Get All Checked Items From a ListView and Retrieve it's To Another Activity

I want to achieve :

1- A ListView of all pdf in device the user can select multiple list items (each item )Using Checkbox (I d'ont want to use multiple selection mode).

2- in action bar button click event with counter (to indicate the number of elements Checked). On button click event , we retrieve the selected list view items using Intent and start another activity (ResultActivity) and displays the result in ListView.

3- save state of ResultActivity when user exits the application so that I can reload this state when the application restarts

I have finished the first part using code bellow

Custom List adapter :

public class CustomList
  extends ArrayAdapter<File> implements CompoundButton.OnCheckedChangeListener
{
  SparseBooleanArray mCheckStates;
  Context context;
  List<File> objects;

  public CustomList(Context paramContext, int paramInt, List<File> paramList)
  {
    super(paramContext, 0, paramList);
    this.context = paramContext;
    this.objects = paramList;
    mCheckStates = new SparseBooleanArray(); 

  }

  public View getView(int paramInt, View paramView, ViewGroup paramViewGroup)         
  {
    View localView = ((LayoutInflater)this.context.getSystemService("layout_inflater"))
            .inflate(R.layout.itemcheck, null, true);
    TextView localTextView1 = (TextView)localView.findViewById(R.id.textView1);
    CheckBox chkSelect = (CheckBox) localView.findViewById(R.id.checkbox_android);

    localTextView1.setText(((File)this.objects.get(paramInt)).getName());

    chkSelect.setTag(paramInt);
    chkSelect.setChecked(mCheckStates.get(paramInt, false));
    chkSelect.setOnCheckedChangeListener(this);
 return localView;
  }
  public boolean isChecked(int position) {
      return mCheckStates.get(position, false);
  }

  public void setChecked(int position, boolean isChecked) {
      mCheckStates.put(position, isChecked);

  }

  public void toggle(int position) {
      setChecked(position, !isChecked(position));

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

   mCheckStates.put((Integer) buttonView.getTag(), isChecked);    

}
}

MainActivity :

    public void search(File paramFile) {
            String pdfPattern = ".pdf";

            File arrayOfFile[] = paramFile.listFiles();

            if (arrayOfFile != null) {
                for (int i = 0; i < arrayOfFile.length; i++) {

                    if (arrayOfFile[i].isDirectory()) {
                        search(arrayOfFile[i]);
                    } else {
                      if (arrayOfFile[i].getName().endsWith(pdfPattern)){

                          File localFile = arrayOfFile[i];
                          this.result.add(localFile.getAbsoluteFile());


                      }
                    }
                }
            }    
        }



      public void onCreate(Bundle paramBundle)
      {
        super.onCreate(paramBundle);
        setContentView(R.layout.listcheck);


// 
        Button b= (Button) findViewById(R.id.button1);
        b.setOnClickListener(new OnClickListener()
        {

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

                StringBuilder result = new StringBuilder();
                for(int i=0;i<customList.mCheckStates.size();i++)
                {
                    if(customList.mCheckStates.get(i)==true)
                    {
                       // here where i want Add the bundle to the intent and start the ResultActivity

                    }

                }
                Toast.makeText(MainActivity.this, result, 1000).show();
            }

        });

        this.progressDialog = ProgressDialog.show(this, "Please Wait ...", "Collecting Pdf files ...");
        this.progressDialog.setCancelable(true); 
        new Thread(new Runnable()
        {
          public void run()
          {
            try
            {
              Thread.sleep(5000L);

              MainActivity.this.progressDialog.dismiss();  
              return;
            }
            catch (Exception localException)
            {
                MainActivity.this.progressDialog.dismiss();
            }
          }
        }).start();
        File localFile = Environment.getExternalStorageDirectory();
       // Log.v("externalpath", localFile);
        search(localFile);
        for (int i = 0;; i++)
        {
          if (i >= this.result.size())
          {

              Collections.sort(this.result, new FilerByName());


             localCustomList = new CustomList(this, 0, this.result);
            this.list = ((ListView)findViewById(R.id.list2));
            this.list.setAdapter(localCustomList);
return;
      }
      Log.v("result", ((File)this.result.get(i)).toString());
    }
  }

  protected void onSaveInstanceState(Bundle paramBundle)
  {
    super.onSaveInstanceState(paramBundle);
  }
  class FilerByName
  implements Comparator<File>
{

  FilerByName() {}

  public int compare(File paramFile1, File paramFile2)
  {
    return String.CASE_INSENSITIVE_ORDER.compare(paramFile1.getName(), paramFile2.getName());
  }
}

}