import android.app.Activity;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ListAdapter;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import umd.frenchpronunciationapp.dummy.DummyContent;
/**
* A fragment representing a list of Items.
* <p/>
* Large screen devices (such as tablets) are supported by replacing the ListView
* with a GridView.
* <p/>
* Activities containing this fragment MUST implement the {@link OnFragmentInteractionListener}
* interface.
*/
public class FragmentList1 extends Fragment implements AbsListView.OnItemClickListener{
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
TextView text1;
private Button button1 = (Button) getView().findViewById(R.id.male);
private Button button2 = (Button) getView().findViewById(R.id.female);
ArrayList <String> phrases = new ArrayList<String> ();
private OnFragmentInteractionListener mListener;
/**
* The fragment's ListView/GridView.
*/
private AbsListView mListView;
/**
* The Adapter which will be used to populate the ListView/GridView with
* Views.
*/
private ListAdapter mAdapter;
// TODO: Rename and change types of parameters
public static FragmentList1 newInstance(String param1, String param2) {
FragmentList1 fragment = new FragmentList1();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
/**
* Mandatory empty constructor for the fragment manager to instantiate the
* fragment (e.g. upon screen orientation changes).
*/
public FragmentList1() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
// TODO: Change Adapter to display your content
mAdapter = new ArrayAdapter<DummyContent.DummyItem>(getActivity(),
android.R.layout.simple_list_item_1, android.R.id.text1, DummyContent.ITEMS);
addListenerOnButtonMale();
addListenerOnButtonFemale();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_item, container, false);
// Set the adapter
mListView = (AbsListView) view.findViewById(android.R.id.list);
((AdapterView<ListAdapter>) mListView).setAdapter(mAdapter);
// Set OnItemClickListener so we can be notified on item clicks
mListView.setOnItemClickListener(this);
return view;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public void readInPhrases () throws IOException
{
String str;
InputStream myStream = getResources().openRawResource(R.raw.phrases);
BufferedReader reader = new BufferedReader(new InputStreamReader(myStream));
while ((str = reader.readLine()) != null)
{
phrases.add(str);
}
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
if (null != mListener) {
// Notify the active callbacks interface (the activity, if the
// fragment is attached to one) that an item has been selected.
mListener.onFragmentInteraction(DummyContent.ITEMS.get(position).id);
}
text1 = (TextView) getView ().findViewById (R.id.phrase);
try {
readInPhrases();
}
catch (IOException ex)
{
// catches overidden error ioexecption
}
MediaPlayer mp1 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g1));
MediaPlayer mp2 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g2));
MediaPlayer mp3 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g3));
MediaPlayer mp4 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g4));
MediaPlayer mp5 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g5));
MediaPlayer mp6 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g6));
MediaPlayer mp7 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g7));
MediaPlayer mp8 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g8));
MediaPlayer mp9 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g9));
MediaPlayer mp10 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g10));
MediaPlayer mp11 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g11));
MediaPlayer mp12 = MediaPlayer.create (getActivity().getApplicationContext(), (R.raw.g12));
switch (position){
default:
case 0:
text1.setText (phrases.get(0));
// to incorperate male voice, do this and have male and female buttons
// and a variable that holds true or false if button was pressed
//if (male == true)
mp1.start();
//else
//mp... .start ();
break;
case 1:
text1.setText (phrases.get (1));
mp2.start ();
break;
case 2:
text1.setText (phrases.get (2));
mp3.start ();
break;
case 3:
text1.setText (phrases.get (3));
mp4.start ();
break;
case 4:
text1.setText (phrases.get (4));
mp5.start ();
break;
case 5:
text1.setText (phrases.get (5));
mp6.start ();
break;
case 6:
text1.setText (phrases.get (6));
mp7.start ();
break;
case 7:
text1.setText (phrases.get (7));
mp8.start ();
break;
case 8:
text1.setText (phrases.get (8));
mp9.start ();
break;
case 9:
text1.setText (phrases.get (9));
mp10.start ();
break;
case 10:
text1.setText (phrases.get (10));
mp11.start ();
break;
case 11:
text1.setText (phrases.get (11));
mp12.start ();
break;
}
}
public void addListenerOnButtonMale ()
{
//male.setBackgroundResource((R.drawable.malelogo));
button1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Perform action on click
}
});
}
public void addListenerOnButtonFemale ()
{
//female.setBackgroundResource((R.drawable.femalelogo));
button2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
MediaPlayer mp1 = MediaPlayer.create(getActivity().getApplicationContext(), (R.raw.g1));
mp1.start();
}
});
}
/**
* The default content for this Fragment has a TextView that is shown when
* the list is empty. If you would like to change the text, call this method
* to supply the text it should use.
*/
public void setEmptyText(CharSequence emptyText) {
View emptyView = mListView.getEmptyView();
if (emptyView instanceof TextView) {
((TextView) emptyView).setText(emptyText);
}
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(String id);
}
}
在addListenerOnButtonMale();方法中添加onCreate()会导致我的应用崩溃。我四处寻找可以帮助NullPointerException的答案，但他们都表示我需要在调用方法之前声明button，这对任何事情都没有帮助。
答案 0 :(得分：1)
您的onCreate()：
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
// TODO: Change Adapter to display your content
mAdapter = new ArrayAdapter<DummyContent.DummyItem>(getActivity(),
android.R.layout.simple_list_item_1, android.R.id.text1, DummyContent.ITEMS);
addListenerOnButtonMale();
addListenerOnButtonFemale();
}
您的addListenerOnButtonMale()：
public void addListenerOnButtonMale ()
{
//male.setBackgroundResource((R.drawable.malelogo));
button1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Perform action on click
}
});
}
检查您的onCreate() ...您尚未初始化button1 ..这就是您获得NullPoitnerException的原因。
从addListenerOnButtonMale();
addListenerOnButtonFemale();和onCreate();
修改您的onCreateView()，如下所示：
首先通过查找引用来初始化，然后调用您的方法：
public void onCreateView(){
View view = inflater.inflate(R.layout.fragment_item, container, false);
// Set the adapter
mListView = (AbsListView) view.findViewById(android.R.id.list);
((AdapterView<ListAdapter>) mListView).setAdapter(mAdapter);
// Set OnItemClickListener so we can be notified on item clicks
mListView.setOnItemClickListener(this);
button1 = (Button) view.findViewById(R.id.*button1*);// place id of your button1.
button2 = (Button) view.findViewById(R.id.*button2*);// place id of your button2.
addListenerOnButtonMale();
addListenerOnButtonFemale();
return view;
}