ViewPager(4)用viewpager实现splash view

1，示例

2，代码

SplashMain.java

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

import com.txw.e.viewpager.R;
import com.txw.e.viewpager.main.MainActivity;

/**
 * A simple {@link Fragment} subclass.
 */
public class SplashMain extends Fragment {


    //1，在layout.xml中添加 ViewPagerFragment,它可以是顶级布局，如下：
    /*
    <?xml version="1.0" encoding="utf-8"?>
    <android.support.v4.view.ViewPager
        android:id="@+id/splash_pager"
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
    */

    //2，准备变量,ViewPager和 PagerAdapter ,OnPageChangeListener
    ViewPager pager;
    SplashViewPagerAdapter pagerAdapter;

    //3，初始化pager
    void initPager(View v){
        //从layout.xml中初始化pager
        pager = (ViewPager) v.findViewById(R.id.splash_pager);

        //初始化page adapter
        pagerAdapter = new SplashViewPagerAdapter(getFragmentManager());

        //设置adapter
        pager.setAdapter(pagerAdapter);

        //设置page切换监听者
        pager.addOnPageChangeListener(onPageChangeListener);

        //设置pager切换动画
//        pager.setPageTransformer(true, new DepthPageTransformer());


    }

    //4，处理 pager 切换事件
    //这里用的ViewPager.SimpleOnPageChangeListener,它什么也不做。
    ViewPager.OnPageChangeListener onPageChangeListener = new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            if (positionOffset == 0){
                for (int i = 0; i < indexer.getChildCount(); ++i){
                    View v = indexer.getChildAt(i);
                    if (i == position){
                        v.setBackgroundResource(R.drawable.splash_indexer_focused);
                    }else{
                        v.setBackgroundResource(R.drawable.splash_indexer);
                    }
                }
            }
        }

        @Override
        public void onPageSelected(int position) {

        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    };

    //5，重写切换动画类，可以把这个类放到外面去。
    public class DepthPageTransformer implements ViewPager.PageTransformer {
        private static final float MIN_SCALE = 0.75f;

        public void transformPage(View view, float position) {
            int pageWidth = view.getWidth();

            if (position < -1) { // [-Infinity,-1)
                // This page is way off-screen to the left.
                view.setAlpha(0);

            } else if (position <= 0) { // [-1,0]
                // Use the default slide transition when moving to the left page
                view.setAlpha(1);
                view.setTranslationX(0);
                view.setScaleX(1);
                view.setScaleY(1);

            } else if (position <= 1) { // (0,1]
                // Fade the page out.
                view.setAlpha(1 - position);

                // Counteract the default slide transition
                view.setTranslationX(pageWidth * -position);

                // Scale the page down (between MIN_SCALE and 1)
                float scaleFactor = MIN_SCALE
                        + (1 - MIN_SCALE) * (1 - Math.abs(position));
                view.setScaleX(scaleFactor);
                view.setScaleY(scaleFactor);

            } else { // (1,+Infinity]
                // This page is way off-screen to the right.
                view.setAlpha(0);
            }
        }
    }


    LinearLayout    indexer;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View v = inflater.inflate(R.layout.fragment_splash_main, container, false);

        initPager(v);

        indexer = (LinearLayout) v.findViewById(R.id.splash_indexer);

        return v;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        MainActivity aty = (MainActivity) getActivity();
        aty.getSupportActionBar().hide();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        MainActivity aty = (MainActivity) getActivity();
        aty.getSupportActionBar().show();
    }
}

SplashViewPagerAdapter.java

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;

public class SplashViewPagerAdapter extends FragmentStatePagerAdapter {


    public SplashViewPagerAdapter(FragmentManager fm) {
        super(fm);

    }

    @Override
    public Fragment getItem(int position) {
        SplashFragment fragment = new SplashFragment();
        fragment.colorId = position;
        return fragment;
    }

    @Override
    public int getCount() {
        return 4;
    }
}

SplashFragment.java

public class SplashFragment extends Fragment {


    public int colors[] = {Color.BLUE,Color.CYAN,Color.GREEN,Color.MAGENTA};

    public View    rootView;
    public int     colorId;

    View.OnClickListener clickListener = new View.OnClickListener(){

        @Override
        public void onClick(View v) {
            if (colorId == 3){
                getFragmentManager().popBackStack();
            }
        }
    };

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        rootView = inflater.inflate(R.layout.fragment_splash, container, false);

        rootView.setBackgroundColor(colors[colorId]);

        rootView.setOnClickListener(clickListener);

        return rootView;
    }

}

 3，xml

fragment_splash_main.xml

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

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
    android:background="#FFFFFF">

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

    <LinearLayout
        android:id="@+id/splash_indexer"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|center_horizontal"
        android:layout_marginBottom="30dp"
        android:orientation="horizontal">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="center_horizontal"
            android:background="@drawable/splash_indexer"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="center_horizontal"
            android:background="@drawable/splash_indexer"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="center_horizontal"
            android:background="@drawable/splash_indexer"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="center_horizontal"
            android:background="@drawable/splash_indexer"/>
    </LinearLayout>

</FrameLayout>

fragment_splash.xml

<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"
             android:background="#FFFFFF"
             tools:context="com.txw.e.viewpager.splash.SplashFragment">
</FrameLayout>

drawable/splash_indexer_focused.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="oval">
    <!--<gradient-->
        <!--android:endColor="#f793ac"-->
        <!--android:gradientRadius="50"-->
        <!--android:startColor="#fa1621"-->
        <!--android:type="radial"/>-->

    <solid android:color="#FFFFFF" />
    <size android:width="20dp" android:height="20dp"/>

</shape>

drawable/splash_indexer.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="oval">
    <gradient
        android:endColor="#fa1621"
        android:gradientRadius="50"
        android:startColor="#f793ac"
        android:type="radial"/>
    <size
        android:width="20dp"
        android:height="20dp"/>

</shape>