Android ViewPager控件实现图片轮播

图片轮播在很多app中需要使用到，下面源码是通过Android ViewPgaer控件实现图片轮播。

源码下载：http://download.csdn.net/detail/zouchao911/8308427

效果图：



1、MainActivity.java文件代码：

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(); // 创建适配器
picsAdapter.setData(imgResIds);
view_pager.setAdapter(picsAdapter); // 设置适配器

view_pager.setOnPageChangeListener(new MyPageChangeListener()); //设置页面切换监听器

initPoints(imgResIds.length); // 初始化图片小圆点
startAutoScroll(); // 开启自动播放

}

// 初始化图片轮播的小圆点
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);
}

// 自动播放
private void startAutoScroll() {
ScheduledExecutorService scheduledExecutorService = Executors
.newSingleThreadScheduledExecutor();
// 每隔2秒钟切换一张图片
scheduledExecutorService.scheduleWithFixedDelay(new ViewPagerTask(), 2,
10, TimeUnit.SECONDS);
}

// 切换图片任务
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);
}
});
}
}

// 定义ViewPager控件页面切换监听器
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) {
//这段代码可不加，主要功能是实现切换到末尾后返回到第一张
switch (state) {
case 1:// 手势滑动
b = false;
break;
case 2:// 界面切换中
b = 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 (view_pager.getCurrentItem() == view_pager.getAdapter()
.getCount() - 1 && !b) {
view_pager.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 (view_pager.getCurrentItem() == 0 && !b) {
view_pager.setCurrentItem(view_pager.getAdapter()
.getCount() - 1);
}
break;

default:
break;
}
}
}

// 定义ViewPager控件适配器
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、主布局文件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>