Android-简单的轮播图控件BannerView
由于轮播图控件比较常用，就自己封装了一个简单的轮播图控件，废话不多说，直接上代码，使用的时候直接把下面这个类加入到工程就可以了
/** * Created by skyfly on 2017/9/13. * 通用的BannerView类 */ public class BannerView extends LinearLayout implements ViewPager.OnPageChangeListener { private ViewPager mViewPager; private BannerAdapter mAdapter; private BannerViewListener mListener; private int mSelectedPageIndex = 0; private LinearLayout mIndicatorView; private BannerHandler mHandler; private boolean mIsScroll = false; private static int MSG_LOOP = 0x0001, LOOP_INTERVAL = 3000; private static class BannerHandler extends Handler { private WeakReferenceweakReference = null; public BannerHandler(BannerView bannerView) { super(Looper.getMainLooper()); this.weakReference = new WeakReference (bannerView); } @Override public void handleMessage(Message msg) { super.handleMessage(msg); if (this.weakReference == null) { return; } BannerView bannerView = this.weakReference.get(); if (bannerView == null || bannerView.mViewPager == null || bannerView.mViewPager.getAdapter() == null || bannerView.mViewPager.getAdapter().getCount() <= 1) { return; } if (!bannerView.mIsScroll) { bannerView.mViewPager.setCurrentItem(bannerView.mSelectedPageIndex+1, true); } } } public interface BannerViewListener { void onShowImage(ImageView view, String imgUrl); void onItemClick(int position, String targetUrl, Object userData); View onCreateIndicatorView(); } public BannerView(Context context) { this(context, null); } @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override public void onPageSelected(int position) { selectIndicatorView(mAdapter.getDataPosition(mSelectedPageIndex), false); mSelectedPageIndex = position; selectIndicatorView(mAdapter.getDataPosition(mSelectedPageIndex), true); } @Override public void onPageScrollStateChanged(int state) { if (state == 1) { mIsScroll = true; } else if(state == 2) { mIsScroll = false; mHandler.removeCallbacksAndMessages(null); mHandler.sendEmptyMessageDelayed(MSG_LOOP, LOOP_INTERVAL); } } public BannerView(Context context, @Nullable AttributeSet attrs) { this(context, attrs, 0); } public BannerView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); initViews(context); } private void initViews(Context context) { // 动态创建对象 RelativeLayout rl_banner = new RelativeLayout(context); rl_banner.setLayoutParams(new ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT)); this.addView(rl_banner, MATCH_PARENT, MATCH_PARENT); mViewPager = new ViewPager(context); rl_banner.addView(mViewPager, MATCH_PARENT, MATCH_PARENT); mIndicatorView = new LinearLayout(context); mIndicatorView.setOrientation(HORIZONTAL); mIndicatorView.setGravity(CENTER); RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(MATCH_PARENT, WRAP_CONTENT); lp.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM); lp.bottomMargin = (int) dip2px(context, 6); mIndicatorView.setLayoutParams(lp); rl_banner.addView(mIndicatorView); mViewPager.setAdapter(mAdapter = new BannerAdapter(this)); mViewPager.addOnPageChangeListener(this); mHandler = new BannerHandler(this); // 启动循环 mHandler.sendEmptyMessageDelayed(MSG_LOOP, LOOP_INTERVAL); } public void setBannerViewListener(BannerViewListener l) { mListener = l; } // 设置数据 public void setBannerDatas(ArrayList data) { mAdapter.setBannerDatas(data); // 移除旧的 mIndicatorView.removeAllViews(); // 添加新的 if (data.size() > 1) { for (int i = 0; i < data.size(); i++) { if (mListener != null) { mIndicatorView.addView(mListener.onCreateIndicatorView()); } } } if(data.size() > 1) { // 选中新的 selectIndicatorView(mAdapter.getDataPosition(mSelectedPageIndex), true); } } private void selectIndicatorView(int index, boolean bSelected) { View v = mIndicatorView.getChildAt(index); if (v != null) { v.setSelected(bSelected); } } private void onItemClick() { if (mListener != null) { BannerInfo info = mAdapter.getItem(mSelectedPageIndex); if(info != null) { mListener.onItemClick(mAdapter.getDataPosition(mSelectedPageIndex), info.mTargetUrl, info.mUserData); } } } private