顶部轮播图(自动循环滚动)

骑猪看日落 2022-08-01 00:17 179阅读 0赞

1.MainActivity:

public class MainActivity extends Activity {
    
    	private ViewPager viewPager;
    	private TextView tv_title;
    	private LinearLayout dot_layout;
    	private ArrayList<Ad> list = new ArrayList<Ad>();
    	// 使用handler实现自动循环滚动图片
    	private Handler handler = new Handler() {
    		public void handleMessage(android.os.Message msg) {
    			viewPager.setCurrentItem(viewPager.getCurrentItem() + 1);
    			if (isRunning) {
    				handler.sendEmptyMessageDelayed(0, 5000);
    			}
    		};
    	};
    	private boolean isRunning = false;
    
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		initView();
    		initListener();
    		initData();
    
    	}
    
    	private void initView() {
    		setContentView(R.layout.activity_main);
    		viewPager = (ViewPager) findViewById(R.id.viewPager);
    		tv_title = (TextView) findViewById(R.id.tv_title);
    		dot_layout = (LinearLayout) findViewById(R.id.dot_layout);
    		isRunning = true;
    		handler.sendEmptyMessageDelayed(0, 2000);
    	}
    
    	private void initListener() {
    
    		viewPager.setOnPageChangeListener(new OnPageChangeListener() {
    
    			@Override
    			public void onPageSelected(int arg0) {
    				updateTitleAndDots();
    			}
    
    			@Override
    			public void onPageScrolled(int arg0, float arg1, int arg2) {
    
    			}
    
    			@Override
    			public void onPageScrollStateChanged(int arg0) {
    
    			}
    		});
    	}
    
    	private void initData() {
    		list.add(new Ad(R.drawable.a, "巩俐不低俗，我们就不低俗"));
    		list.add(new Ad(R.drawable.b, "朴树又回来了，再唱经典老歌引万人同唱"));
    		list.add(new Ad(R.drawable.c, "揭秘北京电影如何升级"));
    		list.add(new Ad(R.drawable.d, "乐视网TV版，大放送"));
    		list.add(new Ad(R.drawable.e, "热血屌丝的反杀"));
    
    		initDots();
    		viewPager.setAdapter(new AdPagerAdapter());
    		updateTitleAndDots();
    	}
    
    	/**
    	 * 初始化点
    	 */
    	private void initDots() {
    		for (int i = 0; i < list.size(); i++) {
    			View view = new View(this);
    			LayoutParams params = new LayoutParams(15, 15);// 设置点的大小
    			if (i != 0) {
    				params.leftMargin = 10;
    			}
    			view.setLayoutParams(params);
    			view.setBackgroundResource(R.drawable.selector_dot);
    			dot_layout.addView(view);
    		}
    	}
    
    	/**
    	 * 更新文本
    	 */
    	private void updateTitleAndDots() {
    		int currentPager = viewPager.getCurrentItem() % list.size();
    		tv_title.setText(list.get(currentPager).getTitle());
    
    		for (int i = 0; i < dot_layout.getChildCount(); i++) {
    			dot_layout.getChildAt(i).setEnabled(i == currentPager);
    		}
    	}
    
    	private class AdPagerAdapter extends PagerAdapter {
    
    		/**
    		 * 返回多少Pager
    		 */
    		@Override
    		public int getCount() {
    			return 100;
    		}
    
    		/**
    		 * true:表示不去创建，使用缓存 false:表示去重新创建
    		 */
    		@Override
    		public boolean isViewFromObject(View view, Object object) {
    			return view == object;
    		}
    
    		/**
    		 * 类似于BaseAdapter的getView方法, 用来将数据设置给view
    		 */
    		@Override
    		public Object instantiateItem(ViewGroup container, int position) {
    			View view = View.inflate(MainActivity.this, R.layout.adapter_ad, null);
    			ImageView imaView = (ImageView) view.findViewById(R.id.image);
    
    			Ad ad = list.get(position % list.size());// 对position取余，实现循环滑动
    			imaView.setImageResource(ad.getResId());
    			container.addView(view);// 将view加入到ViewPager
    			return view;
    		}
    
    		/**
    		 * 销毁pager position:当前要销毁的是第几个pager object:当前要销毁的pager
    		 */
    		@Override
    		public void destroyItem(ViewGroup container, int position, Object object) {
    			container.removeView((View) object);
    		}
    
    	}
    
    	@Override
    	protected void onDestroy() {
    		super.onDestroy();
    		isRunning = false;// 停止自动轮播效果
    	}
    }

2.数据bean，Ad.class

public class Ad {
    
    	private int resId;
    	private String title;
    
    	public Ad(int resId, String title) {
    		super();
    		this.resId = resId;
    		this.title = title;
    	}
    
    	public int getResId() {
    		return resId;
    	}
    
    	public void setResId(int resId) {
    		this.resId = resId;
    	}
    
    	public String getTitle() {
    		return title;
    	}
    
    	public void setTitle(String title) {
    		this.title = title;
    	}
    
    }

3.activity\_main.xml

4.adapter\_ad.xml:

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical" >
    
        <ImageView
            android:id="@+id/image"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scaleType="fitXY"
            android:src="@drawable/a" />
    
    </LinearLayout>

Demo地址：http://download.csdn.net/detail/qq\_26323183/8807327