Android项目实战（四）：ViewPager切换动画（3.0版本以上有效果）

 1 public class ZoomOutPageTransformer implements ViewPager.PageTransformer {
 2     private static final float MIN_SCALE = 0.85f;
 3     private static final float MIN_ALPHA = 0.5f;
 4 
 5     public void transformPage(View view, float position) {
 6         int pageWidth = view.getWidth();
 7         int pageHeight = view.getHeight();
 8 
 9         if (position < -1) { // [-Infinity,-1)
10             // This page is way off-screen to the left.
11             view.setAlpha(0);
12 
13         } else if (position <= 1) { // [-1,1]
14             // Modify the default slide transition to shrink the page as well
15             float scaleFactor = Math.max(MIN_SCALE, 1 - Math.abs(position));
16             float vertMargin = pageHeight * (1 - scaleFactor) / 2;
17             float horzMargin = pageWidth * (1 - scaleFactor) / 2;
18             if (position < 0) {
19                 view.setTranslationX(horzMargin - vertMargin / 2);
20             } else {
21                 view.setTranslationX(-horzMargin + vertMargin / 2);
22             }
23 
24             // Scale the page down (between MIN_SCALE and 1)
25             view.setScaleX(scaleFactor);
26             view.setScaleY(scaleFactor);
27 
28             // Fade the page relative to its size.
29             view.setAlpha(MIN_ALPHA +
30                     (scaleFactor - MIN_SCALE) /
31                     (1 - MIN_SCALE) * (1 - MIN_ALPHA));
32 
33         } else { // (1,+Infinity]
34             // This page is way off-screen to the right.
35             view.setAlpha(0);
36         }
37     }
38 }

 1 public class DepthPageTransformer implements ViewPager.PageTransformer {
 2     private static final float MIN_SCALE = 0.75f;
 3 
 4     public void transformPage(View view, float position) {
 5         int pageWidth = view.getWidth();
 6 
 7         if (position < -1) { // [-Infinity,-1)
 8             // This page is way off-screen to the left.
 9             view.setAlpha(0);
10 
11         } else if (position <= 0) { // [-1,0]
12             // Use the default slide transition when moving to the left page
13             view.setAlpha(1);
14             view.setTranslationX(0);
15             view.setScaleX(1);
16             view.setScaleY(1);
17 
18         } else if (position <= 1) { // (0,1]
19             // Fade the page out.
20             view.setAlpha(1 - position);
21 
22             // Counteract the default slide transition
23             view.setTranslationX(pageWidth * -position);
24 
25             // Scale the page down (between MIN_SCALE and 1)
26             float scaleFactor = MIN_SCALE
27                     + (1 - MIN_SCALE) * (1 - Math.abs(position));
28             view.setScaleX(scaleFactor);
29             view.setScaleY(scaleFactor);
30 
31         } else { // (1,+Infinity]
32             // This page is way off-screen to the right.
33             view.setAlpha(0);
34         }
35     }
36 }