Android开发之使用ViewPager实现图片左右滑动切换效果

<?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"  >  <ImageView    android:layout_width="match_parent"    android:layout_height="match_parent"    android:scaleType="centerCrop"    android:src="@mipmap/view1"/></LinearLayout>

<?xml version="1.0" encoding="UTF-8"?><RelativeLayout android:orientation="vertical"android:layout_height="match_parent"android:layout_width="match_parent"xmlns:android="http://schemas.android.com/apk/res/android"><!-- 切换卡 --><android.support.v4.view.ViewPager  android:layout_height="wrap_content"  android:layout_width="match_parent"  android:id="@+id/viewPager"></android.support.v4.view.ViewPager><!-- 点点 --><LinearLayout  android:orientation="horizontal"  android:layout_height="wrap_content"  android:layout_width="fill_parent"  android:id="@+id/viewGroup"  android:layout_alignParentBottom="true"  android:gravity="center_horizontal"  android:layout_marginBottom="40dp"></LinearLayout></RelativeLayout>

package com.yztc.lx.homework;import android.app.Activity;import android.os.Bundle;import android.support.v4.view.PagerAdapter;import android.support.v4.view.ViewPager;import android.view.LayoutInflater;import android.view.ViewGroup.LayoutParams;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import java.util.ArrayList;import java.util.List;/** * Created by Lx on 2016/8/6. */public class Layout1Activity extends Activity {  private ViewPager viewPager;  private PagerAdapter adapter;  private List<View> viewPages = new ArrayList<>();  //包裹点点的LinearLayout  private ViewGroup group;  private ImageView imageView;  //定义一个ImageVIew数组，来存放生成的小园点  private ImageView[] imageViews;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.layout1);    initView();    initPageAdapter();    initPointer();    initEvent();  }  //为控件绑定事件,绑定适配器  private void initEvent() {    viewPager.setAdapter(adapter);    viewPager.addOnPageChangeListener(new GuidePageChangeListener());  }  //初始化ViewPager  private void initPageAdapter() {    /**     * 对于这几个想要动态载入的page页面，使用LayoutInflater.inflate()来找到其布局文件，并实例化为View对象     */    LayoutInflater inflater = LayoutInflater.from(this);    View page1 = inflater.inflate(R.layout.page1, null);    View page2 = inflater.inflate(R.layout.page2, null);    View page3 = inflater.inflate(R.layout.page3, null);    //添加到集合中    viewPages.add(page1);    viewPages.add(page2);    viewPages.add(page3);    adapter = new PagerAdapter() {      //获取当前界面个数      @Override      public int getCount() {        return viewPages.size();      }      //判断是否由对象生成页面      @Override      public boolean isViewFromObject(View view, Object object) {        return view == object;      }      @Override      public void destroyItem(ViewGroup container, int position, Object object) {        container.removeView(viewPages.get(position));      }      //返回一个对象，这个对象表明了PagerAdapter适配器选择哪个对象放在当前的ViewPager中      @Override      public Object instantiateItem(ViewGroup container, int position) {        View view = viewPages.get(position);        container.addView(view);        return view;      }    };  }  //绑定控件  private void initView() {    viewPager = (ViewPager) findViewById(R.id.viewPager);    group = (ViewGroup) findViewById(R.id.viewGroup);  }  //初始化下面的小圆点的方法  private void initPointer() {    //有多少个界面就new多长的数组    imageViews = new ImageView[viewPages.size()];    for (int i = 0; i < imageViews.length; i++) {      imageView = new ImageView(this);      //设置控件的宽高      imageView.setLayoutParams(new LayoutParams(25, 25));      //设置控件的padding属性      imageView.setPadding(20, 0, 20, 0);      imageViews[i] = imageView;      //初始化第一个page页面的图片的原点为选中状态      if (i == 0) {        //表示当前图片        imageViews[i].setBackgroundResource(R.mipmap.page_indicator_focused);        /**         * 在java代码中动态生成ImageView的时候         * 要设置其BackgroundResource属性才有效         * 设置ImageResource属性无效         */      } else {        imageViews[i].setBackgroundResource(R.mipmap.page_indicator_unfocused);      }      group.addView(imageViews[i]);    }  }  //ViewPager的onPageChangeListener监听事件，当ViewPager的page页发生变化的时候调用  public class GuidePageChangeListener implements ViewPager.OnPageChangeListener {    @Override    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {    }    //页面滑动完成后执行    @Override    public void onPageSelected(int position) {      //判断当前是在那个page，就把对应下标的ImageView原点设置为选中状态的图片      for (int i = 0; i < imageViews.length; i++) {        imageViews[position].setBackgroundResource(R.mipmap.page_indicator_focused);        if (position != i) {          imageViews[i].setBackgroundResource(R.mipmap.page_indicator_unfocused);        }      }    }    //监听页面的状态，0--静止 1--滑动  2--滑动完成    @Override    public void onPageScrollStateChanged(int state) {    }  }}