輪播網絡圖片加載適配

public class MeasureUtil {

    /**
     * 獲取狀態欄的高度
     */
    public static int getStatusBarHeight(Context context) {
        int result = 0;
        int resourceId = context.getResources().getIdentifier("status_bar_height", "dimen", "android");
        if (resourceId > 0) {
            result = context.getResources().getDimensionPixelSize(resourceId);
        }
        return result;
    }
    /**
     * 獲取導航欄的高度
     */
    public static int getNavigationBarHeight(Context context) {
        int result = 0;
        int resourceId = context.getResources().getIdentifier("navigation_bar_height", "dimen", "android");
        if (resourceId > 0) {
            result = context.getResources().getDimensionPixelSize(resourceId);
        }
        return result;
    }
    
    /**
     * 獲取屏幕尺寸
     */
    public static Point getScreenSize(Context context) {
        // 獲取屏幕寬高
        WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        Point screenSize = new Point();
        wm.getDefaultDisplay().getSize(screenSize);
        return screenSize;
    }

    /**
     * 根據手機的分辨率從 dp 的單位 轉成爲 px(像素)
     */
    public static int dip2px(Context context, float dpValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }

    /**
     * 根據手機的分辨率從 px(像素) 的單位 轉成爲 dp
     */
    public static int px2dip(Context context, float pxValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (pxValue / scale + 0.5f);
    }

    /**
     * 將px值轉換爲sp值，保證文字大小不變
     */
    public static int px2sp(Context context, float pxValue) {
        final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
        return (int) (pxValue / fontScale + 0.5f);
    }

    /**
     * 將sp值轉換爲px值，保證文字大小不變
     */
    public static int sp2px(Context context, float spValue) {
        final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
        return (int) (spValue * fontScale + 0.5f);
    }

    /**
     * 百分比轉換爲實際的像素值（寬度）
     */
    public static int per2px(Resources res, double per) {
        if (null == res) {
            return 0;
        }
        if (per < 0 || per > 1) {
            return 0;
        }
        DisplayMetrics dm = res.getDisplayMetrics();
        return (int) Math.ceil(dm.widthPixels * per);
    }

}

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佈局代碼：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
             android:orientation="vertical"
             android:layout_width="match_parent"
             android:layout_height="match_parent">

    <android.support.v4.view.ViewPager
        android:id="@+id/adv_pager"
        android:layout_width="match_parent"
        android:layout_height="256dp" />

    <RelativeLayout
        android:layout_gravity="bottom"
        android:layout_width="match_parent"
        android:layout_height="30dp">
        <LinearLayout
            android:layout_centerHorizontal="true"
            android:id="@+id/viewGroup"
            android:layout_width="wrap_content"
            android:layout_centerVertical="true"
            android:gravity="center_horizontal"
            android:orientation="horizontal"
            android:layout_height="wrap_content" />
    </RelativeLayout>

</FrameLayout>

自定義View:

public class BannerView extends LinearLayout {
    /**
     * 上下文
     */
    private Context mContext;
    /**
     * 圖片輪播視圖
     */
    private ViewPager mAdvPager = null;

    /**
     * 滾動圖片視圖適配器
     */
    private ImageCycleAdapter mAdvAdapter;

    /**
     * 圖片輪播指示器控件
     */
    private LinearLayout mGroup;

    /**
     * 圖片輪播指示器-個圖
     */
    private ImageView mImageView = null;

    /**
     * 滾動圖片指示器-視圖列表
     */
    private ImageView[] mImageViews = null;

    /**
     * 圖片滾動當前圖片下標
     */
    private int mImageIndex = 0;


    /**
     * @param context
     */
    public BannerView(Context context) {
        super(context);
    }

    /**
     * @param context
     * @param attrs
     */
    public BannerView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        LayoutInflater.from(context).inflate(R.layout.banner_layout, this);
        mAdvPager = (ViewPager) findViewById(R.id.adv_pager);
        mAdvPager.addOnPageChangeListener(new GuidePageChangeListener());
        mAdvPager.setOnTouchListener(new OnTouchListener() {

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                switch (event.getAction()) {
                    case MotionEvent.ACTION_UP:
                        // 開始圖片滾動
                        startImageTimerTask();
                        break;
                    default:
                        // 停止圖片滾動
                        stopImageTimerTask();
                        break;
                }
                return false;
            }
        });
        // 滾動圖片右下指示器視圖
        mGroup = (LinearLayout) findViewById(R.id.viewGroup);
    }

    /**
     * 設置圖片數據源
     * @param imageUrlList 圖片集合(數據類型：String->URL or  Integer->ResourceID)
     * @param imageCycleViewListener
     */
    public void setImageResources(ArrayList<Object> imageUrlList, ImageCycleViewListener imageCycleViewListener) {
        // 清除所有子視圖
        mGroup.removeAllViews();
        // 圖片廣告數量
        final int imageCount = imageUrlList.size();
        mImageViews = new ImageView[imageCount];
        for (int i = 0; i < imageCount; i++) {
            mImageView = new ImageView(mContext);
            int imageParams = MeasureUtil.dip2px(mContext,7);// XP與DP轉換，適應不同分辨率
            int imagePadding = MeasureUtil.dip2px(mContext,5);
            LinearLayout.LayoutParams lp = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
            lp.width = imageParams;
            lp.height = imageParams;

            mImageViews[i] = mImageView;
            if (i == 0) {
                mImageViews[i].setBackgroundResource(R.drawable.point_enable);
            } else {
                lp.leftMargin = imagePadding;
                mImageViews[i].setBackgroundResource(R.drawable.point_disable);
            }
            mGroup.addView(mImageViews[i], i, lp);
        }
        mAdvAdapter = new ImageCycleAdapter(mContext, imageUrlList, imageCycleViewListener);
        if(imageCount>1){
            mImageIndex=100*imageCount;
        }
        mAdvPager.setAdapter(mAdvAdapter);
        mAdvPager.setCurrentItem(mImageIndex,false);
        startImageTimerTask();
    }

