java更改选项卡活动

Question

当我为安卓4.0创建一个安卓项目时，你可以选择tabs+swipe，这让我看到了这段代码

import 安卓.app.ActionBar;
import 安卓.app.FragmentTransaction;
import 安卓.content.Context;
import 安卓.os.Bundle;
import 安卓.support.v4.app.Fragment;
import 安卓.support.v4.app.FragmentActivity;
import 安卓.support.v4.app.FragmentManager;
import 安卓.support.v4.app.FragmentPagerAdapter;
import 安卓.support.v4.app.NavUtils;
import 安卓.support.v4.view.ViewPager;
import 安卓.view.Gravity;
import 安卓.view.LayoutInflater;
import 安卓.view.Menu;
import 安卓.view.MenuItem;
import 安卓.view.View;
import 安卓.view.ViewGroup;
import 安卓.widget.TextView;

public class MainActivity extends FragmentActivity implements ActionBar.TabListener {

    /**
     * The {@link 安卓.support.v4.view.PagerAdapter} that will provide fragments for each of the
 * sections. We use a {@link 安卓.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 安卓.support.v4.app.FragmentStatePagerAdapter}.
 */
SectionsPagerAdapter mSectionsPagerAdapter;

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

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_layout);
    // 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 action bar.
    final ActionBar actionBar = getActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    // 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++) {
        // Create a tab with text corresponding to the page title defined by the adapter.
        // Also specify this Activity object, which implements the TabListener interface, as the
        // listener for when this tab is selected.
        actionBar.addTab(
                actionBar.newTab()
                        .setText(mSectionsPagerAdapter.getPageTitle(i))
                        .setTabListener(this));
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main_layout, menu);
    return true;
}



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

public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
    // When the given tab is selected, switch to the corresponding page in the ViewPager.
    mViewPager.setCurrentItem(tab.getPosition());
}

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

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

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

    @Override
    public Fragment getItem(int i) {
        Fragment fragment = new DummySectionFragment();
        Bundle args = new Bundle();
        args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, i + 1);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public int getCount() {
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        switch (position) {
            case 0: return getString(R.string.title_section1).toUpperCase();
            case 1: return getString(R.string.title_section2).toUpperCase();
            case 2: return getString(R.string.title_section3).toUpperCase();
        }
        return null;
    }
}

/**
 * A dummy fragment representing a section of the app, but that simply displays dummy text.
 */
public static class DummySectionFragment extends Fragment {
    public DummySectionFragment() {
    }

    public static final String ARG_SECTION_NUMBER = "section_number";

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        TextView textView = new TextView(getActivity());
        textView.setGravity(Gravity.CENTER);
        Bundle args = getArguments();
        textView.setText(Integer.toString(args.getInt(ARG_SECTION_NUMBER)));
        return textView;
    }
}
}

如何更改tab1的活动我知道如何使用tabhost。setcontent等，但有人能帮我吗？多谢各位

Answer 1

在FragmentActivity中，您可以选择片段，而不是活动，因此您必须为每个场景创建片段，并从getItem（i）返回其中一个片段

如您所见，现在有一个DummySectionFragment，它只包含一个textview。你可以创建并返回你自己的片段

看这个document

例如，您的getItem如下所示：

    @Override
    public Fragment getItem(int i) 
    {
        switch(i)
        {
        case 0:
            Fragment fragment = new MyAwsomeFragment1();
            Bundle args = new Bundle(); //bundle that contains your arguments
            args.putInt(myAwsomeIt); //some args to pass
            fragment.setArguments(args);
            return fragment;
       case 1:
            Fragment fragment = new MyAwsomeFragment2();
            return fragment;
        }
    }