Question

我尝试开发一个系统来建立标签和片段之间的关系。您将看到我的代码和视图。

片段管理滑动，并在点击时直接导航导航。

我设法在用户滑动时修改Selected Tab，但我无法做反向。单击选项卡时视图会发生变化。

你明白我的问题并请你解决方案吗？

这是我的主要活动：

public class MainActivity extends FragmentActivity {

/**
 * The {@link android.support.v4.view.PagerAdapter} that will provide
 * fragments for each of the sections. We use a
 * {@link android.support.v4.app.FragmentPagerAdapter} derivative, which
 * will keep every loaded fragment in memory. If this becomes too memory
 * intensive, it may be best to switch to a
 * {@link android.support.v4.app.FragmentStatePagerAdapter}.
 */
SectionsPagerAdapter mSectionsPagerAdapter;

/**
 * The {@link ViewPager} that will host the section contents.
 */
ViewPager mViewPager;
TextView tw;
ActionBar myActionBar;
ArrayList<Category> ListOfCategory;

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

    myActionBar = getActionBar();
    myActionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

     ListOfCategory = new ArrayList<Category>();

    try {
        List<String> categList = new ExecuteJsonLinkTask().execute("http://www.76actu.fr/json.php?d=categories&a=list&key=8smA5YjLG1132zbz301tM94jZO30B7dW").get();

        for (String item : categList) { 

            JSONArray jArray = new JSONArray(item);

            for(int i=0;i<jArray.length();i++){

                JSONObject json_data = jArray.getJSONObject(i);

                Category categ = new Category();
                categ.setCategIdSite(json_data.getInt("term_id"));
                categ.setName(json_data.getString("name"));
                categ.setMoreArticle(true);
                categ.setArticleAvailable(false);

                if(json_data.getInt("term_id") == 89871){
                    categ.setActive(false);
                } else categ.setActive(true);

                Tab tab = myActionBar.newTab(); 
                tab.setText(json_data.getString("name"));
                Object obj = new Object();
                obj = String.valueOf(json_data.getInt("term_id"));
                tab.setTag(obj);
                tab.setTabListener(new MyTabListener(getBaseContext()));
               // tab.setTabListener(new MyTabListener(getBaseContext()));
                myActionBar.addTab(tab);

                ListOfCategory.add(categ);
            }
        }
    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ExecutionException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    // Create the adapter that will return a fragment for each of the three
    // primary sections of the app.
    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mSectionsPagerAdapter);
    mViewPager.setOnPageChangeListener(new OnPageChangeListener() {

        @Override
        public void onPageSelected(int arg0) {
            myActionBar.setSelectedNavigationItem(arg0);

        }

        @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

        }
    });



}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

/**
 * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
 * one of the sections/tabs/pages.
 */
public class SectionsPagerAdapter extends FragmentPagerAdapter {

    private ArrayList<Category> ListOfCategory = new ArrayList<Category>();
    Fragment fragment;
    ActionBar myActionBar;

    public SectionsPagerAdapter(FragmentManager fm){
        super(fm);

        myActionBar = getActionBar();

        try {
            List<String> categList = new ExecuteJsonLinkTask().execute("[API_LINK]").get();

            for (String item : categList) { 

                JSONArray jArray = new JSONArray(item);

                for(int i=0;i<jArray.length();i++){

                    JSONObject json_data = jArray.getJSONObject(i);

                    Category categ = new Category();
                    categ.setCategIdSite(json_data.getInt("term_id"));
                    categ.setName(json_data.getString("name"));
                    categ.setMoreArticle(true);
                    categ.setArticleAvailable(false);

                    if(json_data.getInt("term_id") == 89871){
                        categ.setActive(false);
                    } else categ.setActive(true);

                    ListOfCategory.add(categ);
                }
            }
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (ExecutionException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a DummySectionFragment (defined as a static inner class
        // below) with the page number as its lone argument.
        fragment = new DummySectionFragment();
        Bundle args = new Bundle();
        args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position);
        args.putInt("categId", ListOfCategory.get(position).getCategIdSite());
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public int getCount() {
        // Show total pages.
        return ListOfCategory.size();
    }

    @Override
    public CharSequence getPageTitle(int position) {

        return ListOfCategory.get(position).getName();
    }

}

/**
 * A dummy fragment representing a section of the app, but that simply
 * displays dummy text.
 */
public static class DummySectionFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    TextView dummyTextView;

    public static final String ARG_SECTION_NUMBER = "section_number";

    public DummySectionFragment() {
    }

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

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main_dummy, container, false);
        dummyTextView = (TextView) rootView.findViewById(R.id.section_label);
        int position = getArguments().getInt(ARG_SECTION_NUMBER);
        dummyTextView.setText(Integer.toString(getArguments().getInt("categId")));
        return rootView;
    }

}
public class MyTabListener implements TabListener{ 

    public Context context; 

    MyTabListener(Context context) { 
        this.context = context; 
    } 

    @Override 
    public void onTabReselected(Tab tab, FragmentTransaction ft) {
    } 

    @Override 
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        // HERE
    }

    @Override 
    public void onTabUnselected(Tab tab, FragmentTransaction ft) { 

    }
}
}

这是我的应用程序的屏幕截图：http://i.stack.imgur.com/HBKUj.png

我认为你不需要它，但我可以给你这个。

非常感谢

http://i.stack.imgur.com/HBKUj.png

Answer 1

在我的代码中，我有这个解决方案，它可以工作：

public class MainActivity extends FragmentActivity implements ActionBar.TabListener {

    public static String TAG="MAIN_ACTIVITY";

    public static Context mContext;
    private ViewPager viewPager;
    private TabsPagerAdapter mAdapter;
    private ActionBar actionBar;
    private String[] tabs = { "FRIENDS", "CHAT", "MAP" };



    //ON CREATE METHOD:

   @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mContext = this;
        viewPager = (ViewPager) findViewById(R.id.pager);
        actionBar = getActionBar();
        mAdapter = new TabsPagerAdapter(getFragmentManager());

        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));
        }

        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) {
            }
        });
    }

 @Override
    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft)
    {
        viewPager.setCurrentItem(tab.getPosition());
    }

    @Override
    public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft){}


    @Override
    public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {}

}

TabsPagerAdapter类：

public class TabsPagerAdapter extends FragmentPagerAdapter
{
    public TabsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int index) {

       //switch names of your fragments:
        switch (index) {

            case 0:

                return new Stats_Fragment();
            case 1:

                return new FightsFragment();
            case 2:

                return new SearchFragment();
        }

        return null;
    }

    @Override
    public int getCount() {
        // get item count - equal to number of tabs
        return 3;
    }
}

Answer 2

您必须在Activity xml文件中添加此行，这是我的情况：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="example.com.MainActivity">

//ADD THIS AND PROBLEM WILL BE SOLVED:

    <android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </android.support.v4.view.ViewPager>

</FrameLayout>

Fragment和TabListener之间的关系

2 个答案: