android viewPager网络加载图片无限自动轮播

欢迎大家吐槽





，有什么问题或bug，我们一起探讨。。。。

先看效果，还有demo自己可以看。。

public class MainActivity extends Activity {

private ViewPager mViewPager;
// 记录当前的页数
private int mCount = 0;
// 开始
public static final int START = -1;
// 停止
public static final int STOP = -2;
// 更新
public static final int UPDATE = -3;
// 接受传过来的当前页面数
public static final int RECORD = -4;
private List<ImageView> mList;
private MyPagerAdapter mAdapter;
private List<String> urlList;
private ImageView dot1, dot2, dot3, dot0;
private ImageView[] dots = new ImageView[4];
private Handler handler = new Handler() {
public void handleMessage(android.os.Message msg) {

switch (msg.what) {
case START:
handler.sendEmptyMessageDelayed(UPDATE, 3000);
break;
case STOP:
handler.removeMessages(UPDATE);
break;
case UPDATE:
mCount++;
mViewPager.setCurrentItem(mCount);
break;
case RECORD:
mCount = msg.arg1;
break;

default:
break;
}

}
};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
init();
setListener();
mAdapter = new MyPagerAdapter(mList);
mViewPager.setAdapter(mAdapter);
int i = Integer.MAX_VALUE / 2 % mList.size();
// 默认在中间，让用户看不到边界
mViewPager.setCurrentItem(Integer.MAX_VALUE / 2 - i);
handler.sendEmptyMessage(START);
}

private void init() {
// TODO Auto-generated method stub
urlList = new ArrayList<String>();
mList = new ArrayList<ImageView>();
urlList.add("http://tupian.enterdesk.com/2015/saraxuss/04/17/gou/1/3.jpg");
urlList.add("http://s2.nuomi.bdimg.com/upload/deal/2014/1/V_L/623682-1391756281052.jpg");
urlList.add("http://media.chunyuyisheng.com/media/images/2013/05/15/9173ce6d26d9.jpg");
urlList.add("http://img1.imgtn.bdimg.com/it/u=1856251628,4049763171&fm=21&gp=0.jpg");
DisplayImageOptions options = new DisplayImageOptions.Builder()
.cacheInMemory(true).displayer(new RoundedBitmapDisplayer(50))
.displayer(new FadeInBitmapDisplayer(100)).cacheOnDisk(true)
.bitmapConfig(Bitmap.Config.RGB_565).build();

ImageView imageView;
for (int i = 0; i < 4; i++) {
imageView = new ImageView(MainActivity.this);
imageView.setScaleType(ScaleType.FIT_XY);
// 使用的ImageLoader网络加载图片，需先在Application和清单文件中配置在使用
ImageLoader.getInstance().displayImage(urlList.get(i), imageView,
options);
mList.add(imageView);
imageView.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
System.out.println("==========m==" + mCount % mList.size());
// 这里写点击图片的操作 mCount % mList.size()这个点击的第几个图片
}
});
}
}

private void initView() {
// TODO Auto-generated method stub
mViewPager = (ViewPager) findViewById(R.id.viewPager);
dot0 = (ImageView) findViewById(R.id.dot1);
dot1 = (ImageView) findViewById(R.id.dot2);
dot2 = (ImageView) findViewById(R.id.dot3);
dot3 = (ImageView) findViewById(R.id.dot4);
dots[0] = dot0;
dots[1] = dot1;
dots[2] = dot2;
dots[3] = dot3;
dot0.setSelected(true);
}

private void setListener() {
// TODO Auto-generated method stub
mViewPager.setOnPageChangeListener(new OnPageChangeListener() {

@Override
public void onPageSelected(int arg0) {
// TODO Auto-generated method stub
handler.sendMessage(Message.obtain(handler, RECORD, arg0, 0));
// 下面是控制点的变化
int j = arg0 % mList.size();
for (int i = 0; i < dots.length; i++) {
dots[i].setSelected(false);
}
dots[j].setSelected(true);
}

@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
switch (arg0) {
// 当滑动时让当前轮播停止
case ViewPager.SCROLL_STATE_DRAGGING:
handler.sendEmptyMessage(STOP);
break;
// 滑动停止时继续轮播
case ViewPager.SCROLL_STATE_IDLE:
handler.sendEmptyMessage(START);
break;
}
}
});

}
}

public class MyPagerAdapter extends PagerAdapter {

private List<ImageView> imageViews;

public MyPagerAdapter(List<ImageView> list) {
super();
imageViews = list;
// TODO Auto-generated constructor stub
}

@Override
public int getCount() {
// TODO Auto-generated method stub
return Integer.MAX_VALUE;
}

@Override
public boolean isViewFromObject(View arg0, Object arg1) {
// TODO Auto-generated method stub
return arg0 == arg1;
}

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

@Override
public Object instantiateItem(ViewGroup container, int position) {
// TODO Auto-generated method stub
// 因为实际只有几个页面但是我们要无限循环，所以取模计算出当前的是第几个页面
int i = position % imageViews.size();
// 预防负值
position = Math.abs(i);
ImageView imageView = imageViews.get(position);
ViewParent parent = imageView.getParent();
// remove掉View之前已经加到一个父控件中，否则报异常
if (parent != null) {
ViewGroup group = (ViewGroup) parent;
group.removeView(imageView);
}
container.addView(imageView);
return imageView;
}
}

<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" >

<android.support.v4.view.ViewPager
android:id="@+id/viewPager"
android:layout_width="wrap_content"
android:layout_height="200dp"
>
</android.support.v4.view.ViewPager>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:gravity="center_horizontal"
android:layout_alignBottom="@id/viewPager"
android:layout_marginBottom="10dp"
>
<ImageView
android:id="@+id/dot1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"

android:src="@drawable/dot_layout"/>
<ImageView
android:id="@+id/dot2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:src="@drawable/dot_layout"/>
<ImageView
android:id="@+id/dot3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:src="@drawable/dot_layout"/>
<ImageView
android:id="@+id/dot4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:src="@drawable/dot_layout"/>

</LinearLayout>
</RelativeLayout>

点击获取：源码demo