android - 基于按钮点击刷新 fragment View

Question

我有 2 个 fragment (选项卡)共享一些数据。当一个人更改数据时，我希望将其反射(reflect)在另一个选项卡上。我在 stackOverflow 上对此进行了研究，我认为相关答案与 .notifyDataSetChanged() 调用有关，但我无法使其正常工作。这是相关代码...

public class EnterCourseData extends FragmentActivity implements ActionBar.TabListener {

private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
// Tab titles
private String[] tabs = { "Pars", "Handicaps" };
private int courseNumber, teeNumber;
private Tee tee;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_enter_tees);
    // Initilization
    Intent mIntent = getIntent();
    courseNumber = mIntent.getIntExtra("courseNumber",0);
    Course course = Global.getCourse(courseNumber);
    teeNumber = mIntent.getIntExtra("teeNumber",0);
    tee = course.getTee(teeNumber);

    viewPager = (ViewPager) findViewById(R.id.pager);
    actionBar = getActionBar();
    mAdapter = new TabsPagerAdapter(getSupportFragmentManager(), courseNumber, teeNumber);

    viewPager.setAdapter(mAdapter);
    actionBar.setHomeButtonEnabled(false);
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);        

    // Adding Tabs
    for (String tab_name : tabs) {
        actionBar.addTab(actionBar.newTab().setText(tab_name)
                .setTabListener(this));
    }
    /**
     * on swiping the viewpager make respective tab selected
     * */
    viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

        @Override
        public void onPageSelected(int position) {
            // on changing the page
            // make respected tab selected
            actionBar.setSelectedNavigationItem(position);
        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {
        }

        @Override
        public void onPageScrollStateChanged(int arg0) {
        }
    });
}

再往下，这里是需要刷新的 onClick 方法...

public void savePars(View view){
    tee.setSlope(Integer.parseInt(((EditText) findViewById(R.id.enter_tee_slope)).getText().toString()));
    tee.setRating(Double.parseDouble(((EditText) findViewById(R.id.enter_tee_rating)).getText().toString()));
    mAdapter.notifyDataSetChanged();
}

这是 TabsPagerAdapter...

public class TabsPagerAdapter extends FragmentPagerAdapter {
int courseNumber, teeNumber;

public TabsPagerAdapter(FragmentManager fm, int courseNumber, int teeNumber) {
    super(fm);
    this.courseNumber = courseNumber;
    this.teeNumber = teeNumber;
}

@Override
public Fragment getItem(int index) {

    switch (index) {
    case 0:
        // Par Entry activity
        Fragment parFragment = new ParFragment();
        Bundle args = new Bundle();
        args.putInt(ParFragment.ARG_COURSE_NUMBER, courseNumber);
        args.putInt(ParFragment.ARG_TEE_NUMBER, teeNumber);
        parFragment.setArguments(args);
        return parFragment;
    case 1:
        // Handicap Entry fragment activity
        Fragment hcpFragment = new HandicapFragment();
        args = new Bundle();
        args.putInt(HandicapFragment.ARG_COURSE_NUMBER, courseNumber);
        args.putInt(HandicapFragment.ARG_TEE_NUMBER, teeNumber);
        hcpFragment.setArguments(args);
        return hcpFragment;
    }

    return null;
}

@Override
public int getCount() {
    // get item count - equal to number of tabs
    return 2;
}

这是一个 fragment ...

public class ParFragment extends Fragment {
    public static final String ARG_COURSE_NUMBER = "courseNumber", ARG_TEE_NUMBER = "teeNumber";

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_par, container, false);
        Bundle args = getArguments();
        Course course = Global.getCourse(args.getInt(ARG_COURSE_NUMBER));
        ((TextView) rootView.findViewById(R.id.display_course_name)).setText(course.getName());
        Tee tee = course.getTee(args.getInt(ARG_TEE_NUMBER));
        ((TextView) rootView.findViewById(R.id.display_tee_name)).setText(tee.getTeeName());
        ((TextView) rootView.findViewById(R.id.enter_tee_slope)).setText(Integer.toString(tee.getSlope()));
        ((TextView) rootView.findViewById(R.id.enter_tee_rating)).setText(Double.toString(tee.getRating()));

        return rootView;
    }
}

这是另一个......

public class HandicapFragment extends Fragment {
    public static final String ARG_COURSE_NUMBER = "courseNumber", ARG_TEE_NUMBER = "teeNumber";


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_handicap, container, false);
        Bundle args = getArguments();
        Course course = Global.getCourse(args.getInt(ARG_COURSE_NUMBER));
        ((TextView) rootView.findViewById(R.id.display_course_name)).setText(course.getName());
        Tee tee = course.getTee(args.getInt(ARG_TEE_NUMBER));
        ((TextView) rootView.findViewById(R.id.display_tee_name)).setText(tee.getTeeName());
        ((TextView) rootView.findViewById(R.id.enter_tee_slope)).setText(Integer.toString(tee.getSlope()));
        ((TextView) rootView.findViewById(R.id.enter_tee_rating)).setText(Double.toString(tee.getRating()));

        return rootView;
    }

}

单击按钮时，我想保存这些值，并希望这些值显示在另一个 fragment 上。

帮助菜鸟。

谢谢

Answer 1

fragment 之间需要进行通信，但是一个 fragment 不能直接与其他 fragment 进行通信，所有的通信都应该通过持有这些 fragment 的 Activity 来完成。

要遵循的步骤是:

• 在实现了 onClickListener 的 fragment 中定义一个接口(interface)(让它成为 fragment A)

• 在包含这些 fragment 的 Activity 中实现接口(interface)

• 在重写的方法中，从 viewpager 适配器检索 fragment 实例并通过调用它的公共(public)方法将消息传递给 fragment B。

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引用 this answer 从适配器中检索 fragment 实例

有关与其他 fragment 通信的更多详细信息，refer here