【Android】android图片轮播

第一步，先写布局文件

<com.main.util.SlideShowView                 android:id="@+id/slideshowView"                android:layout_width="fill_parent"                android:layout_height="300dp"                android:layout_centerHorizontal="true"                />

第二步，java代码

package com.main.util;import java.util.ArrayList;import java.util.List;import java.util.concurrent.Executors;import java.util.concurrent.ScheduledExecutorService;import java.util.concurrent.TimeUnit;import com.main.R;import android.content.Context;import android.graphics.drawable.Drawable;import android.os.Handler;import android.os.Message;import android.os.Parcelable;import android.support.v4.view.PagerAdapter;import android.support.v4.view.ViewPager;import android.support.v4.view.ViewPager.OnPageChangeListener;import android.util.AttributeSet;import android.view.LayoutInflater;import android.view.View;import android.widget.FrameLayout;import android.widget.ImageView;import android.widget.ImageView.ScaleType;public class SlideShowView extends FrameLayout {//轮播图图片数量    private final static int IMAGE_COUNT = 5;    //自动轮播的时间间隔    private final static int TIME_INTERVAL = 5;    //自动轮播启用开关    private final static boolean isAutoPlay = true;         //自定义轮播图的资源ID    private int[] imagesResIds;    //放轮播图片的ImageView 的list    private List<ImageView> imageViewsList;    //放圆点的View的list    private List<View> dotViewsList;        private ViewPager viewPager;    //当前轮播页    private int currentItem  = 0;    //定时任务    private ScheduledExecutorService scheduledExecutorService;    //Handler    private Handler handler = new Handler(){        @Override        public void handleMessage(Message msg) {            // TODO Auto-generated method stub            super.handleMessage(msg);            viewPager.setCurrentItem(currentItem);        }            };        public SlideShowView(Context context) {        this(context,null);        // TODO Auto-generated constructor stub    }    public SlideShowView(Context context, AttributeSet attrs) {        this(context, attrs, 0);        // TODO Auto-generated constructor stub    }    public SlideShowView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        // TODO Auto-generated constructor stub        initData();        initUI(context);        if(isAutoPlay){            startPlay();        }            }    /**     * 开始轮播图切换     */    private void startPlay(){        scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();        scheduledExecutorService.scheduleAtFixedRate(new SlideShowTask(), 1, 4, TimeUnit.SECONDS);    }    /**     * 停止轮播图切换     */    private void stopPlay(){        scheduledExecutorService.shutdown();    }    /**     * 初始化相关Data     */    private void initData(){        imagesResIds = new int[]{//图片数据                R.drawable.p1,                  R.drawable.p2,        };        imageViewsList = new ArrayList<ImageView>();        dotViewsList = new ArrayList<View>();            }    /**     * 初始化Views等UI     */    private void initUI(Context context){        LayoutInflater.from(context).inflate(R.layout.imageviewpager, this, true);        for(int imageID : imagesResIds){            ImageView view =  new ImageView(context);            view.setImageResource(imageID);            view.setScaleType(ScaleType.FIT_XY);            imageViewsList.add(view);        }        dotViewsList.add(findViewById(R.id.v_dot1));        dotViewsList.add(findViewById(R.id.v_dot2));                viewPager = (ViewPager) findViewById(R.id.viewPager);        viewPager.setFocusable(true);                viewPager.setAdapter(new MyPagerAdapter());        viewPager.setOnPageChangeListener(new MyPageChangeListener());    }        /**     * 填充ViewPager的页面适配器     * @author caizhiming     */    private class MyPagerAdapter  extends PagerAdapter{        @Override        public void destroyItem(View container, int position, Object object) {            // TODO Auto-generated method stub            //((ViewPag.er)container).removeView((View)object);            ((ViewPager)container).removeView(imageViewsList.get(position));        }        @Override        public Object instantiateItem(View container, int position) {            // TODO Auto-generated method stub            ((ViewPager)container).addView(imageViewsList.get(position));            return imageViewsList.get(position);        }        @Override        public int getCount() {            // TODO Auto-generated method stub            return imageViewsList.size();        }        @Override        public boolean isViewFromObject(View arg0, Object arg1) {            // TODO Auto-generated method stub            return arg0 == arg1;        }        @Override        public void restoreState(Parcelable arg0, ClassLoader arg1) {            // TODO Auto-generated method stub        }        @Override        public Parcelable saveState() {            // TODO Auto-generated method stub            return null;        }        @Override        public void startUpdate(View arg0) {            // TODO Auto-generated method stub        }        @Override        public void finishUpdate(View arg0) {            // TODO Auto-generated method stub                    }            }    /**     * ViewPager的监听器     * 当ViewPager中页面的状态发生改变时调用     * @author caizhiming     */    private class MyPageChangeListener implements OnPageChangeListener{        boolean isAutoPlay = false;        @Override        public void onPageScrollStateChanged(int arg0) {            // TODO Auto-generated method stub            switch (arg0) {            case 1:// 手势滑动，空闲中                isAutoPlay = false;                break;            case 2:// 界面切换中                isAutoPlay = true;                break;            case 0:// 滑动结束，即切换完毕或者加载完毕                // 当前为最后一张，此时从右向左滑，则切换到第一张                if (viewPager.getCurrentItem() == viewPager.getAdapter().getCount() - 1 && !isAutoPlay) {                    viewPager.setCurrentItem(0);                }                // 当前为第一张，此时从左向右滑，则切换到最后一张                else if (viewPager.getCurrentItem() == 0 && !isAutoPlay) {                    viewPager.setCurrentItem(viewPager.getAdapter().getCount() - 1);                }                break;        }        }        @Override        public void onPageScrolled(int arg0, float arg1, int arg2) {            // TODO Auto-generated method stub                    }        @Override        public void onPageSelected(int pos) {            // TODO Auto-generated method stub                        currentItem = pos;            for(int i=0;i < dotViewsList.size();i++){                if(i == pos){                    ((View)dotViewsList.get(pos)).setBackgroundResource(R.drawable.dot_black);                }else {                    ((View)dotViewsList.get(i)).setBackgroundResource(R.drawable.dot_white);                }            }        }            }        /**     *执行轮播图切换任务     *@author caizhiming     */    private class SlideShowTask implements Runnable{        @Override        public void run() {            // TODO Auto-generated method stub            synchronized (viewPager) {                currentItem = (currentItem+1)%imageViewsList.size();                handler.obtainMessage().sendToTarget();            }        }            }    /**     * 销毁ImageView资源，回收内存     * @author caizhiming     */    private void destoryBitmaps() {        for (int i = 0; i < IMAGE_COUNT; i++) {            ImageView imageView = imageViewsList.get(i);            Drawable drawable = imageView.getDrawable();            if (drawable != null) {                //解除drawable对view的引用                drawable.setCallback(null);            }        }    }}

更多相关文章

随机推荐