Try this..
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_kereta_api, container, false);
Button pilihka = (Button) rootView.findViewById(id.btnpilihdgnka);
pilihka.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(getActivity(), PilihDenganKA.class);
startActivity(i);
}
});
return rootView;
}