🔥码云GVP开源项目 12k star Uniapp+ElementUI 功能强大 支持多语言、二开方便! 广告
图片轮播是类似知乎日报上的一个轮播效果,如下图。 ![](https://box.kancloud.cn/2016-03-01_56d5568cd577c.jpg) 好了直接进入正题,首先是出示一下效果: ![](https://box.kancloud.cn/2016-03-01_56d5568d1e7de.jpg) MainActivity: ~~~ import java.util.ArrayList; import java.util.List; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; import android.os.Bundle; import android.app.Activity; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.support.v4.view.ViewPager.OnPageChangeListener; import android.view.View; import android.view.ViewGroup; import android.widget.ImageView; import android.widget.ImageView.ScaleType; import android.widget.LinearLayout; import android.widget.TextView; public class MainActivity extends Activity { //viewpager private ViewPager view_pager; private LinearLayout ll_dotGroup; private TextView newsTitle; private int imgResIds[] = new int[]{R.drawable.a, R.drawable.b, R.drawable.c, R.drawable.d, R.drawable.b}; //存储5张图片 private String textview[]=new String[]{"12412515125","fawfafawf" ,"13f1f12f211","1251f1f12","1t1f12f121"}; //存储5个目录 private int curIndex = 0; //用来记录当前滚动的位置 PicsAdapter picsAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); setViewPager(); } private void setViewPager() { newsTitle=(TextView)findViewById(R.id.NewsTitle); view_pager = (ViewPager) findViewById(R.id.view_pager); ll_dotGroup = (LinearLayout) findViewById(R.id.dotgroup); picsAdapter = new PicsAdapter(); // 创建适配器 picsAdapter.setData(imgResIds); view_pager.setAdapter(picsAdapter); // 设置适配器 view_pager.setOnPageChangeListener(new MyPageChangeListener()); //设置页面切换监听器 initPoints(imgResIds.length); // 初始化图片小圆点 startAutoScroll(); // 开启自动播放 } // 初始化图片轮播的小圆点和目录 private void initPoints(int count) { for (int i = 0; i < count; i++) { ImageView iv = new ImageView(this); LinearLayout.LayoutParams params = new LinearLayout.LayoutParams( 20, 20); params.setMargins(0, 0, 20, 0); iv.setLayoutParams(params); iv.setImageResource(R.drawable.dot1); ll_dotGroup.addView(iv); } ((ImageView) ll_dotGroup.getChildAt(curIndex)) .setImageResource(R.drawable.dot2); newsTitle.setText(textview[curIndex]); } // 自动播放 private void startAutoScroll() { ScheduledExecutorService scheduledExecutorService = Executors .newSingleThreadScheduledExecutor(); // 每隔4秒钟切换一张图片 scheduledExecutorService.scheduleWithFixedDelay(new ViewPagerTask(), 5, 4, TimeUnit.SECONDS); } // 切换图片任务 private class ViewPagerTask implements Runnable { @Override public void run() { runOnUiThread(new Runnable() { @Override public void run() { int count = picsAdapter.getCount(); view_pager.setCurrentItem((curIndex + 1) % count); } }); } } // 定义ViewPager控件页面切换监听器 class MyPageChangeListener implements OnPageChangeListener { @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override public void onPageSelected(int position) { ImageView imageView1 = (ImageView) ll_dotGroup.getChildAt(position); ImageView imageView2 = (ImageView) ll_dotGroup.getChildAt(curIndex); if (imageView1 != null) { imageView1.setImageResource(R.drawable.dot2); } if (imageView2 != null) { imageView2.setImageResource(R.drawable.dot1); } curIndex = position; newsTitle.setText(textview[curIndex]); } boolean b = false; @Override public void onPageScrollStateChanged(int state) { //这段代码可不加,主要功能是实现切换到末尾后返回到第一张 switch (state) { case 1:// 手势滑动 b = false; break; case 2:// 界面切换中 b = true; break; case 0:// 滑动结束,即切换完毕或者加载完毕 // 当前为最后一张,此时从右向左滑,则切换到第一张 if (view_pager.getCurrentItem() == view_pager.getAdapter() .getCount() - 1 && !b) { view_pager.setCurrentItem(0); } // 当前为第一张,此时从左向右滑,则切换到最后一张 else if (view_pager.getCurrentItem() == 0 && !b) { view_pager.setCurrentItem(view_pager.getAdapter() .getCount() - 1); } break; default: break; } } } // 定义ViewPager控件适配器 class PicsAdapter extends PagerAdapter { private List<ImageView> views = new ArrayList<ImageView>(); @Override public int getCount() { if (views == null) { return 0; } return views.size(); } public void setData(int[] imgResIds) { for (int i = 0; i < imgResIds.length; i++) { ImageView iv = new ImageView(MainActivity.this); ViewGroup.LayoutParams params = new ViewGroup.LayoutParams( ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT); iv.setLayoutParams(params); iv.setScaleType(ScaleType.FIT_XY); //设置ImageView的属性 iv.setImageResource(imgResIds[i]); views.add(iv); } } public Object getItem(int position) { if (position < getCount()) return views.get(position); return null; } @Override public boolean isViewFromObject(View arg0, Object arg1) { return arg0 == arg1; } @Override public void destroyItem(View container, int position, Object object) { if (position < views.size()) ((ViewPager) container).removeView(views.get(position)); } @Override public int getItemPosition(Object object) { return views.indexOf(object); } @Override public Object instantiateItem(View container, int position) { if (position < views.size()) { final ImageView imageView = views.get(position); ((ViewPager) container).addView(imageView); return views.get(position); } return null; } } } ~~~ activity_main: ~~~ <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" > <RelativeLayout android:layout_width="match_parent" android:layout_height="150dp" android:layout_marginBottom="5dp" android:orientation="vertical" > <android.support.v4.view.ViewPager android:id="@+id/view_pager" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center" > </android.support.v4.view.ViewPager> <RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:background="@drawable/focus_bg" > <TextView android:id="@+id/NewsTitle" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="我校交换生演讲比赛夺冠 美国华盛本大学万里发来贺电" android:paddingTop="10dp" android:paddingBottom="8dp" android:paddingLeft="10dp" android:paddingRight="100dp" android:textSize="15sp" android:textColor="#fff"/> <LinearLayout android:id="@+id/dotgroup" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentRight="true" android:paddingTop="23dp" android:paddingRight="10dp" android:gravity="center" android:layout_marginBottom="15dp" android:orientation="horizontal" > </LinearLayout> </RelativeLayout> </RelativeLayout> </RelativeLayout> ~~~ 最后附上源码:[http://download.csdn.net/detail/double2hao/9155675](http://download.csdn.net/detail/double2hao/9155675) 本人博客,android均为新手,闻过则喜,望各位前辈不吝批评指点。