void onShowImage(ImageView v, String url) { if (mListener != null) { mListener.onShowImage(v, url); } } private float dip2px(Context context, float dpValue) { final float scale = context.getResources().getDisplayMetrics().density; return (dpValue * scale + 0.5f); } public static class BannerInfo { public String mImgUrl; public String mTargetUrl; public Object mUserData; public BannerInfo(String img, String url) { this(img, url, null); } public BannerInfo(String img, String url, Object userData) { mImgUrl = img; mTargetUrl = url; mUserData = userData; } } private class BannerAdapter extends PagerAdapter implements View.OnClickListener { private ArrayList mData = new ArrayList<>(); WeakReference mBannerViewWeakReference ; public BannerAdapter(BannerView v) { mBannerViewWeakReference = new WeakReference (v) ; } public void setBannerDatas(ArrayList data) { mData = data; notifyDataSetChanged(); } @Override public int getCount() { return mData.size() > 1 ? 100000000:mData.size(); } @Override public boolean isViewFromObject(View v, Object o) { return v == o; } @Override public void destroyItem(ViewGroup container, int position, Object object) { container.removeView((View) object); } @Override public Object instantiateItem(ViewGroup container, int position) { ImageView iv = new ImageView(container.getContext()); iv.setScaleType(ImageView.ScaleType.CENTER_CROP); iv.setOnClickListener(this); container.addView(iv, -1, -1); BannerInfo info = getItem(position); if ( mBannerViewWeakReference.get() != null ){ mBannerViewWeakReference.get().onShowImage(iv, info.mImgUrl); } return iv; } public BannerInfo getItem(int position) { if (mData.size() < 1) { return null; } return mData.get(position%mData.size()); } @Override public void onClick(View view) { Log.i("aaaa", "onClick"); if ( mBannerViewWeakReference.get() != null ){ mBannerViewWeakReference.get().onItemClick(); } } @Override public int getItemPosition(Object object) { //return super.getItemPosition(object); return POSITION_NONE; } public int getDataPosition(int position) { return position%mData.size(); } } }
用法也比较简单，在XML中直接引用
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="com.penquanyun.datarecover.views.OrderTabFragment">
android:id="@+id/banner"
android:layout_width="match_parent"
android:layout_height="160dp" />
初始化JAVA代码
BannerView bv = (BannerView) view.findViewById(R.id.banner); bv.setBannerViewListener(new BannerView.BannerViewListener() { @Override public void onShowImage(ImageView view, String imgUrl) { BitmapUtils.getInstance().display(getContext(), view, imgUrl, R.drawable.img_banner_default); } @Override public void onItemClick(int position, String targetUrl, Object userData) { } @Override public View onCreateIndicatorView() { ImageView v = new ImageView(getContext()); v.setPadding(10, 0, 0, 0); v.setImageResource(R.drawable.pager_indicator_selector); return v; } }); ArrayListtestData = new ArrayList<>(); testData.add(new BannerView.BannerInfo("http://f11.baidu.com/it/u=918331178,1783361582&fm=72", "")); testData.add(new BannerView.BannerInfo("http://f11.baidu.com/it/u=1678574154,1323011225&fm=72", "")); testData.add(new BannerView.BannerInfo("http://f11.baidu.com/it/u=1678574154,1323011225&fm=72", "")); testData.add(new BannerView.BannerInfo("http://f11.baidu.com/it/u=918331178,1783361582&fm=72", "")); testData.add(new BannerView.BannerInfo("http://f11.baidu.com/it/u=1678574154,1323011225&fm=72", "")); bv.setBannerDatas(testData);
onShowImage会在现实图片等时候调用，根据自己工程中使用的图片库自己实现
onCreateIndicatorView，在创建标签View的时候调用，这里可以自己随便定制
BannerInfo构造函数有多个实现，第一个参数是要显示的图片URL,第二个参数是点击后要跳转的URL，
pager_indicator_selector 是一个资源，这里给个参考
xml version="1.0" encoding="utf-8"?>
xmlns:android="http://schemas.android.com/apk/res/android" >
- android:state_selected="true" android:drawable="@drawable/icon_pager_indicator_selected" />
- android:drawable="@drawable/icon_pager_indicator_normal"/>