Android上的缝循环广告位实现方法似乎有很多种方法，还有的大神用RecyclerView实现了。但是，我试了一下用ViewPager，好像这个更简便一点。
先看一下效果图：
ViewPagerAD.gif
demo中用到了：
- Gson 一个谷歌的Json解析库，速度快，很好用。
- Glide 用于加载图片的第三方库，如丝般顺畅。
- Volley 网络请求的第三方库，比较早就有了，现在仍很多人用。
如果对以上这三个库不了解的话，建议先去看看。
初始化那些什么的就不说了，我们直接说重点的。
布局
很简单，ViewPager+LinearLayout。底下的LinearLayout是用来显示圆点的。
实现过程
既然用到ViewPager，肯定需要一个适配器PagerAdapter：
class MyAdapter extends PagerAdapter {
@Override
public int getCount() {
return Integer.MAX_VALUE; //最大值，可以认为无限大，反正你划不到尽头就行了
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
@Override
public Object instantiateItem(ViewGroup container, final int position) {
//在0~imageViewList.size()之间循环
int index = position % imageViewList.size();
imageViewList.get(index).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//处理图片点击事件....
Log.e("点击图片：",position % imageViewList.size()+"");
}
});
if (imageViewList.size() > 0) {
View view = imageViewList.get(index);
if (container.equals(view.getParent())) {
container.removeView(view);
}
container.addView(view);
return view;
}
return null;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
int index = position % imageViewList.size();
container.removeView(imageViewList.get(index));
}
}
然后用Volley请求网络，拿到数据：
RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
StringRequest request = new StringRequest(URL, new Response.Listener() {
@Override
public void onResponse(String s) {
//拿到网络请求的数据
doSomething(s);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError volleyError) {
Log.e(TGA, "", volleyError);
}
});
requestQueue.add(request);
用Gson解析，得到图片的Url的List，即imgs。同时new一个ImageView，用Glide加载后添加到image的List即imageViewList，ImageView dot为小圆点。设置适配器，启动线程：
private void doSomething(String s) {
DataInfo info = gson.fromJson(s, DataInfo.class);
DataInfo.DataEntity entity = info.getData();
imgs = entity.getImgs();
for (int i = 0; i < imgs.size(); i++) {
ImageView imageView = new ImageView(this);
imageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
Glide.with(this)
.load(imgs.get(i).getPic_url_yasha())
.diskCacheStrategy(DiskCacheStrategy.ALL)
.into(imageView);
imageViewList.add(imageView);
ImageView dot = new ImageView(this);
dot.setImageResource(R.drawable.point_normal);
dot.setPadding(10, 5, 10, 5);
linearLayout.addView(dot);
}
MyAdapter adapter = new MyAdapter();
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(currentIndex);
viewPager.addOnPageChangeListener(this);
handler.post(r);
}
用于循环播放的线程：
private Handler handler = new Handler();
Runnable r = new Runnable() {
@Override
public void run() {
if (isCyclical) {
if (System.currentTimeMillis() - lastTime > 2000) {
currentIndex++;
viewPager.setCurrentItem(currentIndex);
lastTime = System.currentTimeMillis();
}
//递归循环，图片切换速度3秒一张
handler.postDelayed(r, 3000);
}
}
};
伴随图片切换而切换的底部小圆点：
private void setCurrentSelector(int index) {
for (int i = 0; i < linearLayout.getChildCount(); i++) {
ImageView child = (ImageView) linearLayout.getChildAt(i);
if (i == index) {
child.setImageResource(R.drawable.point_selected);
} else {
child.setImageResource(R.drawable.point_normal);
}
}
}
最后在onDestroy()方法里面把循环线程停掉，不然你退出程序它还在运行：
@Override
protected void onDestroy() {
super.onDestroy();
isCyclical = false; //Activity退出后，图片循环线程停止
}
主要实现过程就酱紫~
附上全部代码:
package com.sonnyzoom.viewpagerad;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.bumptech.glide.Glide;
import com.bumptech.glide.load.engine.DiskCacheStrategy;
import com.google.gson.Gson;
import com.sonnyzoom.viewpagerad.bean.DataInfo;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity implements ViewPager.OnPageChangeListener {
