holder.maybe.setVisibility(View.GONE);
                        }

                    }
                }
                convertView.setTag(holder);

            } else {
                holder = (ViewHolder) convertView.getTag();
            }
            holder.yes.setTag(eventMOs.get(position));
            holder.no.setTag(eventMOs.get(position));
            holder.maybe.setTag(eventMOs.get(position));

                       holder.eventNameTxtV.setText(eventMOs.get(position).getText());
            holder.eventPlaceTxtV.setText(eventMOs.get(position).getPlace());
            holder.sendByNameTxtv.setText(sendUserMO.getUserName());

                       View v = convertView.findViewById(R.id.invitation_single);

            v.getRootView().setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                   Intent occasionAct = new Intent(InvitationFragment.this.getActivity(), InvitationActivity.class);
                    occasionAct.putExtra("eventMO", eventMO);
                    occasionAct.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(occasionAct);

                }

            });

            return convertView;

        }

这是我的完整适配器代码，任何人帮我在滚动时为列表中的每个项目维护相应的imageView

Answer 1

ListView通过回收视图来工作。要了解它的工作原理，你可以看一下（http://lucasr.org/2012/04/05/performance-tips-for-androids-listview/）。

代码的问题是当convertView为null时，图像只被设置一次。滚动列表时，列表视图会将循环行传递给getView函数（这时convertView不会为null）。在这种情况下，您没有设置ImageView。

我修改了代码，这应该可行

// show list values name and mobile number in contact page
    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        final EventMO eventMO = eventMOs.get(position);
        if (null == convertView) {
            convertView = mInflater.inflate(R.layout.invitation, null);
            holder = new ViewHolder();
            holder.eventNameTxtV = (TextView) convertView.findViewById(R.id.invitationTitle);
            holder.eventPlaceTxtV = (TextView) convertView.findViewById(R.id.invitationCheckBox);
            holder.sendByNameTxtv = (TextView) convertView.findViewById(R.id.sendByName);
            holder.yes = (ImageView) convertView.findViewById(R.id.yes);
            holder.no = (ImageView) convertView.findViewById(R.id.no);
            holder.maybe = (ImageView) convertView.findViewById(R.id.maybe);
            convertView.setTag(holder);

        } else {
            holder = (ViewHolder) convertView.getTag();
        }


        eventUserRelationMOs = eventMO.getEventUserRelationBOs();
        sendUserMO = eventMO.getUserBO();
        eventIdPosition = eventMO.getEventId();


         for (EventUserRelationMO eventUserRelationMO1 : eventUserRelationMOs) {
            eventId1 = eventUserRelationMO1.getEventId();
            if (eventId1 == eventIdPosition) {
                long eventUserId = eventUserRelationMO1.getEventUserId();

                int isAttending = eventUserRelationMO1.getIsAttending();
                if (isAttending == 1) {
                    holder.no.setVisibility(View.GONE);
                    holder.maybe.setVisibility(View.GONE);
                } else if (isAttending == 2) {
                    holder.yes.setVisibility(View.GONE);
                    holder.maybe.setVisibility(View.GONE);
                } else if (isAttending == 3) {
                    holder.yes.setVisibility(View.GONE);
                    holder.no.setVisibility(View.GONE);
                } else {
                    holder.yes.setVisibility(View.GONE);
                    holder.no.setVisibility(View.GONE);
                    holder.maybe.setVisibility(View.GONE);
                }

            }
        }

        holder.yes.setTag(eventMOs.get(position));
        holder.no.setTag(eventMOs.get(position));
        holder.maybe.setTag(eventMOs.get(position));

        holder.eventNameTxtV.setText(eventMOs.get(position).getText());
        holder.eventPlaceTxtV.setText(eventMOs.get(position).getPlace());
        holder.sendByNameTxtv.setText(sendUserMO.getUserName());

        View v = convertView.findViewById(R.id.invitation_single);

        v.getRootView().setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               Intent occasionAct = new Intent(InvitationFragment.this.getActivity(), InvitationActivity.class);
                occasionAct.putExtra("eventMO", eventMO);
                occasionAct.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(occasionAct);

            }

        });

        return convertView;

    }

滚动时，列表中的项目的ImageView被洗牌

1 个答案: