ActionBar与ViewPager结合实现“书签导航”

ActionBar与Pager结合实现“书签导航”

首先看MainActivity：

public class MainActivity extends AppCompatActivity implements ActionBar.TabListener{
    private ViewPager viewPager;
    private List<Fragment> list;
    private ActionBar bar;
    private MyFragmentPagerAdapter adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        viewPager = (ViewPager) findViewById(R.id.viewPager);
        list = new ArrayList<>();
        for(int i=0;i<3;i++){

	    //实例化Fragment，并向其传递数据
            MyFragment myFragment = new MyFragment();
            Bundle bundle = new Bundle();
            bundle.putInt("type",i);
            myFragment.setArguments(bundle);
            list.add(myFragment);
        }
        adapter = new MyFragmentPagerAdapter(getSupportFragmentManager(),list);
        viewPager.setAdapter(adapter);

	//获得Activity的ActionBar
        bar = getSupportActionBar();//注意：这里是v7包下的ActionBar

	//设定ActionBar的导航模式
        bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

	//向ActionBar中增加标签页
        bar.addTab(bar.newTab().setText("体育").setTabListener(this));
        bar.addTab(bar.newTab().setText("娱乐").setTabListener(this));
        bar.addTab(bar.newTab().setText("军事").setTabListener(this));

        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {

		//让标签页与ViewPager联动
                bar.setSelectedNavigationItem(position);
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
    }

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

	//ViewPager与标签页联动
        viewPager.setCurrentItem(tab.getPosition());
	
    }

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

    }

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

    }
}

MainActiviy的布局文件：

其中只是放置了一个ViewPager

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.shen.actionbar.MainActivity">

    <android.support.v4.view.ViewPager
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/viewPager"/>
</RelativeLayout>

还有Fragment:

public class MyFragment extends Fragment {


    public MyFragment() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_my, container, false);
        TextView textView = (TextView) view.findViewById(R.id.tvText);

	//接收Activity传来的数据
        Bundle bundle = getArguments();
        int type = bundle.getInt("type");
        switch (type){
            case 0:
                textView.setText("军事");
                break;
            case 1:
                textView.setText("娱乐");
                break;
            case 2:
                textView.setText("体育");
                break;
        }
        return view;
    }

Fragment布局文件:

也很简单，放置一个TextView来显示文本

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="com.shen.actionbar.MyFragment">

    <!-- TODO: Update blank fragment layout -->
    <TextView
        android:id="@+id/tvText"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="myFragmemt" />

</FrameLayout>

当然要进行书签导航翻页，FragmentPagerAdapter也是少不了的。

public class MyFragmentPagerAdapter extends FragmentPagerAdapter {

    private List<Fragment> list;
    public MyFragmentPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    public MyFragmentPagerAdapter(FragmentManager fm, List<Fragment> list) {
        super(fm);
        this.list = list;
    }

    @Override
    public Fragment getItem(int position) {
        return list.get(position);
    }

    @Override
    public int getCount() {
        return list.size();
    }
}

完成这些就可以实现“书签导航”啦~

样式如图：