public static final String URL = "http://spark.api.xiami.com/sdk?v=sdk&method=mobile.sdk-image&device_id=de717e77-6330-3c13-b601-e3c6228d4f16&api_key=bbf59448b1d2a0254d033bfe3b4d8a30&call_id=1443063251736&api_sig=5c29b6c2ffed24d7f5b481d7deb0511e";
public static final String TGA = "MainActivity";
private ViewPager viewPager;
private LinearLayout linearLayout;
private List imgs;
private List imageViewList;
private int currentIndex=300; //初始值可以设置大一点，防止左划到尽头。
private long lastTime;
private Gson gson;
private boolean isCyclical = true;
private Handler handler = new Handler();
Runnable r = new Runnable() {
@Override
public void run() {
if (isCyclical) {
if (System.currentTimeMillis() - lastTime > 2000) {
currentIndex++;
viewPager.setCurrentItem(currentIndex);
lastTime = System.currentTimeMillis();
}
//递归循环，图片切换速度3秒一张
handler.postDelayed(r, 3000);
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
viewPager = (ViewPager) findViewById(R.id.viewPager);
linearLayout = (LinearLayout) findViewById(R.id.linearLayout);
imgs = new ArrayList<>();
imageViewList = new ArrayList<>();
gson = new Gson();
RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
StringRequest request = new StringRequest(URL, new Response.Listener() {
@Override
public void onResponse(String s) {
//拿到网络请求的数据
doSomething(s);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError volleyError) {
Log.e(TGA, "", volleyError);
}
});
requestQueue.add(request);
}
private void doSomething(String s) {
DataInfo info = gson.fromJson(s, DataInfo.class);
DataInfo.DataEntity entity = info.getData();
imgs = entity.getImgs();
for (int i = 0; i < imgs.size(); i++) {
ImageView imageView = new ImageView(this);
imageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
Glide.with(this)
.load(imgs.get(i).getPic_url_yasha())
.diskCacheStrategy(DiskCacheStrategy.ALL)
.into(imageView);
imageViewList.add(imageView);
ImageView dot = new ImageView(this);
dot.setImageResource(R.drawable.point_normal);
dot.setPadding(10, 5, 10, 5);
linearLayout.addView(dot);
}
MyAdapter adapter = new MyAdapter();
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(currentIndex);
viewPager.addOnPageChangeListener(this);
handler.post(r);
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(final int position) {
Log.e("位置：", position + "");
currentIndex = position;
int index = position % imageViewList.size();
setCurrentSelector(index);
lastTime = System.currentTimeMillis();
}
@Override
public void onPageScrollStateChanged(int state) {
}
private void setCurrentSelector(int index) {
for (int i = 0; i < linearLayout.getChildCount(); i++) {
ImageView child = (ImageView) linearLayout.getChildAt(i);
if (i == index) {
child.setImageResource(R.drawable.point_selected);
} else {
child.setImageResource(R.drawable.point_normal);
}
}
}
class MyAdapter extends PagerAdapter {
@Override
public int getCount() {
return Integer.MAX_VALUE; //最大值，可以认为无限大，反正你划不到尽头就行了
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
@Override
public Object instantiateItem(ViewGroup container, final int position) {
//在0~imageViewList.size()之间循环
int index = position % imageViewList.size();
imageViewList.get(index).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//处理图片点击事件....
Log.e("点击图片：",position % imageViewList.size()+"");
}
});
if (imageViewList.size() > 0) {
View view = imageViewList.get(index);
if (container.equals(view.getParent())) {
container.removeView(view);
}
container.addView(view);
return view;
}
return null;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
int index = position % imageViewList.size();
container.removeView(imageViewList.get(index));
}
}
@Override
protected void onDestroy() {
super.onDestroy();
isCyclical = false; //Activity退出后，图片循环线程停止
}
}
源码已上传：Github
有什么错误或者建议可以在评论下面留言。