ViewPager渲染背景颜色渐变(引导页)--第三方开源--ColorAnimationView

<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" >

    <com.lgl.viewpager.ColorAnimationView
        android:id="@+id/ColorAnimationView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:padding="30dp" />

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <Button
            android:id="@+id/btn_go"
            android:layout_width="100dp"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_centerHorizontal="true"
            android:layout_marginBottom="43dp"
            android:background="@drawable/colorbu"
            android:text="开始"
            android:visibility="gone" />
    </RelativeLayout>

</FrameLayout>

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends FragmentActivity {
    private static final int[] resource = new int[] { R.drawable.welcome1,
            R.drawable.welcome4, R.drawable.welcome3, R.drawable.welcome4 };
    private static final String TAG = MainActivity.class.getSimpleName();
    private Button btn_go;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn_go = (Button) findViewById(R.id.btn_go);
        MyFragmentStatePager adpter = new MyFragmentStatePager(
                getSupportFragmentManager());
        ColorAnimationView colorAnimationView = (ColorAnimationView) findViewById(R.id.ColorAnimationView);
        ViewPager viewPager = (ViewPager) findViewById(R.id.viewPager);
        //设置adapter
        viewPager.setAdapter(adpter);
        //监听滑动
        colorAnimationView.setmViewPager(viewPager, resource.length);
        colorAnimationView
                .setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
                    @Override
                    public void onPageScrolled(int position,
                            float positionOffset, int positionOffsetPixels) {
                        Log.e("TAG", "onPageScrolled");
                    }

                    @Override
                    public void onPageSelected(int position) {
                        //Button显示或隐藏
                        if (position == 3) {
                            btn_go.setVisibility(View.VISIBLE);
                        } else {
                            btn_go.setVisibility(View.GONE);
                        }
                        Log.e("TAG", "onPageSelected");
                    }

                    @Override
                    public void onPageScrollStateChanged(int state) {
                        Log.e("TAG", "onPageScrollStateChanged");
                    }
                });
    }

    public class MyFragmentStatePager extends FragmentStatePagerAdapter {

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

        @Override
        public Fragment getItem(int position) {
            return new MyFragment(position);
        }

        @Override
        public int getCount() {
            return resource.length;
        }
    }

    @SuppressLint("ValidFragment")
    public class MyFragment extends Fragment {
        private int position;

        public MyFragment(int position) {
            this.position = position;
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            ImageView imageView = new ImageView(getActivity());
            imageView.setImageResource(resource[position]);
            return imageView;
        }
    }
}