android ViewPager实现滑动翻页效果实例代码

import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.View;


public class ReadViewPager extends ViewPager
{
  public ReadViewPager(Context context)
  {
    super(context);
  }

  public ReadViewPager(Context context, AttributeSet attrs)
  {
    super(context, attrs);
    setAnima();
  }

  public void setAnima()
  {
    setPageTransformer(true, new PageTransformer()
    {
      private static final float MIN_SCALE = 0.75f;

      @Override
      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 <= 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.setAlpha(1);
          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);
        }
      }

    });
  }
}

setPageTransformer(true, new PageTransformer() {
      private static final float MIN_SCALE = 0.75f;

      @Override
      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 <= 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.setAlpha(1);
          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);
        }


      }
    });