viewpager实现轮播图效果

public class BannerViewPager extends ViewPager {

private TextView textView;
private LinearLayout linearLayout;
private final int SCROLL_BORDER = 2, TIMER_UPDATE = 3;
private MiniBannerViewPagerAdapter adapter;
private Timer timer;

public interface MiniBannerViewPagerAdapter {
int bannerImageCount();//图片的总数

String bannerImageUrlAtIndex(int index);//通过index获取对象图片里的url

String bannerTextAtIndex(int index); //通过index获取对象的title

void bannerDidSelectAtIndex(int index); //点击把当前的对象返回进行相应的操作
}

private Handler handler = new Handler() {
public void handleMessage(Message msg) {
switch (msg.what) {
case TIMER_UPDATE: {
int count = adapter.bannerImageCount();
int index = getCurrentItem();
index = (index + 1) % (count + 2);
setCurrentItem(index);
break;
}
case SCROLL_BORDER: {
int count = adapter.bannerImageCount();
int current = getCurrentItem();
if (current == 0) {
setCurrentItem(count, false);
} else if (current == count + 1) {
setCurrentItem(1, false);
}
break;
}
}
}
};

public MiniBannerViewPager(Context context) {
super(context);
}

public MiniBannerViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}

public void setRootView(View view) {
this.textView = (TextView) view.findViewById(R.id.banner_text);
this.linearLayout = (LinearLayout) view.findViewById(R.id.banner_layout);
}

private void stopTimer() {
if (timer != null) {
timer.cancel();
timer = null;
}
}

public void setPagerAdapter(MiniBannerViewPagerAdapter adapter) {
this.stopTimer();
this.adapter = adapter;
if (this.adapter != null) {
ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter();
super.setAdapter(viewPagerAdapter);
super.setOnPageChangeListener(viewPagerAdapter);
final int count = adapter.bannerImageCount();
if (count > 1) {
// 设置展示的红点
linearLayout.setVisibility(VISIBLE);
linearLayout.removeAllViews();
for (int i = 0; i < count; i++) {
ImageView imageView = new ImageView(getContext());
imageView.setBackgroundResource(R.drawable.school_news_item_main_point_normal);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
layoutParams.leftMargin = 5;
linearLayout.addView(imageView, layoutParams);
}

this.setCurrentItem(1);
timer = new Timer();
timer.schedule(new TimerTask() {
@Override
public void run() {
handler.sendEmptyMessage(TIMER_UPDATE);
}
}, 5000, 5000);
} else {
linearLayout.setVisibility(GONE);
}
}
}

public class ViewPagerAdapter extends PagerAdapter implements OnPageChangeListener {

public String urlAtIndex(int index) {
return adapter.bannerImageUrlAtIndex(index);
}

public void onPageSelected(int var1) {
int count = adapter.bannerImageCount();
if (count > 1) {
handler.sendEmptyMessageDelayed(SCROLL_BORDER, 500);
}
int index = indexForPosition(var1);
for (int i = 0; i < linearLayout.getChildCount(); i++) {
ImageView imageView = (ImageView) linearLayout.getChildAt(i);
if (i == index) {
imageView.setBackgroundResource(R.drawable.school_news_item_main_point_pressed);
} else {
imageView.setBackgroundResource(R.drawable.school_news_item_main_point_normal);
}
}
String title = adapter.bannerTextAtIndex(index);
textView.setText(title);
}

public void onPageScrolled(int var1, float var2, int var3) {

}

public void onPageScrollStateChanged(int var1) {

}

public int getCount() {
int count = 0;
if (adapter != null) {
count = adapter.bannerImageCount();
if (count > 1) {
return count + 2;
}
}
return count;
}

public Object instantiateItem(ViewGroup container, int position) {
final int index = indexForPosition(position);
int count = adapter.bannerImageCount();
if (count == 1) {
String title = adapter.bannerTextAtIndex(index);
textView.setText(title);
}
ImageView imageView = new ImageView(container.getContext());
imageView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT));
imageView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
adapter.bannerDidSelectAtIndex(index);
}
});
Object parent = imageView.getParent();
if (parent != null && parent instanceof ViewGroup) {
((ViewGroup) parent).removeView(imageView);
}
container.addView(imageView);
imageView.setBackgroundResource(R.mipmap.ic_launcher);
return imageView;
}

private int indexForPosition(int position) {
int index = position;
if (adapter.bannerImageCount() > 1) {
if (position == 0) {
index = adapter.bannerImageCount() - 1;
} else if (position == adapter.bannerImageCount() + 1) {
index = 0;
} else {
index = position - 1;
}
}
return index;
}

public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}

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

MainActivity extends Activity implements  MiniBannerViewPager.MiniBannerViewPagerAdapter{

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initData();
mBannerViewPager = (MiniBannerViewPager) findViewById(R.id.banner_viewpager);
mBannerLayout = (RelativeLayout) findViewById(R.id.banner_relayout_layout);
mBannerViewPager.setRootView(mBannerLayout);
mBannerViewPager.setPagerAdapter(this);
}

private void initData() {
mImages = new ArrayList<Integer>();
mTitles = new ArrayList<String>();
for (int i = 0; i < 5; i++) {
mImages.add(R.drawable.icon_send);
mTitles.add("第" + i + 1 + "展示图片");
}
}

@Override
public int bannerImageCount() {
return mImages.size();
}

@Override
public String bannerImageUrlAtIndex(int index) {
return mImages.get(index).toString();
}

@Override
public String bannerTextAtIndex(int index) {
return mTitles.get(index);
}

@Override
public void bannerDidSelectAtIndex(int index) {
Toast.makeText(this, mTitles.get(index), Toast.LENGTH_LONG).show();
}

<RelativeLayout
android:id="@+id/view_feed_banner_inner"
android:layout_width="match_parent"
android:layout_height="150dp">

<com.example.BannerViewPager
android:id="@+id/banner_viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>

<RelativeLayout
android:id="@+id/banner_relayout_layout"
android:layout_width="match_parent"
android:layout_height="30dp"
android:layout_alignParentBottom="true"
android:background="#33000000"
android:paddingLeft="10dp"
android:paddingRight="10dp">

<TextView
android:id="@+id/banner_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:layout_marginRight="30dp"
android:layout_toRightOf="@+id/banner_layout"
android:singleLine="true"
android:textColor="#ffffff"
android:textSize="14sp"/>

<LinearLayout
android:id="@+id/banner_layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:orientation="horizontal"/>
</RelativeLayout>

</RelativeLayout>