how to limit checkbox selection in listview?

friends,

i want to limit checkbox selection in android listivew to for example only 3 checkboxes should be selected otherwise it should give error message.

user can select any three checkboxes from the list any one guide me how to achieve this? here is my adapter

public class AdapterContacts extends BaseAdapter  {

    private LayoutInflater mInflater;

    public Context context;
    public static List<myContacts> contacts;

    public AdapterContacts(Context context,List<myContacts> list) {
      mInflater = LayoutInflater.from(context);
      this.context = context;
      contacts= list;
    }

    public View getView(final int position, View convertView, ViewGroup parent) {

      ViewHolder holder;

      if (convertView == null) {
        convertView = mInflater.inflate(R.layout.list_contacts, nul开发者_如何学Pythonl);
        holder = new ViewHolder();
        holder.contactName = (TextView) convertView.findViewById(R.id.contactName);
        holder.contactNumber = (TextView) convertView.findViewById(R.id.contactNumber);
        holder.checkBox = (CheckBox) convertView.findViewById(R.id.checkBox);
        convertView.setTag(holder);

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

      myContacts contact = getItem(position);
      holder.checkBox.setOnCheckedChangeListener(new OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(CompoundButton checkboxView, boolean isChecked) {
                 myContacts c = (myContacts) checkboxView.getTag();
                 c.setSelected(isChecked);
                 // to put that check of selection limit with error


            }
        });


      holder.checkBox.setTag(contact);
      holder.checkBox.setChecked(contact.isSelected());



      holder.contactName.setText(contact.getContactName());
      holder.contactNumber.setText(contact.getPhoneNumber());

        return convertView;

        }

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

    @Override
    public myContacts getItem(int position) {
        return contacts.get(position);
    }

    @Override
    public long getItemId(int arg0) {
        return 0;
    }


    class ViewHolder {
        TextView contactName;
        TextView contactNumber;
        CheckBox  checkBox;
      }




}

any help would be appreciated.

finally i solved this issue :) where as globalInc is global variable with default value 0

holder.checkBox.setOnCheckedChangeListener(new OnCheckedChangeListener() 
      {

            @Override
            public void onCheckedChanged(CompoundButton checkboxView, boolean isChecked) 
            {
                 myContacts c = (myContacts) checkboxView.getTag();

                 if(isChecked)
                 {
                     globalInc++;
                 }
                 else if(!isChecked)
                 {
                     globalInc--;
                 }
                 if(globalInc >= 4)// it will allow 3 checkboxes only
                 {
                     Toast.makeText(context, "Error = " + globalInc, Toast.LENGTH_LONG).show();
                     checkboxView.setChecked(false);
                     globalInc--;
                 }
                 else
                 {
                    c.setSelected(isChecked);
                 }
                 System.out.println(" ---------------    "+globalInc);
            }
        });

i solved the issue "after scroll listview user can also again select more than 3 check boxex" Thanks for you patience set static int count = 0;

                     if (isChecked) {
                        count++;
                    } else if (!isChecked) {
                        count--;
                    }

                    if (count >= 4) {
                        buttonView.setChecked(false);
                        count--;
                    } else {
                        int getPosition = (Integer) buttonView.getTag();

                       contact.get(getPosition).setSelected(buttonView.isChecked());
                    } 

And Most imprtant is that add count=0 in else and viewHolder.chkContact.setTag(position) after else;

if(convertView == null){   

}else
{
 viewHolder = (ViewHolder) convertView.getTag();
 count=0;
 }
 viewHolder.chkContact.setTag(position);

`

Take a static int count variable and increment it using these condition

holder.checkBox.isChecked() if it is true then increment in the count then check count>3 then show popup to user

I hope this is Help.

int globalInc = 0;
boolean isCheckGlobal = false;

ArrayList<Integer> checkings = new ArrayList<Integer>();

