使用 listiview 取消选中 Onscroll 选定的复选框

问题描述

在我的应用程序中，我添加了 checkbox 和 ListView，并且我还限制了 checkbox，用户不能选择超过 5 个 checkbox，但问题是滚动我选择的 checkbox 取消选中以下是我的代码片段，任何人都可以帮助我

In my application i added checkbox with ListView,and i also gave limitation for checkbox,user can not select more than 5 checkbox,but the issue is on scroll my selected checkbox get unchecked following is my snippet code,can any one help me with this

public class CustomAdapter extends BaseAdapter {

    private LayoutInflater inflater = null;
    Context context;

    String rup = "u20B9";
    private ArrayList<ModelPooja> listData;
    boolean checked[];

    public CustomAdapterPooja(Context mainActivity, ArrayList<ModelPooja> listData) {
        // TODO Auto-generated constructor stub

        context = mainActivity;
        this.listData = listData;
        inflater = (LayoutInflater) context.
                getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        checked = new boolean[listData.size()];
        for (int i = 0; i < checked.length; i++) {
            checked[i] = listData.get(i).isselected;
        }

    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return listData.size();
    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;
    }


    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
         final ViewHolder holder;

       if (convertView == null) {
        holder = new ViewHolder();
        convertView = inflater.inflate(R.layout.list_item_poojaselection, null);
        holder.tv = (TextView) convertView.findViewById(R.id.list_item_poojaname);
        holder.serviceprice = (TextView) convertView.findViewById(R.id.list_item_poojaprice);
        holder.dayss = (TextView) convertView.findViewById(R.id.list_item_poojadays);
        holder.txtseledates = (TextView) convertView.findViewById(R.id.selecteddatess);
        holder.checks = (CheckBox) convertView.findViewById(R.id.list_item_poojacheck);

       convertView.setTag(holder);

     }else {
           holder = (ViewHolder) convertView.getTag();
       }
        holder.checks.setOnCheckedChangeListener(null);
        holder.checks.setFocusable(false);

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

                if (checkMaxLimit()) {

                    if (listData.get(position).isselected && b) {
                        holder.checks.setChecked(false);
                        listData.get(position).isselected = false;

                    } else {
                        holder.checks.setChecked(false);
                        listData.get(position).isselected = false;
                        Toast.makeText(context, "Max limit reached", Toast.LENGTH_SHORT).show();

                    }
                } else {
                    if (b) {
                        listData.get(position).isselected = true;
                    } else {
                        listData.get(position).isselected = false;
                    }
                }

            }
        });
        if (listData.get(position).isselected()) {
            holder.checks.setChecked(true);
        } else {
            holder.checks.setChecked(false);
        }

        holder.tv.setText(listData.get(position).getPOOJA_LISTING_NAME());
        holder.dayss.setText(listData.get(position).getPOOJA_LISTING_DAYS());
        holder.serviceprice.setText(rup + listData.get(position).getPOOJA_LISTING_AMOUNT());

        return convertView;
    }

    public boolean checkMaxLimit() {
        int countermax = 0;
        for (int i = 0; i < checked.length; i++) {
            checked[i] = false;
            checked[i] = listData.get(i).isselected();
            if (listData.get(i).isselected()) {
                countermax++;
            }
        }
        return countermax >= 5 ? true : false;
    }

    public class ViewHolder {
        TextView tv;
        TextView serviceprice;
        public CheckBox checks;
        public TextView dayss;
        public TextView txtseledates;
    }


}

推荐答案

问题出在您的 getView() 方法中.您设置 OnCheckedChangeListener ，然后将复选框设置为 true 或 false ，这会在该侦听器中触发回调.您应该先设置复选框检查状态，然后再设置 OnCheckedChangeListener.

Problem is in your getView() method. You set OnCheckedChangeListener and after that you set checkbox to true or false which fires callback in that listener. You should set checkbox check state first and after that set OnCheckedChangeListener.

另外，那个布尔值检查[]字段是无用的，所以我稍微简化了你的代码:

Also, that boolean checked[] field is useless, so I simplified your code a little:

 public class CustomAdapter extends BaseAdapter {
    private final LayoutInflater inflater;
    private final Context context;
    private List<ModelPooja> listData;

    public CustomAdapter(Context mainActivity, List<ModelPooja> listData) {
        context = mainActivity;
        this.listData = listData;
        inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

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

    @Override
    public Object getItem(int position) {
        return listData.get(position);
    }

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

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        final ViewHolder holder;

        if (convertView == null) {
            holder = new ViewHolder();
            convertView = inflater.inflate(R.layout.list_item_poojaselection, null);
            holder.tv = (TextView) convertView.findViewById(R.id.list_item_poojaname);
            holder.checks = (CheckBox) convertView.findViewById(R.id.list_item_poojacheck);
            convertView.setTag(holder);
        }else {
            holder = (ViewHolder) convertView.getTag();
        }
        holder.checks.setOnCheckedChangeListener(null);
        holder.checks.setFocusable(false);

        if (listData.get(position).isselected) {
            holder.checks.setChecked(true);
        } else {
            holder.checks.setChecked(false);
        }

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

                if (checkMaxLimit()) {

                    if (listData.get(position).isselected && b) {
                        holder.checks.setChecked(false);
                        listData.get(position).isselected = false;

                    } else {
                        holder.checks.setChecked(false);
                        listData.get(position).isselected = false;
                        Toast.makeText(context, "Max limit reached", Toast.LENGTH_SHORT).show();
                    }
                } else {
                    if (b) {
                        listData.get(position).isselected = true;
                    } else {
                        listData.get(position).isselected = false;
                    }
                }
            }
        });

        holder.tv.setText(listData.get(position).getPOOJA_LISTING_NAME());
        return convertView;
    }

    public boolean checkMaxLimit() {
        int countermax = 0;
        for(ModelPooja item : listData){
            if(item.isselected){
                countermax++;
            }
        }
        return countermax >= 5;
    }

    public class ViewHolder {
        TextView tv;
        public CheckBox checks;
    }
}

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