一般来说，viewpage 只支持图片的顺序滑动播放，在滑到边界时就再也滑不动了，如果要想继续滑动，只能向两边额外增加一张相片，即把第一张相片的位置放在最后一张图片的后面，给用户的感觉我继续滑就滑到了第一张，也就有了循环滑动的效果，而我们只需要在内部对他实际滑动到的序号做相应处理就好了。原理图如下
github上的开源控件也实现了循环滑动，我还没下下来看，一并附上地址，有兴趣的朋友可以研究下，
https://github.com/imbryk/LoopingViewPager
直接看代码
1. activity代码, 这里只是简单的viewpage用法，没啥特殊之处，不做过多解析。
public class AppMaskActivity extends RoboActivity implements View.OnClickListener {
public static final String HOME_MSG_CONTENT = "homemsg_content";
//首页消息中心弹框提示
@InjectView(R.id.rel_msg_popup_container)
private RelativeLayout mRelMsgPopupContainer;
@InjectView(R.id.vp_msg_img)
private ViewPager mVpMsgImg;
@InjectView(R.id.ll_dot_container)
private LinearLayout mLlDotContainer;
@InjectView(R.id.rel_vp_container)
private RelativeLayout mRelVpContainer;
@InjectView(R.id.iv_close)
private ImageView mIvClose;
private ArrayList<ImageView> pageViews;
private ImagePagerAdapter msgImgAdapter;
private Context context;
private List<MessageInfo> homeMessageList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_app_mask);
context = this;
mRelMsgPopupContainer.setOnClickListener(this);
mIvClose.setOnClickListener(this);
//将view装入数组
loadVpView();
if (homeMessageList == null || homeMessageList.size() == 0){
finish();
return;
}
msgImgAdapter = new ImagePagerAdapter(this, pageViews, mVpMsgImg, mLlDotContainer, homeMessageList);
mVpMsgImg.setPageMargin(120);
mVpMsgImg.setPageTransformer(true, new ZoomOutPageTransformer());
mVpMsgImg.setAdapter(msgImgAdapter);
if (pageViews.size() > 1){
mVpMsgImg.setCurrentItem(pageViews.size()/2);
}
}
private void loadVpView() {
homeMessageList = HomeMsgManager.getInstance().getHomeMsgs();
pageViews = new ArrayList<ImageView>();
for (int i = 0; i < homeMessageList.size(); i++) {
ImageView iv = new ImageView(this);
Drawable drawable = HomeMsgManager.getInstance().getLocalDrawable(context, homeMessageList.get(i).getPicUrl());
if (drawable == null){
continue;
}
iv.setImageDrawable(drawable);
pageViews.add(iv);
}
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.rel_msg_popup_container:
case R.id.iv_close:
finish();
break;
}
}
}
zoomoutpageTransform.java 这里是页面滑动的效果
public class ZoomOutPageTransformer implements ViewPager.PageTransformer {
private static final float MIN_SCALE = 0.85f;
private static final float MIN_ALPHA = 0.5f;
@SuppressLint("NewApi")
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
int pageHeight = view.getHeight();
Log.e("TAG", view + " , " + position + "");
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 1) //a页滑动至b页 ； a页从 0.0 -1 ；b页从1 ~ 0.0
{ // [-1,1]
// Modify the default slide transition to shrink the page as well
float scaleFactor = Math.max(MIN_SCALE, 1 - Math.abs(position));
float vertMargin = pageHeight * (1 - scaleFactor) / 2;
float horzMargin = pageWidth * (1 - scaleFactor) / 2;
if (position < 0) {
view.setTranslationX(horzMargin - vertMargin / 2);
} else {
view.setTranslationX(-horzMargin + vertMargin / 2);
}
// Scale the page down (between MIN_SCALE and 1)
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
// Fade the page relative to its size.