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

    ViewHolder viewHolder = null;
    if (convertView == null) {
        LayoutInflater inflator = context.getLayoutInflater();
        convertView = inflator.inflate(R.layout.list_inner, null);
        viewHolder = new ViewHolder();
        viewHolder.friendName = (TextView) convertView
                .findViewById(R.id.friendName);

        viewHolder.checkbox = (CheckBox) convertView
                .findViewById(R.id.checkbox);

        final MyAdapterSecond objectMyAdapter = new MyAdapterSecond();

        viewHolder.checkbox.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                int getPositionInClick = (Integer) v.getTag();


                if (isCheckGlobal == false) {
                    if (checkings.contains(getPositionInClick)) {
                        globalInc--;
                        checkings.remove(checkings.indexOf(getPositionInClick));
                                                } else {
                        objectMyAdapter.getCheck(false);
                    }
                } else if (isCheckGlobal == true) {
                                            if (checkings.size() < 4) {
                        globalInc++;
                    }

                }
            }
        });

        viewHolder.checkbox
                .setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

                    @Override
                    public void onCheckedChanged(CompoundButton buttonView,
                            boolean isChecked) {
                        int getPosition = (Integer) buttonView.getTag();



                        list.get(getPosition).setSelected(
                                buttonView.isChecked());                            

                        callCheck(buttonView, "hi1");
                        if (checkings.size() > 4                            {
                            Toast.makeText(context, "Error = " + globalInc,
                                    Toast.LENGTH_LONG).show();
                                                            objectMyAdapter.setCheck(buttonView);
                            isCheckGlobal = false;


                        } else {
                            buttonView.setSelected(isChecked);
                            if (isChecked
                                    && (!checkings.contains(getPosition))) {
                                checkings.add(getPosition);
                                                                }
                            else if(!isChecked){
                                if(checkings.contains(getPosition)){
                                    checkings.remove(checkings.indexOf(getPosition));
                                }
                            }
                            isCheckGlobal = true;
                                                        }

                    }
                });
        convertView.setTag(viewHolder);
        convertView.setTag(R.id.friendName, viewHolder.friendName);

        convertView.setTag(R.id.checkbox, viewHolder.checkbox);
    } else {
        viewHolder = (ViewHolder) convertView.getTag();
    }
    viewHolder.checkbox.setTag(position); // This line is important.

    viewHolder.friendName.setText(list.get(position).getname());

            viewHolder.checkbox.setChecked(list.get(position).isSelected());

    return convertView;

 }


 class MyAdapterSecond {
    CompoundButton buttonView;

    public void setCheck(CompoundButton buttonView) {
        this.buttonView = buttonView;
    }

    public void getCheck(boolean flag) {
        this.buttonView.setChecked(flag);
    }
}

Try this:

public class AccountListAdapter extends BaseAdapter {

@SuppressWarnings("unused")
private final static String TAG = AccountListAdapter.class.getSimpleName();

private Context context;
private List<Account> rowItems;

private int selectedItemCounter = 0;

private final int limit;

public AccountListAdapter(Context context, List<Account> items, int limit) {
    this.context = context;
    this.rowItems = items;
    this.limit = limit;
}

public View getView(final int position, View convertView, ViewGroup parent) {

    LayoutInflater mInflater = (LayoutInflater) context
            .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);

    final Account rowItem = (Account) getItem(position);

    convertView = mInflater.inflate(R.layout.account_selection_item, null);

    TextView tv = (TextView) convertView.findViewById(R.id.textView);
    ToggleButton tb = (ToggleButton) convertView
            .findViewById(R.id.toggleButton);

    tb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

        @Override
        public void onCheckedChanged(CompoundButton buttonView,
                boolean isChecked) {

            if (isChecked && !rowItem.isSelected()) {

                if (selectedItemCounter >= limit) {
                    Toast.makeText(context,
                            "can't be more" + selectedItemCounter,
                            Toast.LENGTH_SHORT).show();
                    buttonView.setChecked(false);
                    return;
                }

                rowItem.setSelected(true);
                selectedItemCounter++;
            } else if (!isChecked && rowItem.isSelected()) {
                rowItem.setSelected(false);
                selectedItemCounter--;
            }

        }
    });

    tv.setText(rowItem.getDevId());
    tb.setChecked(rowItem.isSelected());

    return convertView;
}

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

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

@Override
public long getItemId(int position) {
    return rowItems.indexOf(getItem(position));
}
}

tried to improve my code with ViewHolder pattern but failed. if anyone have better idea, please let me know.