博客

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>