Android使用手势实现翻页效果

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical">
 <!-- 定义ViewFlipper组件 -->
 <ViewFlipper
  android:id="@+id/flipper"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content" />
</LinearLayout>

package com.fukaimei.gestureflip;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ImageView;
import android.widget.ViewFlipper;

public class MainActivity extends AppCompatActivity implements GestureDetector.OnGestureListener {

 // ViewFlipper实例
 ViewFlipper flipper;
 // 定义手势检测实例
 GestureDetector detector;
 // 定义一个动画数组，用于为ViewFlipper指定切换动画效果
 Animation[] animations = new Animation[4];
 // 定义手势动作亮点之间的最小距离
 final int FLIP_DISTANCE = 50;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  // 创建手势检测器
  detector = new GestureDetector(this, this);
  // 获得ViewFlipper实例
  flipper = (ViewFlipper) this.findViewById(R.id.flipper);
  // 为ViewFlipper添加8个ImageView组件
  flipper.addView(addImageView(R.drawable.img01));
  flipper.addView(addImageView(R.drawable.img02));
  flipper.addView(addImageView(R.drawable.img03));
  flipper.addView(addImageView(R.drawable.img04));
  flipper.addView(addImageView(R.drawable.img05));
  flipper.addView(addImageView(R.drawable.img06));
  flipper.addView(addImageView(R.drawable.img07));
  flipper.addView(addImageView(R.drawable.img08));
  // 初始化Animation数组
  animations[0] = AnimationUtils.loadAnimation(this, R.anim.left_in);
  animations[1] = AnimationUtils.loadAnimation(this, R.anim.left_out);
  animations[2] = AnimationUtils.loadAnimation(this, R.anim.right_in);
  animations[3] = AnimationUtils.loadAnimation(this, R.anim.right_out);
 }

 // 定义添加ImageView的工具方法
 private View addImageView(int resId) {
  ImageView imageView = new ImageView(this);
  imageView.setImageResource(resId);
  imageView.setScaleType(ImageView.ScaleType.CENTER);
  return imageView;
 }

 @Override
 public boolean onTouchEvent(MotionEvent event) {
  // 将该Activity上的触碰事件交给GestureDetector处理
  return detector.onTouchEvent(event);
 }

 @Override
 public boolean onDown(MotionEvent e) {
  return false;
 }

 @Override
 public void onShowPress(MotionEvent e) {

 }

 @Override
 public boolean onSingleTapUp(MotionEvent e) {
  return false;
 }

 @Override
 public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
  return false;
 }

 @Override
 public void onLongPress(MotionEvent e) {

 }

 @Override
 public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
  // 如果第一个触点事件的X坐标大于第二个触点事件的X坐标超过FLIP_DISTANCE
  // 也就是手势从右向左滑
  if (e1.getX() - e2.getX() > FLIP_DISTANCE) {
   // 为flipper设置切换的动画效果
   flipper.setInAnimation(animations[0]);
   flipper.setOutAnimation(animations[1]);
   flipper.showPrevious();
   return true;
  }
  // 如果第二个触点事件的X坐标大于第一个触点事件的X坐标超过FLIP_DISTANCE
  // 也就是手势从右向左滑
  else if (e2.getX() - e1.getX() > FLIP_DISTANCE) {
   // 为flipper设置切换的动画效果
   flipper.setInAnimation(animations[2]);
   flipper.setOutAnimation(animations[3]);
   flipper.showNext();
   return true;
  }
  return false;
 }
}

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
 <translate
  android:duration="500"
  android:fromXDelta="100%p"
  android:toXDelta="0" />
 <alpha
  android:duration="500"
  android:fromAlpha="0.1"
  android:toAlpha="1.0" />
</set> 

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
 <translate
  android:duration="500"
  android:fromXDelta="0"
  android:toXDelta="-100%p" />
 <alpha
  android:duration="500"
  android:fromAlpha="0.1"
  android:toAlpha="1.0" />
</set> 

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
 <translate
  android:duration="500"
  android:fromXDelta="-100%p"
  android:toXDelta="0" />
 <alpha
  android:duration="500"
  android:fromAlpha="0.1"
  android:toAlpha="1.0" />
</set>

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
 <translate
  android:duration="500"
  android:fromXDelta="0"
  android:toXDelta="100%p" />
 <alpha
  android:duration="500"
  android:fromAlpha="0.1"
  android:toAlpha="1.0" />
</set>