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Android ViewPager怎么实现每隔两秒自动切换图片功能

发表于:2024-11-23 作者:千家信息网编辑
千家信息网最后更新 2024年11月23日,这篇文章主要介绍"Android ViewPager怎么实现每隔两秒自动切换图片功能",在日常操作中,相信很多人在Android ViewPager怎么实现每隔两秒自动切换图片功能问题上存在疑惑,小编
千家信息网最后更新 2024年11月23日Android ViewPager怎么实现每隔两秒自动切换图片功能

这篇文章主要介绍"Android ViewPager怎么实现每隔两秒自动切换图片功能",在日常操作中,相信很多人在Android ViewPager怎么实现每隔两秒自动切换图片功能问题上存在疑惑,小编查阅了各式资料,整理出简单好用的操作方法,希望对大家解答"Android ViewPager怎么实现每隔两秒自动切换图片功能"的疑惑有所帮助!接下来,请跟着小编一起来学习吧!

布局代码:

                                                                                                                                                    

正常的shape图形dot_normal.xml:

        

获取焦点的shape图形 dot_focused.xml

        

具体实现代码:

import java.util.ArrayList;import java.util.concurrent.Executors;import java.util.concurrent.ScheduledExecutorService;import java.util.concurrent.TimeUnit;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.support.v4.view.PagerAdapter;import android.support.v4.view.ViewPager;import android.support.v4.view.ViewPager.OnPageChangeListener;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import android.widget.TextView;public class MainActivity extends Activity {    private int imageIds[];    private String[] titles;    private ArrayList images;    private ArrayList dots;    private TextView title;    private ViewPager mViewPager;    private ViewPagerAdapter adapter;    private int oldPosition = 0;//记录上一次点的位置    private int currentItem; //当前页面    private ScheduledExecutorService scheduledExecutorService;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //图片ID        imageIds = new int[]{            R.drawable.a,            R.drawable.b,            R.drawable.c,            R.drawable.d,            R.drawable.e        };        //图片标题        titles = new String[]{            "巩俐不低俗,我就不能低俗",            "扑树又回来啦!再唱经典老歌引万人大合唱",            "揭秘北京电影如何升级",            "乐视网TV版大派送",            "热血屌丝的反杀"        };        //显示的图片        images = new ArrayList();        for(int i =0; i < imageIds.length; i++){            ImageView imageView = new ImageView(this);            imageView.setBackgroundResource(imageIds[i]);            images.add(imageView);        }        //显示的点        dots = new ArrayList();        dots.add(findViewById(R.id.dot_0));        dots.add(findViewById(R.id.dot_1));        dots.add(findViewById(R.id.dot_2));        dots.add(findViewById(R.id.dot_3));        dots.add(findViewById(R.id.dot_4));        title = (TextView) findViewById(R.id.title);        title.setText(titles[0]);        mViewPager = (ViewPager) findViewById(R.id.vp);        adapter = new ViewPagerAdapter();        mViewPager.setAdapter(adapter);        mViewPager.setOnPageChangeListener(new OnPageChangeListener() {            @Override            public void onPageSelected(int position) {                // TODO Auto-generated method stub                title.setText(titles[position]);                dots.get(oldPosition).setBackgroundResource(R.drawable.dot_normal);                dots.get(position).setBackgroundResource(R.drawable.dot_focused);                oldPosition = position;                currentItem = position;            }            @Override            public void onPageScrolled(int arg0, float arg1, int arg2) {                // TODO Auto-generated method stub            }            @Override            public void onPageScrollStateChanged(int arg0) {                // TODO Auto-generated method stub            }        });    }    private class ViewPagerAdapter extends PagerAdapter {        @Override        public int getCount() {            // TODO Auto-generated method stub            return images.size();        }        //是否是同一张图片        @Override        public boolean isViewFromObject(View arg0, Object arg1) {            // TODO Auto-generated method stub            return arg0 == arg1;        }        @Override        public void destroyItem(ViewGroup view, int position, Object object) {            // TODO Auto-generated method stub//            super.destroyItem(container, position, object);//            view.removeViewAt(position);            view.removeView(images.get(position));        }        @Override        public Object instantiateItem(ViewGroup view, int position) {            // TODO Auto-generated method stub            view.addView(images.get(position));            return images.get(position);        }    }    @Override    protected void onStart() {        // TODO Auto-generated method stub        super.onStart();        scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();        //每隔2秒钟切换一张图片        scheduledExecutorService.scheduleWithFixedDelay(new ViewPagerTask(), 2, 2, TimeUnit.SECONDS);    }    //切换图片    private class ViewPagerTask implements Runnable {        @Override        public void run() {            // TODO Auto-generated method stub            currentItem = (currentItem +1) % imageIds.length;            //更新界面//            handler.sendEmptyMessage(0);            handler.obtainMessage().sendToTarget();        }    }    private Handler handler = new Handler(){        @Override        public void handleMessage(Message msg) {            // TODO Auto-generated method stub            //设置当前页面            mViewPager.setCurrentItem(currentItem);        }    };    @Override    protected void onStop() {        // TODO Auto-generated method stub        super.onStop();    }}

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