Android(安卓)Banner 简单实现

参考 http://www.jianshu.com/p/f8bf9e8b0a39

ViewPageAdapter

public class ViewPagerAdapter extends PagerAdapter {    private List data;    public ViewPagerAdapter(List data) {        this.data = data;    }    @Override    public int getCount() {        return data.size();    }    @Override    public boolean isViewFromObject(View view, Object object) {        return view == object;    }    @Override    public Object instantiateItem(ViewGroup container, int position) {        ImageView imageView = new ImageView(container.getContext());        imageView.setScaleType(ImageView.ScaleType.CENTER);        imageView.setBackgroundResource(data.get(position));        container.addView(imageView);        return imageView;//        return super.instantiateItem(container, position);    }    @Override    public void destroyItem(ViewGroup container, int position, Object object) {        container.removeView((View) object);//        super.destroyItem(container, position, object);    }}

布局

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    tools:context="com.example.alex.viewpagerdemo.MainActivity">    <FrameLayout        android:layout_width="match_parent"        android:layout_height="wrap_content">        <android.support.v4.view.ViewPager            android:id="@+id/viewpager"            android:layout_width="match_parent"            android:layout_height="200dp">android.support.v4.view.ViewPager>        <RelativeLayout            android:layout_width="match_parent"            android:layout_height="40dp"            android:layout_gravity="bottom"            android:background="#9977">            <TextView                android:id="@+id/banner_title"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:text="怎么了"                android:gravity="center_vertical"                android:textColor="@android:color/white"                android:paddingLeft="20dp"/>            <TextView                android:id="@+id/banner_indicator"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:text="1/4"                android:gravity="center_vertical"                android:textColor="@android:color/white"                android:layout_alignParentRight="true"                android:layout_marginRight="20dp"/>        RelativeLayout>    FrameLayout>    <Button        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="SortLayout"        android:textAllCaps="false"        android:onClick="sort"/>LinearLayout>

MainActivity

public class MainActivity extends AppCompatActivity {    ViewPager viewPager;    ViewPagerAdapter adapter;    List data;    List titleData;    int currentPage = 0;    boolean viewPagerScrollStatus = false; //标志位,当在手动翻页时,自动翻页暂停    TextView title, indicator;    Handler handler = new Handler() {        @Override        public void handleMessage(Message msg) {            if (!viewPagerScrollStatus) {                viewPager.setCurrentItem(++currentPage);            }            handler.sendEmptyMessageDelayed(1, 1000);        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        viewPager = (ViewPager) findViewById(R.id.viewpager);        title = (TextView) findViewById(R.id.banner_title);        indicator = (TextView) findViewById(R.id.banner_indicator);        data = new ArrayList<>(); titleData = new ArrayList<>();        data.add(R.mipmap.t);     titleData.add("4.哦");        data.add(R.mipmap.a);     titleData.add("1.怎么了");        data.add(R.mipmap.b);     titleData.add("2.没事");        data.add(R.mipmap.c);     titleData.add("3.那好吧");        data.add(R.mipmap.t);     titleData.add("4.哦");        data.add(R.mipmap.a);     titleData.add("1.怎么了");        adapter = new ViewPagerAdapter(data);        viewPager.setAdapter(adapter);        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {            @Override            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {            }            @Override            public void onPageSelected(int position) {                //头尾衔接,无限循环                if (position == data.size() - 1) {                    currentPage = 1;                } else if (position == 0) {                    currentPage = data.size() - 2;                } else {                    currentPage = position;                }            }            @Override            public void onPageScrollStateChanged(int state) {                if (state == ViewPager.SCROLL_STATE_IDLE) {                    viewPagerScrollStatus = false;                    viewPager.setCurrentItem(currentPage, false);                    title.setText(titleData.get(currentPage));                    indicator.setText(currentPage + "/" + (titleData.size() - 2));                } else {                    viewPagerScrollStatus = true;                }            }        });        handler.sendEmptyMessageDelayed(1, 1000);        viewPager.setPageTransformer(true, new ViewPager.PageTransformer() {            @Override            public void transformPage(View page, float position) {                int width = page.getWidth();                //我们给不同状态的页面设置不同的效果                //通过position的值来分辨页面所处于的状态                if (position < -1) {//滑出的页面                    page.setScrollX((int) (width * 0.75 * -1));                } else if (position <= 1) {//[-1,1]                    if (position < 0) {//[-1,0]                        page.setScrollX((int) (width * 0.75 * position));                    } else {//[0,1]                        page.setScrollX((int) (width * 0.75 * position));                    }                } else {//即将滑入的页面                    page.setScrollX((int) (width * 0.75));                }            }        });    }    public void sort(View v) {        startActivity(new Intent(this, SortLayoutActivity.class));    }}

效果

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