ViewPager引导页效果实例源码

       首先大家先找到本地的sdk，然后找到Google提供的API，具体查找方法如下：sdk——>docs——>index.html——>develop——>training——>左边的目录下找到Build Apps with Graphics & Animation——>Adding Animation——>Using ViewPager for Screen Slides，在这里我们要用到两个接口DepthPageTransformer和ZoomOutPageTransformer，这是两个动画效果，大家可以根据需求选择相应的接口。为什么我没有直接把自己实现的代码粘贴出来，因为我建议大家没事的时候就在学一学，看一看Google提供的API。我也是最近才开始发现学会了对自己平时的开发有很大的帮助，下面我就把我的源码给大家分享一下把，布局我就不说了，只有一个ViewPager。

    1、自定义接口DepthPageTransformer实现ViewPager.PageTransformer，也可以把API的全部复制粘贴。

package com.app.myviewpagercartoon;

import android.view.View;
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.os.Build;
import android.support.v4.view.ViewPager;

@TargetApi(Build.VERSION_CODES.HONEYCOMB) @SuppressLint("NewApi") public class DepthPageTransformer implements ViewPager.PageTransformer {
    private static final float MIN_SCALE = 0.75f;

    @TargetApi(Build.VERSION_CODES.HONEYCOMB) @SuppressLint("NewApi") 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);
        }
    }
}

2、自定义ZoomOutPageTransformer 实现ViewPager.PageTransformer，也可以把API的全部复制粘贴。

package com.app.myviewpagercartoon;

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.os.Build;
import android.support.v4.view.ViewPager;
import android.view.View;

@TargetApi(Build.VERSION_CODES.HONEYCOMB) @SuppressLint("NewApi") public class ZoomOutPageTransformer implements ViewPager.PageTransformer {
    private static final float MIN_SCALE = 0.85f;
    private static final float MIN_ALPHA = 0.5f;
   
    @TargetApi(Build.VERSION_CODES.HONEYCOMB) @SuppressLint("NewApi") public void transformPage(View view, float position) {
        int pageWidth = view.getWidth();
        int pageHeight = view.getHeight();

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

        } else if (position <= 1) { // [-1,1]
            // Modify the default slide transition to shrink the page as well
            float scaleFactor = Math.max(MIN_SCALE, 1 - Math.abs(position));
            float vertMargin = pageHeight * (1 - scaleFactor) / 2;
            float horzMargin = pageWidth * (1 - scaleFactor) / 2;
            if (position < 0) {
                view.setTranslationX(horzMargin - vertMargin / 2);
            } else {
                view.setTranslationX(-horzMargin + vertMargin / 2);
            }

            // Scale the page down (between MIN_SCALE and 1)
            view.setScaleX(scaleFactor);
            view.setScaleY(scaleFactor);

            // Fade the page relative to its size.
            view.setAlpha(MIN_ALPHA +
                    (scaleFactor - MIN_SCALE) /
                    (1 - MIN_SCALE) * (1 - MIN_ALPHA));

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

    3、实现MainActivity类的代码

package com.app.myviewpagercartoon;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;

public class MainActivity extends Activity {

    private ViewPager viewPager;
    //图片太大卡，我没有对图片进行处理，大家可以处理一下图片
    private int[] imags = new int[] { R.drawable.guide_image1,
            R.drawable.guide_image2, R.drawable.guide_image3 };
    private List<ImageView> list = new ArrayList<ImageView>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        viewPager = (ViewPager) findViewById(R.id.viewPager);
        //添加两种动画效果，3.0以上有效
        //viewPager.setPageTransformer(true, new ZoomOutPageTransformer());
        viewPager.setPageTransformer(true, new DepthPageTransformer());
        viewPager.setAdapter(new PagerAdapter() {

            @Override
            public Object instantiateItem(ViewGroup container, int position) {
                ImageView imageView = new ImageView(MainActivity.this);
                imageView.setImageResource(imags[position]);
                imageView.setScaleType(ScaleType.CENTER_CROP);
                container.addView(imageView);
                list.add(imageView);
                return imageView;
            }

            @Override
            public void destroyItem(ViewGroup container, int position,
                    Object object) {
            
                container.removeView(list.get(position));
            }

            @Override
            public boolean isViewFromObject(View arg0, Object arg1) {

                return arg0 == arg1;
            }

            @Override
            public int getCount() {

                return imags.length;
            }
        });
    }

}

      附上效果图：