view.setAlpha(MIN_ALPHA + (scaleFactor - MIN_SCALE)
/ (1 - MIN_SCALE) * (1 - MIN_ALPHA));
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}
循环滑动处理则在adapter里实现
public class ImagePagerAdapter extends PagerAdapter implements ViewPager.OnPageChangeListener {
private static final String TAG = "state-viewpage";
private Context context;
private ViewPager viewPager;
ArrayList<ImageView> views;
private boolean mIsChanged = false;
private LinearLayout llDotContainer;
private int mCurrentPagePosition = FIRST_ITEM_INDEX;
private static int POINT_LENGTH = 0;
private static int FIRST_ITEM_INDEX = 1;
private static int IMAGE_POINT_LENGTH = 0;
private List<MessageInfo> mHomeMsgs;
private ImageView[] dotImages;
public ImagePagerAdapter(Context context, ArrayList<ImageView> viewpages, ViewPager viewPager,
LinearLayout llDotContainer, List<MessageInfo> homeMessages) {
this.context = context;
this.viewPager = viewPager;
this.llDotContainer = llDotContainer;
mHomeMsgs = homeMessages;
this.viewPager.addOnPageChangeListener(this);
views = viewpages;
initCycleViews();
initImageData();
if (views.size() > 1) {
refresDotsIndex(POINT_LENGTH / 2);
}
}
//这个方法就是将首尾两张图片分别加在两端
private void initCycleViews() {
//add two view
IMAGE_POINT_LENGTH = views.size();
if (views.size() >= 2) {
POINT_LENGTH = views.size();
ImageView prevFirst = new ImageView(context);
Drawable firstDrawable = views.get(0).getDrawable();
Drawable lastDrawable = views.get(views.size() - 1).getDrawable();
prevFirst.setImageDrawable(lastDrawable);
views.add(0, prevFirst);
ImageView prevFirst1 = new ImageView(context);
//prevFirst.setImageResource(R.drawable.ic_launcher);
prevFirst1.setImageDrawable(firstDrawable);
views.add(views.size(), prevFirst1);
//init small dots
initDots();
} else {
POINT_LENGTH = 0;
FIRST_ITEM_INDEX = 0;
}
}
//这个是图片的下标指示点，表示当前查看的图片是第几张，创建一个Linearlayout,然后动态添加imgview进去，selected状态来显示当前节点是否展示
private void initDots() {
if (IMAGE_POINT_LENGTH >= 2) {
dotImages = new ImageView[IMAGE_POINT_LENGTH];
for (int i = 0; i < IMAGE_POINT_LENGTH; i++) {
ImageView dot = new ImageView(context);
dot.setBackgroundResource(R.drawable.sel_dot_focused);
if (i == 0) dot.setSelected(true);
llDotContainer.addView(dot);
dotImages[i] = dot;
}
}
}
//这个函数是给初始数据，打开就是一个demo了，从网络下直接加载图片显示，url在数组里给出
private void initImageData() {
// for (int i = 0; i < arrarys.length + 2; i++) {
// ImageView imageView = views.get(i);
//// view 0 1 2 3 4 5
//// data 4 1 2 3 4 0
// if (i == 0) {
// Picasso.with(context).load(arrarys[arrarys.length - 1]).into(imageView);
// } else if (i == arrarys.length + 1) {
// Picasso.with(context).load(arrarys[0]).into(imageView);
// } else {
// Picasso.with(context).load(arrarys[i-1]).into(imageView);
// }
// }
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
ImageView imageView = (ImageView) views.get(position);
imageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//todo 页面点击事件在这里实现
}
});
container.addView(imageView);
return imageView;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
@Override
public int getCount() {
return views.size();
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(final int position) {
mIsChanged = true;
if (position > POINT_LENGTH) {
mCurrentPagePosition = FIRST_ITEM_INDEX;
} else if (position < FIRST_ITEM_INDEX) {
mCurrentPagePosition = POINT_LENGTH;
} else {
mCurrentPagePosition = position;
}
Log.i(TAG, "当前的位置是 " + mCurrentPagePosition);
}
@Override
public void onPageScrollStateChanged(int state) {
System.err.println("-------state------>" + state);
System.err.println("-------state-vitem----->" + viewPager.getCurrentItem());
switch (state) {
//在滚动完成之后
case ViewPager.SCROLL_STATE_IDLE:
if (mIsChanged) {
mIsChanged = false;
viewPager.setCurrentItem(mCurrentPagePosition, false);
refresDotsIndex(mCurrentPagePosition - 1);
Log.i(TAG, "set current " + mCurrentPagePosition);
}
break;
}
}
public void refresDotsIndex(int curr) {
for (int i = 0; i < IMAGE_POINT_LENGTH; i++) {
if (i == curr) {
dotImages[i].setSelected(true);
} else {
dotImages[i].setSelected(false);
}
}
}
}
最后再看布局文件
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/rel_msg_popup_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/mask_bg"> <RelativeLayout
android:id="@+id/rel_vp_container"
android:layout_width="250dp"
android:layout_height="300dp"
android:background="@android:color/transparent"
android:layout_centerInParent="true"> <android.support.v4.view.ViewPager
android:id="@+id/vp_msg_img"
android:layout_width="500dp"
android:layout_height="600dp"
android:layout_centerInParent="true"
android:flipInterval="30"
android:persistentDrawingCache="animation" /> <LinearLayout
android:id="@+id/ll_dot_container"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@id/vp_msg_img"
android:layout_centerInParent="true"
android:background="@android:color/transparent"
android:orientation="horizontal" />
</RelativeLayout> <ImageView
android:id="@+id/iv_close"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/rel_vp_container"
android:layout_centerInParent="true"
android:layout_marginTop="10dp"
android:src="@drawable/close" />
</RelativeLayout>
图标指示的小圆点selector文件
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:drawable="@drawable/oval" android:state_selected="true"/>
<item android:drawable="@drawable/oval_unsel" android:state_selected="false"/> </selector>
静态效果图如下，在这也就不上实际效果图了，这个界面还是透明的界面，整个图片是悬浮在上面的效果，透明界面见 http://www.cnblogs.com/lovemo1314/p/6108777.html,