Question

我在使用单个片段类正确显示和运行ViewPager时遇到了一些麻烦。

所以有点背景知识。活动本身应该允许用户回答调查中的问题。每个问题都包含一个问题标题，一个输入框和一个提交按钮。我已经制作了一个布局和一个相应的片段（QuestionFragment）类来保存所有这些。

我的想法是让ViewPager拥有一堆QuestionFragment，并且用户可以刷到他们想要回答或编辑的问题。基本上每个页面都使用一个QuestionFragment，但每个页面都包含一个独特的问题。

然而，我的实现看起来并不像它的工作。活动的第一页将设置UI（第1页），但其余页面将应用默认布局xml。

注意：目前我正在尝试使用索引号设置UI。您可以忽略Question []数组以及对它的任何引用，因为此时UI不会使用它。但是我确实尝试设置字体，它只适用于第一页。你可以看看底部的截图，“土星有多少个卫星”是布局中的默认xml。我还注意到textview显示问题9，而不是1。

这是片段

public class SurveyTakerFragment extends Fragment {
private Question question;
private int index;
private TextView tv_question_title;
private EditText et_sms_response;
private Button btn_submit_response;
private SharedPreferences sharedPrefs;
private Typeface typeface;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_question, container, false);
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    setup();
}

void setup(){
    Activity activity = getActivity();
    tv_question_title = (TextView) activity.findViewById(R.id.tv_question_title);
    et_sms_response = (EditText) activity.findViewById(R.id.et_sms_response);
    btn_submit_response = (Button) activity.findViewById(R.id.btn_submit_response);
    tv_question_title.setTypeface(typeface);
    tv_question_title.setText("Question: " + index);
    //TODO: Set question title.
    //TODO: Pre-fill previous answer if any.
    btn_submit_response.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            String response = et_sms_response.getText().toString();
            //TODO: Submit response.
        }
    });
}

public void setQuestion(Question question, int index){
    this.question = question;
    this.index = index;
}

public void setSharedPrefs(SharedPreferences sharedPrefs){
    this.sharedPrefs = sharedPrefs;
}

public void setTypeface(Typeface typeface){
    this.typeface = typeface;
}

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
}
}

这是适配器：

public class SurveyTakerAdapter extends FragmentPagerAdapter{

private Question[] questions;
private SharedPreferences sharedPrefs;
private Typeface typeface;

public SurveyTakerAdapter(FragmentManager fm, Question[] questions, 
        SharedPreferences sharedPrefs, Typeface typeface) {
    super(fm);
    this.questions = questions;
    this.sharedPrefs = sharedPrefs;
    this.typeface = typeface;
}

@Override
public Fragment getItem(int index) {
    SurveyTakerFragment surveyTakerFragment = new SurveyTakerFragment();
    surveyTakerFragment.setQuestion(questions[index], index);
    surveyTakerFragment.setSharedPrefs(sharedPrefs);
    surveyTakerFragment.setTypeface(typeface);
    return surveyTakerFragment;
}

@Override
public int getCount() {
    return questions.length;
}

@Override
public CharSequence getPageTitle(int position) {
    return "Question: " + (position + 1);
}
}

寻呼机活动

public class SurveyTaker extends FragmentActivity{
private final String APP_DATA = "appData";
private SurveyTakerAdapter surveyTakerAdapter;
private ViewPager viewPager;

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

    Question[] questions = new Question[10];
    FragmentManager fragmentManager = getSupportFragmentManager();
    SharedPreferences sharedPrefs = getSharedPreferences(APP_DATA, MODE_PRIVATE);
    Typeface robot = Typeface.createFromAsset(getAssets(), "Roboto-Thin.ttf");
    surveyTakerAdapter = new SurveyTakerAdapter(fragmentManager, questions, sharedPrefs, robot);
    viewPager = (ViewPager) findViewById(R.id.vp_survey_taker);
    viewPager.setOffscreenPageLimit(10);
    viewPager.setAdapter(surveyTakerAdapter);
    viewPager.setOnPageChangeListener(new OnPageChangeListener() {

        @Override
        public void onPageSelected(int index) {

        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onPageScrollStateChanged(int arg0) {
            // TODO Auto-generated method stub

        }
    });
}
}

我假设情况就是这样，因为我使用单个片段来填充viewpager中的所有页面，但我不知道怎么回事。我的设计不好吗？或者有什么东西我不见了？

任何帮助将不胜感激！谢谢！

Answer 1

看起来R.id.tv_question_title，R.id.tv_question_title和R.id.tv_question_title视图是R.layout.fragment_question布局的一部分。您应该通过SurveyTakerFragment实例使用getView()，而不是通过Activity通过getActivity()引用这些视图。您还在onActivityCreated()和setup()重复工作。

将onActivityCreated()和setup()实施替换为：

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    setup();
}

void setup(){
    View view = getView();
    tv_question_title = (TextView) view.findViewById(R.id.tv_question_title);
    et_sms_response = (EditText) view.findViewById(R.id.et_sms_response);
    btn_submit_response = (Button) view.findViewById(R.id.btn_submit_response);
    tv_question_title.setTypeface(typeface);
    tv_question_title.setText("Question: " + index);
    //TODO: Set question title.
    //TODO: Pre-fill previous answer if any.
    btn_submit_response.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            String response = et_sms_response.getText().toString();
            //TODO: Submit response.
        }
    });
}

Android ViewPager在多个页面上使用单个Fragment

1 个答案: