Android contact filter not working

import ........

   ContactAdapter objAdapter;
   private ListView listView;
   EditText inputSearch;
   private List<contactbean> list = new ArrayList<contactbean>();

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);       

listView = (ListView) findViewById(R.id.list);
listView.setOnItemClickListener(this);
    inputSearch = (EditText) findViewById(R.id.inputSearch);
    listView = (ListView) findViewById(R.id.list);

    Cursor phones = getContentResolver().query(
            ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, null);
    while (phones.moveToNext()) {
        String name = phones.getString(phones           .getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));

        String phoneNumber = phones.getString(phones                            .getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));

        ContactBean objContact = new ContactBean();
        objContact.setName(name);
        objContact.setPhoneNo(phoneNumber);         
        list.add(objContact);

    }
    phones.close();

   objAdapter = new ContactAdapter(MainActivity.this, R.layout.alluser_row, list);
   listView.setAdapter(objAdapter);
      if (null != list && list.size() != 0) {
        Collections.sort(list, new Comparator<contactbean>() {

            @Override
            public int compare(ContactBean lhs, ContactBean rhs) {
                return lhs.getName().compareTo(rhs.getName());
            }
        });
       } else {
    showToast("No Contact Found!!!");
 }

    inputSearch.addTextChangedListener(new TextWatcher() {

    @Override
    public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
        // When user changed the Text
        MainActivity.this.objAdapter.getFilter().filter(cs);
    }

    @Override
    public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3)                   {
        // TODO Auto-generated method stub   
    }

    @Override
    public void afterTextChanged(Editable arg0) {
        // TODO Auto-generated method stub
    }
});
  }