viewpager+fragment切换页面

布局中上面一个viewpager控件，下面两个textview或者button控件作用于切换页面按钮

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

<android.support.v4.view.ViewPager
    android:id="@+id/vp"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="9">
</android.support.v4.view.ViewPager>
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"
    android:orientation="horizontal">
    <TextView
        android:id="@+id/txt_fl"
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:padding="10dp"
        android:text="分类"/>
    <TextView
        android:id="@+id/txt_gwc"
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:padding="10dp"
        android:text="分类"/>
</LinearLayout>

MainActvity中

public class MainActivity extends FragmentActivity implements View.OnClickListener{

private ViewPager vp;
private TextView txt_fl;
private TextView txt_gwc;
private List<Fragment> fragments;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //初始化控件
    initView();
    //初始化数据
    initData();
}

private void initData() {//添加两个fragment进集合中
    fragments = new ArrayList<>();
    fragments.add(new FlFragment());
    fragments.add(new GwcFragment());
    vp.setAdapter(new FragmentPagerAdapter(getSupportFragmentManager()) {//适配器滑动
        @Override
        public Fragment getItem(int position) {
            return fragments.get(position);
        }

        @Override
        public int getCount() {
            return fragments.size();
        }
    });
    vp.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {//滑动监听
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

        }

        @Override
        public void onPageSelected(int position) {
        ChangbackGround(position);
        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });
}

private void initView() {
    vp = (ViewPager) findViewById(R.id.vp);
    txt_fl = (TextView) findViewById(R.id.txt_fl);
    txt_gwc = (TextView) findViewById(R.id.txt_gwc);
    txt_fl.setOnClickListener(this);
    txt_gwc.setOnClickListener(this);
    txt_fl.setBackgroundColor(Color.GREEN);

}

@Override
public void onClick(View v) {
    switch (v.getId()){
        case R.id.txt_fl:
            vp.setCurrentItem(0);//点击到对应的页面
            ChangbackGround(0);//按钮的背景颜色
            break;
        case R.id.txt_gwc:
            vp.setCurrentItem(1);
            ChangbackGround(1);
            break;
    }
}
public void ChangbackGround(int index){//设置按钮的背景颜色
    txt_fl.setBackgroundColor(index==0? Color.GREEN:Color.WHITE);
    txt_gwc.setBackgroundColor(index==1? Color.GREEN:Color.WHITE);
}

}