android 图片滚动可以自动切换

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package com.example.viewpager;import java.util.ArrayList;import java.util.List;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.support.v4.view.ViewPager;import android.support.v4.view.ViewPager.OnPageChangeListener;import android.view.LayoutInflater;import android.view.View;import android.widget.ImageView;public class Guide extends Activity implements OnPageChangeListener {    private ViewPager vp;    private ViewPagerAdapter vpa;    private List<View> views;//背景图片    private ImageView[] dots;//选中点    private int[] ids = { R.id.iv1, R.id.iv2, R.id.iv3 };//图片控件显示点的    private int currentItem = 0;//当前显示图片    private ScheduledExecutorService scheduledExecutorService;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.guide);        initView();        initDots();    }    private Handler handler = new Handler() {        public void handleMessage(android.os.Message msg) {            vp.setCurrentItem(currentItem);// 切换当前显示的图片        };    };    private void initView() {        LayoutInflater lInflater = LayoutInflater.from(this);        views = new ArrayList<View>();        views.add(lInflater.inflate(R.layout.one, null));        views.add(lInflater.inflate(R.layout.two, null));        views.add(lInflater.inflate(R.layout.three, null));        vpa = new ViewPagerAdapter(views, this);        vp = (ViewPager) findViewById(R.id.viewpager);        vp.setAdapter(vpa);        vp.setOnPageChangeListener(this);    }    private void initDots() {        dots = new ImageView[views.size()];        for (int i = 0; i < views.size(); i++) {            dots[i] = (ImageView) findViewById(ids[i]);        }    }    private class ScrollTask implements Runnable {        public void run() {            synchronized (vp) {                System.out.println("currentItem: " + currentItem);                currentItem = (currentItem + 1) % views.size();                handler.obtainMessage().sendToTarget(); // 通过Handler切换图片            }        }    }    @Override    protected void onStart() {        scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();        // 当Activity显示出来后，每两秒钟切换一次图片显示        scheduledExecutorService.scheduleAtFixedRate(new ScrollTask(), 1, 2,                TimeUnit.SECONDS);        super.onStart();    }    @Override    protected void onStop() {        // 当Activity不可见的时候停止切换        scheduledExecutorService.shutdown();        super.onStop();    }    @Override    public void onPageScrollStateChanged(int arg0) {    }    @Override    public void onPageScrolled(int arg0, float arg1, int arg2) {    }    @Override    public void onPageSelected(int arg0) {        currentItem = arg0;        for (int i = 0; i < ids.length; i++) {            if (arg0 == i) {                dots[i].setImageResource(R.drawable.point);            } else {                dots[i].setImageResource(R.drawable.point_select);            }        }    }}

viewPager适配器：

package com.example.viewpager;import java.util.List;import android.content.Context;import android.support.v4.view.PagerAdapter;import android.support.v4.view.ViewPager;import android.view.View;public class ViewPagerAdapter extends PagerAdapter {    private List<View> views;    private Context context;    public ViewPagerAdapter(List<View> views, Context context) {        super();        this.views = views;        this.context = context;    }    @Override    public void destroyItem(View container, int position, Object object) {        ((ViewPager)container).removeView(views.get(position));    }    @Override    public Object instantiateItem(View container, int position) {        ((ViewPager)container).addView(views.get(position));        return views.get(position);    }    @Override    public int getCount() {        return views.size();    }    @Override    public boolean isViewFromObject(View arg0, Object arg1) {        return arg0==arg1;    }}

guide.xml:

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical" >    <android.support.v4.view.ViewPager        android:id="@+id/viewpager"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:background="#00000000" >    </android.support.v4.view.ViewPager>    <LinearLayout        android:id="@+id/ll"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:layout_alignParentBottom="true"        android:gravity="center_horizontal"        android:orientation="horizontal" >        <ImageView            android:id="@+id/iv1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:background="@drawable/point_select" >        </ImageView>        <ImageView            android:id="@+id/iv2"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:background="@drawable/point" >        </ImageView>        <ImageView            android:id="@+id/iv3"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:background="@drawable/point" >        </ImageView>    </LinearLayout></RelativeLayout>

one.xml:

<?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:id="@+id/imageView1"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:src="@drawable/guide_1" /></LinearLayout>

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