viewpager切换的动画效果

1 <android.support.v4.view.ViewPager
2         android:id="@+id/id_viewpager"
3         android:layout_width="match_parent"
4         android:layout_height="match_parent" >
5     </android.support.v4.view.ViewPager>

1         //第一个参数true child倒叙 false child顺序
2         //第二个参数就是实现ViewPager.PageTransformer的接口的类
3         mViewPager.setPageTransformer(arg0, arg1);

 1 import android.view.View;
 2 import android.support.v4.view.ViewPager;
 3 
 4 public class DepthPageTransformer implements ViewPager.PageTransformer {
 5 
 6     private static final float MIN_SCALE = 0.75f;
 7     public void transformPage(View view, float position) {
 8         int pageWidth = view.getWidth();
 9 
10         if (position < -1) { // [-Infinity,-1)
11             // This page is way off-screen to the left.
12             view.setAlpha(0);
13 
14         } else if (position <= 0) { // [-1,0]
15             // Use the default slide transition when moving to the left page
16             view.setAlpha(1);
17             view.setTranslationX(0);
18             view.setScaleX(1);
19             view.setScaleY(1);
20 
21         } else if (position <= 1) { // (0,1]
22             // Fade the page out.
23             view.setAlpha(1 - position);
24 
25             // Counteract the default slide transition
26             view.setTranslationX(pageWidth * -position);
27 
28             // Scale the page down (between MIN_SCALE and 1)
29             float scaleFactor = MIN_SCALE + (1 - MIN_SCALE)
30                     * (1 - Math.abs(position));
31             view.setScaleX(scaleFactor);
32             view.setScaleY(scaleFactor);
33 
34         } else { // (1,+Infinity]
35             // This page is way off-screen to the right.
36             view.setAlpha(0);
37         }
38     }
39 }

1 mViewPager.setPageTransformer(true, new DepthPageTransformer());

 1 import android.view.View;
 2 import android.support.v4.view.ViewPager;
 3 
 4 public class ZoomOutPageTransformer implements ViewPager.PageTransformer {
 5     private static final float MIN_SCALE = 0.85f;
 6     private static final float MIN_ALPHA = 0.5f;
 7 
 8     public void transformPage(View view, float position) {
 9         int pageWidth = view.getWidth();
10         int pageHeight = view.getHeight();
11 
12         Log.e("TAG", view + " , " + position + "");
13 
14         if (position < -1) { // [-Infinity,-1)
15                                 // This page is way off-screen to the left.
16             view.setAlpha(0);
17 
18         } else if (position <= 1) // a页滑动至b页 ； a页从 0.0 -1 ；b页从1 ~ 0.0
19         { // [-1,1]
20             // Modify the default slide transition to shrink the page as well
21             float scaleFactor = Math.max(MIN_SCALE, 1 - Math.abs(position));
22             float vertMargin = pageHeight * (1 - scaleFactor) / 2;
23             float horzMargin = pageWidth * (1 - scaleFactor) / 2;
24             if (position < 0) {
25                 view.setTranslationX(horzMargin - vertMargin / 2);
26             } else {
27                 view.setTranslationX(-horzMargin + vertMargin / 2);
28             }
29 
30             // Scale the page down (between MIN_SCALE and 1)
31             view.setScaleX(scaleFactor);
32             view.setScaleY(scaleFactor);
33 
34             // Fade the page relative to its size.
35             view.setAlpha(MIN_ALPHA + (scaleFactor - MIN_SCALE)
36                     / (1 - MIN_SCALE) * (1 - MIN_ALPHA));
37 
38         } else { // (1,+Infinity]
39                     // This page is way off-screen to the right.
40             view.setAlpha(0);
41         }
42     }
43 }

 1 /**
 2      * Set a {@link PageTransformer} that will be called for each attached page whenever
 3      * the scroll position is changed. This allows the application to apply custom property
 4      * transformations to each page, overriding the default sliding look and feel.
 5      *
 6      * <p><em>Note:</em> Prior to Android 3.0 the property animation APIs did not exist.
 7      * As a result, setting a PageTransformer prior to Android 3.0 (API 11) will have no effect.</p>
 8      *
 9      * @param reverseDrawingOrder true if the supplied PageTransformer requires page views
10      *                            to be drawn from last to first instead of first to last.
11      * @param transformer PageTransformer that will modify each page‘s animation properties
12      */
13     public void setPageTransformer(boolean reverseDrawingOrder, PageTransformer transformer) {
14         if (Build.VERSION.SDK_INT >= 11) {
15             final boolean hasTransformer = transformer != null;
16             final boolean needsPopulate = hasTransformer != (mPageTransformer != null);
17             mPageTransformer = transformer;
18             setChildrenDrawingOrderEnabledCompat(hasTransformer);
19             if (hasTransformer) {
20                 mDrawingOrder = reverseDrawingOrder ? DRAW_ORDER_REVERSE : DRAW_ORDER_FORWARD;
21             } else {
22                 mDrawingOrder = DRAW_ORDER_DEFAULT;
23             }
24             if (needsPopulate) populate();
25         }
26     }