Question

我在我的主要活动中使用Eclipse模板，该模板使用带有滑动视图的选项卡。总共有5个选项卡，每个选项卡将托管应用程序的一部分。我正在使用标有“Personnel”的标签开始实施。当用户首次选择Personnel选项卡时，他们将获得ListView人员列表。当用户从列表中选择一个人时，我想在旧的顶部创建一个新的片段（就像开始一个新的活动一样），但是在同一个标签中。当用户导航到新选项卡然后返回时，详细视图仍应存在。关闭详细信息视图后，应重新启动人员列表。

如何在单个标签中创建新片段并保留整个标签的状态？

MainActivity.java

import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.Menu;
import android.view.MenuItem;

import java.util.Locale;

public class MainActivity extends FragmentActivity implements ActionBar.TabListener,
        UnitsFragment.OnUnitSelectedListener {

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

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

        @Override
        public int getCount() {
            // Show 5 total pages.
            return 5;
        }

        @Override
        public Fragment getItem(int position) {
            // getItem is called to instantiate the fragment for the given page.
            switch (position) {
                case 0:
                    return new AccountabilityFragment();
                case 1:
                    return new EventsFragment();
                case 2:
                    return new MeFragment();
                case 3:
                    return new PersonnelFragment();
                case 4:
                    return new UnitsFragment();
            }
            return null;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            Locale l = Locale.getDefault();
            switch (position) {
                case 0:
                    return getString(R.string.title_section1).toUpperCase(l);
                case 1:
                    return getString(R.string.title_section2).toUpperCase(l);
                case 2:
                    return getString(R.string.title_section3).toUpperCase(l);
                case 3:
                    return getString(R.string.title_section4).toUpperCase(l);
                case 4:
                    return getString(R.string.title_section5).toUpperCase(l);
            }
            return null;
        }
    }

    /**
     * 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;
    static boolean mShowMenuAdd = true;
    static boolean mShowMenuSearch = true;

    /**
     * The {@link ViewPager} that will host the section contents.
     */
    ViewPager mViewPager;

    @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;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.action_add:
                return true;
            case R.id.action_search:
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        menu.findItem(R.id.action_add).setVisible(mShowMenuAdd);
        menu.findItem(R.id.action_search).setVisible(mShowMenuSearch);
        return true;
    }

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

    @Override
    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
        // When the given tab is selected, switch to the corresponding page in
        // the ViewPager.
        mShowMenuAdd = setMenuAddVisible(tab.getPosition());
        mShowMenuSearch = setMenuSearchVisible(tab.getPosition());
        invalidateOptionsMenu();
        mViewPager.setCurrentItem(tab.getPosition());
    }

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

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

        // Set up the action bar.
        final ActionBar actionBar = getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        // Create the adapter that will return a fragment for each of the five
        // 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);

        // When swiping between different sections, select the corresponding
        // tab. We can also use ActionBar.Tab#select() to do this if we have
        // a reference to the Tab.
        mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                actionBar.setSelectedNavigationItem(position);
            }
        });

        // For each of the sections in the app, add a tab to the action bar.
        for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
            actionBar.addTab(
                    actionBar.newTab()
                            .setText(mSectionsPagerAdapter.getPageTitle(i))
                            .setTabListener(this));
        }

    }

    private boolean setMenuAddVisible(int tab) {
        switch (tab) {
            case 0:
                return false;
            case 1:
                return false;
            case 2:
                return false;
            case 3:
                return false;
            case 4:
                return true;
        }
        return false;
    }

    private boolean setMenuSearchVisible(int tab) {
        switch (tab) {
            case 0:
                return false;
            case 1:
                return false;
            case 2:
                return false;
            case 3:
                return false;
            case 4:
                return true;
        }
        return false;
    }
}

PersonnelFragment.java

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class PersonnelFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_personnel, container, false);
        TextView dummyTextView = (TextView) rootView.findViewById(R.id.textUnitsHeader);
        dummyTextView.setText("Personnel Layout Placeholder");
        return rootView;
    }
}

Answer 1

我添加了一个新布局作为根视图，并在单个选项卡中托管一堆片段。我偶然发现了一些视频，它展示了我正在寻找并实施它的行为。

非常感谢GitHub用户Dani Lao提供的source code。

我的实施：

<强> activity_main.xml中

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

<强> MainActivity.java

...

public class MainActivity extends FragmentActivity {

    SectionsPagerAdapter mSectionsPagerAdapter;
    ViewPager mViewPager;
    ...
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.action_add:
                android.support.v4.app.FragmentTransaction ft = getSupportFragmentManager()
                        .beginTransaction();
                ft.replace(R.id.personnel_root, new PersonnelViewFragment());
                ft.setTransition(android.support.v4.app.FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
                ft.addToBackStack(null);
                ft.commit();
                return true;
            case R.id.action_search:
                ft = getSupportFragmentManager()
                        .beginTransaction();
                ft.replace(R.id.personnel_root, new PersonnelListFragment());
                ft.setTransition(android.support.v4.app.FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
                ft.addToBackStack(null);
                ft.commit();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }
    ...
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final ActionBar actionBar = getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        mSectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager());

        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                actionBar.setSelectedNavigationItem(position);
            }
        });
        ActionBar.TabListener actionBarTabListener = new ActionBar.TabListener() {

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

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

            @Override
            public void onTabReselected(Tab tab, FragmentTransaction ft) {
            }
        };
        // For each of the sections in the app, add a tab to the action bar.
        for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
            actionBar.addTab(
                    actionBar.newTab()
                            .setText(mSectionsPagerAdapter.getPageTitle(i))
                            .setTabListener(actionBarTabListener));
        }
    }
}

fragment_personnel_root.xml （新）

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/personnel_root"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

</FrameLayout>

PersonnelRootFragment.java （新）

public class PersonnelRootFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_personnel_root, container, false);

        FragmentTransaction fragmentTransaction = getActivity().getSupportFragmentManager()
                .beginTransaction();
        fragmentTransaction.replace(R.id.personnel_root, new PersonnelListFragment());
        fragmentTransaction.commit();
        return rootView;
    }
}

<强> fragment_personnel_list.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/textPersonnelHeader"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/text_all_personnel"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:textColor="@color/mc_med_brown" />

    <EditText
        android:id="@+id/editTextPersonnelSearch"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="@string/search_hint" >

        <requestFocus />
    </EditText>

    <ListView
        android:id="@+id/listViewPersonnel"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textFilterEnabled="true" >
    </ListView>

</LinearLayout>

如何在ActionBar选项卡中添加片段？

1 个答案: