MainActivity.java: package zkx.com.viewpager; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.TextView; import java.util.ArrayList; public class MainActivity extends AppCompatActivity implements ViewPager.OnPageChangeListener { private ViewPager viewPager; private ArrayList<ImageView> imageListView; private LinearLayout ll_point_contaniner; private String[] contentDesc; private TextView tv_desc; private int priviousSelectedPosition = 0; boolean isRunning = false;//isUIvisable // private ArrayList<View> pointsView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView();//初始化布局View视图 //Model数据 initData(); //Controller控制器 initAdapter(); //开启自动轮播循环 new Thread(){ @Override public void run() { isRunning = true; while(isRunning ){ try { Thread.sleep(2000); } catch (InterruptedException e) { e.printStackTrace(); } runOnUiThread(new Runnable() { @Override public void run() { System.out.println("设置当前位置: " + viewPager.getCurrentItem()); //往下跳一位 viewPager.setCurrentItem(viewPager.getCurrentItem() + 1); } }); } } }.start(); } @Override protected void onDestroy() { super.onDestroy(); isRunning=false;//界面销毁置为false } private void initView() { viewPager= (ViewPager) findViewById(R.id.viewPager); viewPager.setOnPageChangeListener(this);//设置滚动监听 //viewPager.setOffscreenPageLimit(1);//左右各保留几个对象 ll_point_contaniner= (LinearLayout) findViewById(R.id.ll_point_contaniner); tv_desc = (TextView) findViewById(R.id.tv_desc); } private void initData() { //初始化要显示的数据 //图片资源id数组 int[] imageResIds=new int[]{R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d,R.drawable.e}; //文本描述 contentDesc = new String[]{ "周杰伦", "张学友", "李克勤", "陈奕迅", "郑中基" }; //初始化要展示的5个imageView imageListView= new ArrayList<ImageView>(); // pointsView =new ArrayList<View>(); ImageView imageView; View pointView; LinearLayout.LayoutParams layoutParams; for (int i = 0; i <imageResIds.length ; i++) { imageView = new ImageView(this); imageView.setBackgroundResource(imageResIds[i]); imageListView.add(imageView); //加小白点,指示器 pointView=new View(this); pointView.setBackgroundResource(R.drawable.seletor_bg_point); layoutParams= new LinearLayout.LayoutParams(5,5); if(i!=0) layoutParams.leftMargin = 15; pointView.setEnabled(false); ll_point_contaniner.addView(pointView,layoutParams); } } private void initAdapter() { ll_point_contaniner.getChildAt(0).setEnabled(true); tv_desc.setText(contentDesc[0]); //设置适配器 viewPager.setAdapter(new MyAdpater()); //(为了实现向左无限循环)默认到中间的某个位置 // int pos=Integer.MAX_VALUE/2-(Integer.MAX_VALUE/2%imageListView.size()); viewPager.setCurrentItem(5000000);//设置到某个位置 } class MyAdpater extends PagerAdapter{ @Override public int getCount() { // return imageListView.size(); return Integer.MAX_VALUE;//伪无限循环 } //1.返回要显示的内容,创建条目 @Override public Object instantiateItem(ViewGroup container, int position) { System.out.println("instantiateItem初始化: "+position); //container:容器:ViewPager //position:当前要显示条目的位置 int newPosition = position%imageListView.size(); ImageView imageView =imageListView.get(newPosition); //a.把View对象添加到container中 container.addView(imageView); //b.把View对象返回给框架(适配器) return imageView;//必需重写,否则报异常 } /** *2.销毁条目 * @param container * @param position * @param object 要销毁的对象 */ @Override public void destroyItem(ViewGroup container, int position, Object object) { System.out.println("destroyItem销毁: "+position); container.removeView((View) object); } //3.指定复用的判断逻辑,固定写法 @Override public boolean isViewFromObject(View view, Object object) { //当滑到新的条目时,又返回来 ,view是否可以被复用 //返回判断规则 return view==object; } } @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { //滚动时调用 } @Override public void onPageSelected(int position) { //新的条目被选中时调用 System.out.println("onPageSelected: " + position); int newPosition = position%imageListView.size(); tv_desc.setText(contentDesc[newPosition]); // for (int i = 0; i < ll_point_contaniner.getChildCount(); i++) { // ll_point_contaniner.getChildAt(position).setEnabled(position==i); // } //把之前的禁用,把最新的启用,更新指示器 // (顺序不能调换,因为第一个显示的priviousSelectedPosition==newPosition==0,调换后,第一个显示的点将被禁掉) ll_point_contaniner.getChildAt(priviousSelectedPosition).setEnabled(false);//之前的禁用 ll_point_contaniner.getChildAt(newPosition).setEnabled(true);//最新的(现在的)启用 priviousSelectedPosition = newPosition;//记录之前的位置 } @Override public void onPageScrollStateChanged(int state) { //滚动状态变化时调用 } }
activity_main.xml: <?xml version="1.0" encoding="utf-8"?> <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="zkx.com.viewpager.MainActivity"> <RelativeLayout android:layout_width="match_parent" android:layout_height="160dp"> <android.support.v4.view.ViewPager android:id="@+id/viewPager" android:layout_width="match_parent" android:layout_height="match_parent"/> <LinearLayout android:layout_width="match_parent" android:layout_height="40dp" android:orientation="vertical" android:padding="5dp" android:background="#66000000" android:layout_alignParentBottom="true" android:gravity="center_horizontal"> <TextView android:id="@+id/tv_desc" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textColor="@android:color/white" android:singleLine="true" android:text="天王盖地虎,天王盖地虎,天王盖地虎"/> <LinearLayout android:id="@+id/ll_point_contaniner" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="5dp" android:orientation="horizontal"></LinearLayout> </LinearLayout> </RelativeLayout> </RelativeLayout>
以下三个xml文件建在drawable目录下
seletor_bg_point.xml: <?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_enabled="true" android:drawable="@drawable/shape_bg_point_enable"/> <item android:state_enabled="false" android:drawable="@drawable/shape_bg_point_disable"/> </selector>
shape_bg_point_disable.xml: <?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"> <corners android:radius="5dp"/> <solid android:color="@android:color/darker_gray"/> </shape>
shape_bg_point_enable.xml: <?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"> <corners android:radius="5dp"/> <solid android:color="#FFFFFF"/> </shape>
轮播广告图需要用的图片资源可以在附件中下载,也可以用自己指定的图片