viewpager实现轮播图效果

来源：互联网发布：windows 7默认壁纸编辑：程序博客网时间：2024/06/13 07:51

比较简单实用的banner效果

public class BannerViewPager extends ViewPager {private TextView textView;private LinearLayout linearLayout;private final int SCROLL_BORDER = 2, TIMER_UPDATE = 3;private MiniBannerViewPagerAdapter adapter;private Timer timer;public interface MiniBannerViewPagerAdapter {    int bannerImageCount();//图片的总数    String bannerImageUrlAtIndex(int index);//通过index获取对象图片里的url    String bannerTextAtIndex(int index); //通过index获取对象的title    void bannerDidSelectAtIndex(int index); //点击把当前的对象返回进行相应的操作}private Handler handler = new Handler() {    public void handleMessage(Message msg) {        switch (msg.what) {            case TIMER_UPDATE: {                int count = adapter.bannerImageCount();                int index = getCurrentItem();                index = (index + 1) % (count + 2);                setCurrentItem(index);                break;            }            case SCROLL_BORDER: {                int count = adapter.bannerImageCount();                int current = getCurrentItem();                if (current == 0) {                    setCurrentItem(count, false);                } else if (current == count + 1) {                    setCurrentItem(1, false);                }                break;            }        }    }};public MiniBannerViewPager(Context context) {    super(context);}public MiniBannerViewPager(Context context, AttributeSet attrs) {    super(context, attrs);}public void setRootView(View view) {    this.textView = (TextView) view.findViewById(R.id.banner_text);    this.linearLayout = (LinearLayout) view.findViewById(R.id.banner_layout);}private void stopTimer() {    if (timer != null) {        timer.cancel();        timer = null;    }}public void setPagerAdapter(MiniBannerViewPagerAdapter adapter) {    this.stopTimer();    this.adapter = adapter;    if (this.adapter != null) {        ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter();        super.setAdapter(viewPagerAdapter);        super.setOnPageChangeListener(viewPagerAdapter);        final int count = adapter.bannerImageCount();        if (count > 1) {            // 设置展示的红点            linearLayout.setVisibility(VISIBLE);            linearLayout.removeAllViews();            for (int i = 0; i < count; i++) {                ImageView imageView = new ImageView(getContext());                imageView.setBackgroundResource(R.drawable.school_news_item_main_point_normal);                LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,                        LayoutParams.WRAP_CONTENT);                layoutParams.leftMargin = 5;                linearLayout.addView(imageView, layoutParams);            }            this.setCurrentItem(1);            timer = new Timer();            timer.schedule(new TimerTask() {                @Override                public void run() {                    handler.sendEmptyMessage(TIMER_UPDATE);                }            }, 5000, 5000);        } else {            linearLayout.setVisibility(GONE);        }    }}public class ViewPagerAdapter extends PagerAdapter implements OnPageChangeListener {    public String urlAtIndex(int index) {        return adapter.bannerImageUrlAtIndex(index);    }    public void onPageSelected(int var1) {        int count = adapter.bannerImageCount();        if (count > 1) {            handler.sendEmptyMessageDelayed(SCROLL_BORDER, 500);        }        int index = indexForPosition(var1);        for (int i = 0; i < linearLayout.getChildCount(); i++) {            ImageView imageView = (ImageView) linearLayout.getChildAt(i);            if (i == index) {                imageView.setBackgroundResource(R.drawable.school_news_item_main_point_pressed);            } else {                imageView.setBackgroundResource(R.drawable.school_news_item_main_point_normal);            }        }        String title = adapter.bannerTextAtIndex(index);        textView.setText(title);    }    public void onPageScrolled(int var1, float var2, int var3) {    }    public void onPageScrollStateChanged(int var1) {    }    public int getCount() {        int count = 0;        if (adapter != null) {            count = adapter.bannerImageCount();            if (count > 1) {                return count + 2;            }        }        return count;    }    public Object instantiateItem(ViewGroup container, int position) {        final int index = indexForPosition(position);        int count = adapter.bannerImageCount();        if (count == 1) {            String title = adapter.bannerTextAtIndex(index);            textView.setText(title);        }        ImageView imageView = new ImageView(container.getContext());        imageView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,                ViewGroup.LayoutParams.MATCH_PARENT));        imageView.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                adapter.bannerDidSelectAtIndex(index);            }        });        Object parent = imageView.getParent();        if (parent != null && parent instanceof ViewGroup) {            ((ViewGroup) parent).removeView(imageView);        }        container.addView(imageView);        imageView.setBackgroundResource(R.mipmap.ic_launcher);        return imageView;    }    private int indexForPosition(int position) {        int index = position;        if (adapter.bannerImageCount() > 1) {            if (position == 0) {                index = adapter.bannerImageCount() - 1;            } else if (position == adapter.bannerImageCount() + 1) {                index = 0;            } else {                index = position - 1;            }        }        return index;    }    public void destroyItem(ViewGroup container, int position, Object object) {        container.removeView((View) object);    }    public boolean isViewFromObject(View arg0, Object arg1) {        return arg0 == (arg1);    }}

}

MainActivity code

 MainActivity extends Activity implements  MiniBannerViewPager.MiniBannerViewPagerAdapter{     @Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    initData();    mBannerViewPager = (MiniBannerViewPager) findViewById(R.id.banner_viewpager);    mBannerLayout = (RelativeLayout) findViewById(R.id.banner_relayout_layout);    mBannerViewPager.setRootView(mBannerLayout);    mBannerViewPager.setPagerAdapter(this);    }   private void initData() {    mImages = new ArrayList<Integer>();    mTitles = new ArrayList<String>();    for (int i = 0; i < 5; i++) {        mImages.add(R.drawable.icon_send);        mTitles.add("第" + i + 1 + "展示图片");    }}   @Override      public int bannerImageCount() {          return mImages.size();       }@Overridepublic String bannerImageUrlAtIndex(int index) {    return mImages.get(index).toString();}@Overridepublic String bannerTextAtIndex(int index) {    return mTitles.get(index);}@Overridepublic void bannerDidSelectAtIndex(int index) {    Toast.makeText(this, mTitles.get(index), Toast.LENGTH_LONG).show();}

activity_main.xml布局

 <RelativeLayout    android:id="@+id/view_feed_banner_inner"    android:layout_width="match_parent"    android:layout_height="150dp">    <com.example.BannerViewPager        android:id="@+id/banner_viewpager"        android:layout_width="match_parent"        android:layout_height="match_parent"        />    <RelativeLayout        android:id="@+id/banner_relayout_layout"        android:layout_width="match_parent"        android:layout_height="30dp"        android:layout_alignParentBottom="true"        android:background="#33000000"        android:paddingLeft="10dp"        android:paddingRight="10dp">        <TextView            android:id="@+id/banner_text"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_alignParentLeft="true"            android:layout_centerVertical="true"            android:layout_marginRight="30dp"            android:layout_toRightOf="@+id/banner_layout"            android:singleLine="true"            android:textColor="#ffffff"            android:textSize="14sp"/>        <LinearLayout            android:id="@+id/banner_layout"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_alignParentRight="true"            android:layout_centerVertical="true"            android:orientation="horizontal"/>    </RelativeLayout></RelativeLayout>

}

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