Android-ViewPager( 切换动画实现 , 兼容性实现)

1.回顾

  上篇学习了使用 Android Studio 实现 安卓属性动画的例子;

2.重点

  (1)ViewPager实现

  (2)添加动画切换效果

  (3)兼容性实现

3.ViewPager实现

   ViewPager实现 三种实现方式,前面已经学习过了, 具体请看:

   Android-ViewPager（PagerAdapter 实现）

   http://blog.csdn.net/lablenet/article/details/47958901

4.添加切换动画

  4.1 通过调用 setPageTransformer(boolean,pageTransformer)

       参数1 ,为 boolean 类型 , 第二个 为 pageTransformer 实现类;

  4.2实现

      Android 官方提供了 两种 切换 方式  即 pageTransformer 的 两种实现:

     (1) DepthPageTransformer

package cn.labelnet.util;import android.annotation.SuppressLint;import android.support.v4.view.ViewPager;import android.view.View;public class DepthPageTransformer implements ViewPager.PageTransformer {    private static final float MIN_SCALE = 0.75f;        @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) ZoomOutPageTransformer

package cn.labelnet.util;import android.annotation.SuppressLint;import android.support.v4.view.ViewPager;import android.view.View;public class ZoomOutPageTransformer implements ViewPager.PageTransformer {    private static final float MIN_SCALE = 0.85f;    private static final float MIN_ALPHA = 0.5f;        @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);        }    }}

   4.3 兼容性

       Andorid 动画 在 Android3.0 版本 (api 11) 以上 才能使用 动画属性 ,所以 想让 兼容 低版本 就要 引用 第三方 jar包-nineoldandroids.jar;

      jar包 下载 : 见 demo下载!

  4.4 使用 兼容包实现 另一个自定义动画

   模仿着上面的实现

package cn.labelnet.util;import com.nineoldandroids.view.ViewHelper;import android.annotation.SuppressLint;import android.support.v4.view.ViewPager.PageTransformer;import android.view.View;public class RoatePageTransformer implements PageTransformer {   private static final float MIN_ROATE =20f;   //旋转角度的变化   private float roate;   @Overridepublic void transformPage(View view, float position) {        int pageWidth = view.getWidth();        if (position < -1) { // [-Infinity,-1)            // This page is way off-screen to the left.            ViewHelper.setRotation(view, 0);        } else if (position <= 0) { // [-1,0]            // Use the default slide transition when moving to the left page                roate=MIN_ROATE*position;                ViewHelper.setPivotX(view, pageWidth/2);        ViewHelper.setPivotY(view, view.getMeasuredHeight());                ViewHelper.setRotation(view, roate);                 } else if (position <= 1) { // (0,1]        roate=MIN_ROATE*position;                ViewHelper.setPivotX(view, pageWidth/2);        ViewHelper.setPivotY(view, view.getMeasuredHeight());                ViewHelper.setRotation(view, roate);        } else { // (1,+Infinity]            ViewHelper.setRotation(view, 0);        }}  }

5.demo 免积分下载 

  http://download.csdn.net/detail/lablenet/9110343