FragmentPagerAdapter+ViewPager实现Tab切换效果

1.Activity  加载布局文件,获取Viewpager控件   给ViewPager填充适配器.

import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.content.Context;
import android.os.Bundle;
import android.support.v13.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.ActionMode;

import java.util.ArrayList;

public class MainActivity extends Activity {
    private static final String INSTANCESTATE_TAB = "tab";
    ViewPager mViewPager;
    TabsAdapter mTabsAdapter;
    ActionMode mActionMode;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.fragment_pager);
        mViewPager = (ViewPager) findViewById(R.id.pager);

        final ActionBar bar = getActionBar();
        bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
        bar.setDisplayOptions(0, ActionBar.DISPLAY_SHOW_TITLE | ActionBar.DISPLAY_SHOW_HOME);

        mTabsAdapter = new TabsAdapter(this, mViewPager);
        mTabsAdapter.addTab(bar.newTab().setText(R.string.tab_sd),
                Fragment1.class, null);
        mTabsAdapter.addTab(bar.newTab().setText(R.string.tab_remote),
        		Fragment2.class, null);
        if (savedInstanceState != null) {
            bar.setSelectedNavigationItem(savedInstanceState.getInt(INSTANCESTATE_TAB, 0));
        }
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt(INSTANCESTATE_TAB, getActionBar().getSelectedNavigationIndex());
    }

    public void setActionMode(ActionMode actionMode) {
        mActionMode = actionMode;
    }

    public ActionMode getActionMode() {
        return mActionMode;
    }

    public static class TabsAdapter extends FragmentPagerAdapter
            implements ActionBar.TabListener, ViewPager.OnPageChangeListener {
        private final Context mContext;
        private final ActionBar mActionBar;
        private final ViewPager mViewPager;
        private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();

        static final class TabInfo {
            private final Class<?> clss;
            private final Bundle args;
            private Fragment fragment;

            TabInfo(Class<?> _class, Bundle _args) {
                clss = _class;
                args = _args;
            }
        }

        public TabsAdapter(Activity activity, ViewPager pager) {
            super(activity.getFragmentManager());
            mContext = activity;
            mActionBar = activity.getActionBar();
            mViewPager = pager;
            mViewPager.setAdapter(this);
            mViewPager.setOnPageChangeListener(this);
        }

        public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) {
            TabInfo info = new TabInfo(clss, args);
            tab.setTag(info);
            tab.setTabListener(this);
            mTabs.add(info);
            mActionBar.addTab(tab);
            notifyDataSetChanged();
        }

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

        @Override
        public Fragment getItem(int position) {
            TabInfo info = mTabs.get(position);
            if (info.fragment == null) {
                info.fragment = Fragment.instantiate(mContext, info.clss.getName(), info.args);
            }
            return info.fragment;
        }

        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        }

        @Override
        public void onPageSelected(int position) {
            mActionBar.setSelectedNavigationItem(position);
        }

        @Override
        public void onPageScrollStateChanged(int state) {
        }

        @Override
        public void onTabSelected(Tab tab, FragmentTransaction ft) {
            Object tag = tab.getTag();
            for (int i=0; i<mTabs.size(); i++) {
                if (mTabs.get(i) == tag) {
                    mViewPager.setCurrentItem(i);
                }
            }
            if(!tab.getText().equals(mContext.getString(R.string.tab_sd))) {
                ActionMode actionMode = ((MainActivity) mContext).getActionMode();
                if (actionMode != null) {
                    actionMode.finish();
                }
            }
        }

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

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

2.fragment_pager.xml布局文件   里面就一个ViewPager控件   大家记得导入v4包

<?xml version="1.0" encoding="utf-8"?>

<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>

3.Fragment1.java

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class Fragment1 extends Fragment{
	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {
//		return View.inflate(getActivity(), R.layout.fragment1, null);
		return inflater.inflate(R.layout.fragment1,container, false);
	}
}

4.fragment1.xml布局文件

<RelativeLayout 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">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="这是第一个页面" />

</RelativeLayout>

效果图如下: