How to Handle the checkbox ischecked and unchecked event in android

Question

i am new in android.i make a simple maths apps. i use the check box for select right option but problem is here the answer option is not only one but also two,three means

Answer 1

To Select Maximum 5 Checkbox at one Time or Count selected and unselected checkbox in Custom listview with CheckBox

     package com.test;

 import java.util.ArrayList;
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.app.ListActivity;
 import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;


public class ListViewCheckboxesActivity extends ListActivity {

    AlertDialog alertdialog = null;
    int i1, i2, i3 = 0;
    Country rowcheck;
    MyCustomAdapter dataAdapter = null;
    ListView listView = null;
    int k = 1;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fmain);

        // Generate list View from ArrayList
        displayListView();
        checkButtonClick();

    }

    private void displayListView() {

        // Array list of countries Equipments
        ArrayList rowcheckList = new ArrayList();
        Country rowcheck = new Country("", "Hex Bolts", false);
        rowcheckList.add(rowcheck);
        rowcheck = new Country("", "Hex Cap Screw", false);
        rowcheckList.add(rowcheck);
        rowcheck = new Country("", "Round Head Bolt", false);
        rowcheckList.add(rowcheck);
        rowcheck = new Country("", "Slotted Head Hex Bolt", false);
        rowcheckList.add(rowcheck);
        rowcheck = new Country("", "Socket Cap Screw", false);
        rowcheckList.add(rowcheck);
        rowcheck = new Country("", "Sockets", false);
        rowcheckList.add(rowcheck);
        rowcheck = new Country("", "Square Head Bolt", false);
        rowcheckList.add(rowcheck);
        rowcheck = new Country("", "Carriage Bolt", false);
        rowcheckList.add(rowcheck);
        rowcheck = new Country("", "Plow Bolt", false);
        rowcheckList.add(rowcheck);

        rowcheck = new Country("", "Struts Clamp", false);
        rowcheckList.add(rowcheck);

        listView = getListView();

        dataAdapter = new MyCustomAdapter(this, R.layout.rowcheck_info,
                rowcheckList);

        // Assign adapter to ListView
        listView.setAdapter(dataAdapter);

        listView.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView parent, View view,
                    int position, long id) {
                // When clicked, show a toast with the TextView text
                Country rowcheck = (Country) parent.getItemAtPosition(position);

            }

        });

    }

    private class MyCustomAdapter extends ArrayAdapter {
        private ArrayList rowcheckList;

        public MyCustomAdapter(Context context, int textViewResourceId,
                ArrayList rowcheckList) {
            super(context, textViewResourceId, rowcheckList);
            this.rowcheckList = new ArrayList();
            this.rowcheckList.addAll(rowcheckList);
        }

        private class ViewHolder {
            TextView code;
            CheckBox name;
        }

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

   ViewHolder holder = null;
   Log.v("ConvertView", String.valueOf(position));

   if (convertView == null) 
   {
   LayoutInflater vi = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
   convertView = vi.inflate(R.layout.rowcheck_info, null);

   holder = new ViewHolder();
   holder.code = (TextView) convertView.findViewById(R.id.code);
   holder.name = (CheckBox) convertView.findViewById(R.id.checkBox1);
   convertView.setTag(holder);

    holder.name.setOnClickListener( new View.OnClickListener()
    { 
     public void onClick(View v) 
     { 
      CheckBox cb = (CheckBox) v ; 
      Country rowcheck = (Country) cb.getTag(); 

      //To check maximum 5 Selection
      if(k>5)
      {

          if(!cb.isChecked())
          {


                  rowcheck.selected=true;
                  System.out.println(k--);


           }

          else
          {
              System.out.println("if block in-----");
              cb.setChecked(false);
              Toast.makeText(getApplicationContext(), "Maximum Selection", Toast.LENGTH_LONG).show();
          }


      }

      else
      {

          System.out.println("else block in-----");

          if(!cb.isChecked())
          {


                  rowcheck.selected=true;
                  System.out.println(k--);

           }


          else if(cb.isChecked())
          {


                     rowcheck.selected=false;
                     System.out.println(k++);



          }

      }





     Toast.makeText(getApplicationContext(),
       "Clicked on Checkbox: " + cb.getText() +
       " is " + cb.isChecked(),
       Toast.LENGTH_LONG).show()
       rowcheck.setSelected(cb.isChecked());
     } 
    }); 
   }
   else 
   {
    holder = (ViewHolder) convertView.getTag();
   }

   Country rowcheck = rowcheckList.get(position);
  // holder.code.setText(" (" +  rowcheck.getCode() + ")");
   holder.code.setText(rowcheck.getName());
  // holder.name.setText(rowcheck.getName());
   holder.name.setChecked(rowcheck.isSelected());
   holder.name.setTag(rowcheck);

   return convertView;

  }
    }

    private void checkButtonClick() {

        Button myButton = (Button) findViewById(R.id.findSelected);
        myButton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                StringBuffer responseText = new StringBuffer();
                responseText.append("The following were selected...\n");

                ArrayList rowcheckList = dataAdapter.rowcheckList;

                System.out.println("Size" + rowcheckList.size());
                int j = 0;
                ArrayList stt = new ArrayList();
                for (int i = 0; i < rowcheckList.size(); i++) {
                    Country rowcheck = rowcheckList.get(i);
                    // System.out.println(rowcheck.getName());

                    if (rowcheck.isSelected()) {
                        stt.add(rowcheck.getName());
                        // Country.st=new ArrayList();
                        String s = rowcheck.getName();
                        System.out.println("String--" + rowcheck.getName());
                        Country.st.add(s);
                        j = j++;
                        System.out.println(j++);

                        responseText.append("\n" + rowcheck.getName());

                    }

                }
                for (int i = 0; i < stt.size(); i++) {
                    System.out.println("Names----" + stt.get(i).toString());
                }

                if (j >= 1 && j <= 5) {

                    Intent i = new Intent(ListViewCheckboxesActivity.this,
                            PickedItemListView.class);
                    i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(i);
                } else {
                    Toast.makeText(ListViewCheckboxesActivity.this,
                            "Maximum 5 Selection Allowed", Toast.LENGTH_LONG)
                            .show();
                }

                Toast.makeText(ListViewCheckboxesActivity.this, responseText,
                        Toast.LENGTH_LONG).show();

            }
        });

    }
//Logout ALert Box
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {

            LayoutInflater inflater = LayoutInflater
                    .from(ListViewCheckboxesActivity.this);
            View dialogview = inflater.inflate(R.layout.logout_popup, null);
            final Button ok = (Button) dialogview.findViewById(R.id.ok);
            final Button cancel = (Button) dialogview.findViewById(R.id.cancel);
            AlertDialog.Builder dialogbuilder = new AlertDialog.Builder(
                    (ListViewCheckboxesActivity.this));
            dialogbuilder.setView(dialogview);
            dialogbuilder.setInverseBackgroundForced(true);
            alertdialog = dialogbuilder.create();
            alertdialog.show();

            ok.setOnClickListener(new OnClickListener() {

                public void onClick(View paramView) {
                    alertdialog.dismiss();
                    final Intent intent = new Intent(
                            ListViewCheckboxesActivity.this,
                            LoginActivity.class);
                    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(intent);
                    finish();
                }

            });

            cancel.setOnClickListener(new OnClickListener() {

                public void onClick(View paramView) {
                    alertdialog.cancel();
                }
            });

        }
        return super.onKeyDown(keyCode, event);
    }

}