Android ViewPager控件實現圖片輪播

圖片輪播在很多app中需要使用到，下面源碼是通過Android ViewPgaer控件實現圖片輪播。

源碼下載：http://download.csdn.net/detail/zouchao911/8308427

效果圖：

1、MainActivity.java文件代碼：

package com.example.picturecarousel;

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.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.LinearLayout;
import android.widget.ViewFlipper;

public class MainActivity extends Activity {

    private ViewPager view_pager;
    private LinearLayout ll_dotGroup;

    private int imgResIds[] = new int[] { R.drawable.a, R.drawable.b,
            R.drawable.c, R.drawable.d };

    private int curIndex = 0;
    PicsAdapter picsAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        view_pager = (ViewPager) findViewById(R.id.view_pager);
        ll_dotGroup = (LinearLayout) findViewById(R.id.dotgroup);

        picsAdapter = new PicsAdapter(); // 創建適配器
        picsAdapter.setData(imgResIds);
        view_pager.setAdapter(picsAdapter); // 設置適配器

        view_pager.setOnPageChangeListener(new MyPageChangeListener()); //設置頁面切換監聽器

        initPoints(imgResIds.length); // 初始化圖片小圓點
        startAutoScroll(); // 開啓自動播放

    }

    // 初始化圖片輪播的小圓點
    private void initPoints(int count) {
        for (int i = 0; i < count; i++) {

            ImageView iv = new ImageView(this);
            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
                    15, 15);
            params.setMargins(0, 0, 20, 0);
            iv.setLayoutParams(params);

            iv.setImageResource(R.drawable.dot1);
            ll_dotGroup.addView(iv);

        }
        ((ImageView) ll_dotGroup.getChildAt(curIndex))
                .setImageResource(R.drawable.dot2);
    }

    // 自動播放
    private void startAutoScroll() {
        ScheduledExecutorService scheduledExecutorService = Executors
                .newSingleThreadScheduledExecutor();
        // 每隔2秒鐘切換一張圖片
        scheduledExecutorService.scheduleWithFixedDelay(new ViewPagerTask(), 2,
                10, TimeUnit.SECONDS);
    }

    // 切換圖片任務
    private class ViewPagerTask implements Runnable {
        @Override
        public void run() {

            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    int count = picsAdapter.getCount();
                    view_pager.setCurrentItem((curIndex + 1) % count);
                }
            });
        }
    }

    // 定義ViewPager控件頁面切換監聽器
    class MyPageChangeListener implements OnPageChangeListener {

        @Override
        public void onPageScrolled(int position, float positionOffset,
                int positionOffsetPixels) {
        }

        @Override
        public void onPageSelected(int position) {
            ImageView imageView1 = (ImageView) ll_dotGroup.getChildAt(position);
            ImageView imageView2 = (ImageView) ll_dotGroup.getChildAt(curIndex);
            if (imageView1 != null) {
                imageView1.setImageResource(R.drawable.dot2);
            }
            if (imageView2 != null) {
                imageView2.setImageResource(R.drawable.dot1);
            }
            curIndex = position;

        }


        boolean b = false;
        @Override
        public void onPageScrollStateChanged(int state) {
            //這段代碼可不加，主要功能是實現切換到末尾後返回到第一張
            switch (state) {
            case 1:// 手勢滑動
                b = false;
                break;
            case 2:// 界面切換中
                b = true;
                break;
            case 0:// 滑動結束，即切換完畢或者加載完畢
                // 當前爲最後一張，此時從右向左滑，則切換到第一張
                if (view_pager.getCurrentItem() == view_pager.getAdapter()
                        .getCount() - 1 && !b) {
                    view_pager.setCurrentItem(0);
                }
                // 當前爲第一張，此時從左向右滑，則切換到最後一張
                else if (view_pager.getCurrentItem() == 0 && !b) {
                    view_pager.setCurrentItem(view_pager.getAdapter()
                            .getCount() - 1);
                }
                break;

            default:
                break;
            }
        }
    }

    // 定義ViewPager控件適配器
    class PicsAdapter extends PagerAdapter {

        private List<ImageView> views = new ArrayList<ImageView>();

        @Override
        public int getCount() {
            if (views == null) {
                return 0;
            }
            return views.size();
        }

        public void setData(int[] imgResIds) {
            for (int i = 0; i < imgResIds.length; i++) {
                ImageView iv = new ImageView(MainActivity.this);
                ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(
                        ViewGroup.LayoutParams.MATCH_PARENT,
                        ViewGroup.LayoutParams.MATCH_PARENT);
                iv.setLayoutParams(params);
                iv.setScaleType(ScaleType.FIT_XY);
                iv.setImageResource(imgResIds[i]);
                views.add(iv);
            }
        }

        public Object getItem(int position) {
            if (position < getCount())
                return views.get(position);
            return null;
        }

        @Override
        public boolean isViewFromObject(View arg0, Object arg1) {
            return arg0 == arg1;
        }

        @Override
        public void destroyItem(View container, int position, Object object) {

            if (position < views.size())
                ((ViewPager) container).removeView(views.get(position));
        }

        @Override
        public int getItemPosition(Object object) {
            return views.indexOf(object);
        }

        @Override
        public Object instantiateItem(View container, int position) {
            if (position < views.size()) {
                final ImageView imageView = views.get(position);
                ((ViewPager) container).addView(imageView);
                return views.get(position);
            }
            return null;
        }

    }

}

2、主佈局文件activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="150dp"
        android:layout_marginBottom="5dp"
        android:orientation="vertical" >

        <android.support.v4.view.ViewPager
            android:id="@+id/view_pager"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_gravity="center" >
        </android.support.v4.view.ViewPager>

        <LinearLayout
            android:id="@+id/dotgroup"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:gravity="center"
            android:layout_marginBottom="15dp"
            android:orientation="horizontal" >
        </LinearLayout>
    </RelativeLayout>

</RelativeLayout>