Viewpager切换效果

	
import android.support.v4.view.ViewPager.PageTransformer;
import android.view.View;

public class DepthPageTransformer implements PageTransformer {
    private static float MIN_SCALE = 0.75f;
                          
    @Override
    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);
                          
        }
    }                        
}

import android.support.v4.view.ViewPager.PageTransformer;
import android.view.View;

public class ZoomOutPageTransformer implements PageTransformer {
    private static float MIN_SCALE = 0.85f;
                  
    private static float MIN_ALPHA = 0.5f;
                  
    @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 <= 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);
        }
    }
}