setContentView(R.layout.main);

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

  contactSearch = (EditText) findViewById(R.id.contact_search);
  contactSearch.addTextChangedListener(new TextWatcher() {

   public void onTextChanged(CharSequence cs, int start, int before,
     int count) { }

   public void beforeTextChanged(CharSequence arg0, int arg1,
     int arg2, int arg3) {

   }

   public void afterTextChanged(Editable arg0) {

    getContactList(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME
      + " like '"
      + "%"
      + contactSearch.getText().toString()
      + "%'");
   }
  });

  getContactList(null);

 }
public void onItemClick(AdapterView<?> listview, View v, int position,
   long id) {
  ContactBean bean = (ContactBean) listview.getItemAtPosition(position);
  showCallDialog(bean.getName(), bean.getPhoneNo());
 }
private void showCallDialog(String name, final String phoneNo) {
  new AlertDialog.Builder(ContactListActivity.this)
    .setMessage("Are you sure want to call " + name + " ?")
    .setTitle("Call?")
    .setCancelable(true)
    .setPositiveButton("Yes",
      new DialogInterface.OnClickListener() {

       @Override
       public void onClick(DialogInterface dialog,
         int which) {
        String _phoneNumber = "tel:" + phoneNo;
        Intent intent = new Intent(Intent.ACTION_CALL,
          Uri.parse(_phoneNumber));
        startActivity(intent);
       }
      })
    .setNegativeButton("No", new DialogInterface.OnClickListener() {
     @Override
     public void onClick(DialogInterface dialog, int whichButton) {
      dialog.dismiss();
     }
    }).show();
 }

 private void getContactList(String selection) {
  Cursor phones = getContentResolver().query(
    ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,
    selection, null, null);
  phones.moveToFirst();
  ContactBean objContact;
  if (!list.isEmpty()) {
   list.clear();
  }
  while (!phones.isAfterLast()) {
   objContact = new ContactBean();
   String name = phones
     .getString(phones
       .getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
   String phoneNumber = phones
     .getString(phones
       .getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));

   objContact.setName(name);
   objContact.setPhoneNo(phoneNumber);
   list.add(objContact);
   phones.moveToNext();
  }
  phones.close();
objAdapter = new ContactsAdapter(ContactListActivity.this,
    R.layout.alluser_row, list);
  listView.setAdapter(objAdapter);
}

}