问题描述
我正在尝试为textview设置一个字符串，但是每次我单击测验按钮时，活动只是刷新，而不是分段活动。
这样总结了情况。
- 我在名为Quiz_Container的活动中有动态viewPager
- 在公共Fragment getItem（int位置）或FragmentStatePagerAdapter中仅使用一个fragment（Module_Topics_Content_Quiz）。
- 我想每次滑动时从活动中更改片段中的textview文本。
- 我正在使用带有参数的newInstance将字符串从活动传递到片段
- 字符串来自quizQuestion.get（position）
- 我使用Log.d获取正确的值，但是将其设置为textview时，活动只是在刷新。
这是我的代码。
Quiz_Container.java
public class Quiz_Container extends AppCompatActivity implements Module_Topics_Content_Quiz.OnFragmentInteractionListener {
android.support.v7.app.ActionBar actionBar;
ViewPager quizPager;
private int topicID;
private int moduleID;
private int subModuleID;
private ArrayList<Integer> quizID;
private ArrayList<String> quizQuestion;
private ArrayList<String> choiceA;
private ArrayList<String> choiceB;
private ArrayList<String> choiceC;
private ArrayList<String> choiceD;
private ArrayList<String> quizAnswer;
private FragmentManager fragmentManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_quiz__container);
actionBar = getSupportActionBar();
actionBar.setTitle("Quiz");
actionBar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#f1ad1e")));
Bundle extras = getIntent().getExtras();
topicID = extras.getInt("topicID");
moduleID = extras.getInt("moduleID");
subModuleID = extras.getInt("subModuleID");
Log.d("quizTopicID", "" + topicID);
Log.d("quizModuleID", "" + moduleID);
Log.d("quizSubModuleID", "" + subModuleID);
new quizTask().execute();
}
@Override
public void onFragmentInteraction(Uri uri) {
}
public boolean isOnline() {
ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnectedOrConnecting()) {
return true;
} else {
return false;
}
} // Check Internet Connection
class quizTask extends AsyncTask<String, String, String> {
@Override
protected void onPreExecute() {
}
@Override
protected String doInBackground(String... params) {
BufferedReader reader = null;
try {
URL quizURL = new URL("http://192.168.1.110/science/index.php/users/get_quiz_items/" + topicID + "/" + moduleID + "/" + subModuleID + "" );
HttpURLConnection con = (HttpURLConnection)quizURL.openConnection();
StringBuilder sb = new StringBuilder();
reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
String quizResponse;
while ((quizResponse = reader.readLine()) != null) {
return quizResponse;
}
return sb.toString();
} catch (IOException e) {
e.printStackTrace();
return null;
} finally {
if(reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
}
}
@Override
protected void onPostExecute(String quizResponses) {
Log.d("quizResponse", "" + quizResponses);
try {
JSONObject quizObject = new JSONObject(quizResponses);
boolean result = quizObject.getBoolean("success");
if (result) {
JSONArray quizArray = quizObject.getJSONArray("data");
quizID = new ArrayList<>();
quizQuestion = new ArrayList<>();
choiceA = new ArrayList<>();
choiceB = new ArrayList<>();
choiceC = new ArrayList<>();
choiceD = new ArrayList<>();
quizAnswer = new ArrayList<>();
for (int i = 0; i < quizArray.length(); i ++) {
JSONObject dataQuiz = quizArray.getJSONObject(i);
quizID.add(dataQuiz.getInt("id"));
quizQuestion.add(dataQuiz.getString("question"));
choiceA.add(dataQuiz.getString("a"));
choiceB.add(dataQuiz.getString("b"));
choiceC.add(dataQuiz.getString("c"));
choiceD.add(dataQuiz.getString("d"));
quizAnswer.add(dataQuiz.getString("answer"));
}
Log.d("quizSize", "" + quizID.size());
quizPager = (ViewPager) findViewById(R.id.quizPager);
fragmentManager = Quiz_Container.this.getSupportFragmentManager();
quizPager.setAdapter(new quizAdapter(getSupportFragmentManager()));
quizPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
else {
Toast.makeText(getApplication(), "no quiz yet", Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
} // end of quizTask
class quizAdapter extends FragmentStatePagerAdapter {
public quizAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
Fragment fragment = null;
for (int i = 0; i < quizID.size; i++) {
if (i == position) {
fragment = Module_Topics_Content_Quiz.newInstance(quizQuestion.get(position));
Log.d("testQuestion", "" + quizQuestion.get(position)); // this code is working
}
}
return fragment;
}
@Override
public int getCount() {
return quizID.size();
}
}
}
Module_Topics_Content_Quiz.java
public class Module_Topics_Content_Quiz extends Fragment {
TextView textQuizQuestion;
private String qQuestion;
public Module_Topics_Content_Quiz() {
// Required empty public constructor
}
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(Uri uri);
}
public static Module_Topics_Content_Quiz newInstance(String question) {
Module_Topics_Content_Quiz fragment = new Module_Topics_Content_Quiz();
Bundle args = new Bundle();
args.putString("question", question);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
qQuestion = getArguments().getString("question");
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.fragment_module__topics__content__quiz, container, false);
textQuizQuestion = (TextView) getActivity().findViewById(R.id.textQuestion);
Log.d("question", "" + qQuestion); // this is working
// textQuizQuestion.setText(qQuestion); // error if enable
return rootView;
}
}
请帮忙。 谢谢。
1楼
在您的片段中，尝试使用返回的View而不是使用getActivity()来getActivity() TextView
您需要使Fragment的视图膨胀，并在返回的View上调用findViewById() 。
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.fragment_module__topics__content__quiz, container, false);
// inflate the View inside Fragment using the View returned
textQuizQuestion = (TextView) rootView.findViewById(R.id.textQuestion);
Log.d("question", "" + qQuestion); // this is working
textQuizQuestion.setText(qQuestion);
return rootView;
}
您还可以在Fragment中使用getView()获取根视图。
如果您想从随附的活动中致电，请使用
getFragmentManager().findFragmentById(R.id.your_fragment_id).getView().findViewById(R.id.your_view);