    /**
     * 開始輪播(手動控制自動輪播與否，便於資源控制)
     */
    public void startImageCycle() {
        startImageTimerTask();
    }

    /**
     * 暫停輪播——用於節省資源
     */
    public void pushImageCycle() {
        stopImageTimerTask();
    }

    /**
     * 開始圖片滾動任務
     */
    private void startImageTimerTask() {
        stopImageTimerTask();
        // 圖片每3秒滾動一次
        mHandler.postDelayed(mImageTimerTask, 3000);
    }

    /**
     * 停止圖片滾動任務
     */
    private void stopImageTimerTask() {
        mHandler.removeCallbacks(mImageTimerTask);
    }

    private Handler mHandler = new Handler();

    /**
     * 圖片自動輪播Task
     */
    private Runnable mImageTimerTask = new Runnable() {

        @Override
        public void run() {
            if (mImageViews != null) {
                mAdvPager.setCurrentItem(++mImageIndex);
            }
        }
    };

    /**
     * 輪播圖片狀態監聽器
     *
     * @author minking
     */
    private final class GuidePageChangeListener implements ViewPager.OnPageChangeListener {


        @Override
        public void onPageScrollStateChanged(int state) {
        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {
        }


        @Override
        public void onPageSelected(int index) {
            mImageIndex =index;
            index=index%mAdvAdapter.getmAdList().size();
            startImageTimerTask(); // 開始下次計時
            // 設置圖片滾動指示器背景
            for (int i = 0; i < mImageViews.length; i++) {
                if (index == i) {
                    mImageViews[i].setBackgroundResource(R.drawable.point_enable);
                }else{
                    mImageViews[i].setBackgroundResource(R.drawable.point_disable);
                }
            }
        }
    }

    private class ImageCycleAdapter extends PagerAdapter {

        /**
         * 圖片資源列表
         */
        private ArrayList<Object> mAdList = new ArrayList<>();

        /**
         * 廣告圖片點擊監聽器
         */
        private ImageCycleViewListener mImageCycleViewListener;

        private Context mContext;

        public ImageCycleAdapter(Context context, ArrayList<Object> adList, ImageCycleViewListener imageCycleViewListener) {
            mContext = context;
            mAdList = adList;
            mImageCycleViewListener = imageCycleViewListener;

        }

        @Override
        public int getCount() {
            if (mAdList != null) {
                if (mAdList.size() > 1) {
                    return Integer.MAX_VALUE;
                } else {
                    return mAdList.size();
                }
            }
            return 0;

        }

        @Override
        public boolean isViewFromObject(View view, Object obj) {
            return view == obj;
        }

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            position = position % mAdList.size();
            Object item = mAdList.get(position);

            ImageView imageView = new ImageView(mContext);
            imageView.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
            imageView.setScaleType(ImageView.ScaleType.FIT_XY);

            // 設置圖片點擊監聽
            final int finalPosition = position;
            imageView.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    mImageCycleViewListener.onImageClick(finalPosition, v);
                }
            });

            imageView.setOnTouchListener(new OnTouchListener() {

                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    switch (event.getAction()) {
                        // 停止輪播
                        case MotionEvent.ACTION_DOWN:
                            stopImageTimerTask();
                            break;
                        // 開始輪播
                        case MotionEvent.ACTION_UP:
                            startImageTimerTask();
                            break;
                        default:
                            startImageTimerTask();
                            break;
                    }
                    return false;
                }
            });
            container.addView(imageView);
            mImageCycleViewListener.displayImage(item, imageView);

            return imageView;
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            ImageView view = (ImageView) object;
            container.removeView(view);

        }

        public ArrayList<Object> getmAdList() {
            return mAdList;
        }
    }

    /**
     * 輪播控件的監聽事件
     */
    public interface ImageCycleViewListener {

        /**
         * 加載圖片資源
         */
        void displayImage(Object imageURL, ImageView imageView);

        /**
         * 單擊圖片事件
         */
        void onImageClick(int position, View imageView);
    }
}

應用：

佈局引用自定義View。。

MainActivity代碼：

setContentView(R.layout.activity_pro_detail);
BannerAdapterView bannerAdapterView = (BannerAdapterView) findViewById(R.id.banada_view); 
ArrayList<Object> list=new ArrayList<>();
list.add(R.drawable.p2);
list.add(R.drawable.p3);
list.add("");  //網絡加載
list.add(AppConfig.PROJECT + mDetail.getImage());//這個也是網絡加載,Retrofit請求到實體類後運用到輪播
bannerAdapterView.setImageResources(list, new BannerAdapterView.ImageCycleViewListener() {
    @Override
    public void displayImage(Object imageURL, ImageView imageView) {
        if (imageURL instanceof String) {
            //String類型的字符串，網絡url 採用Glide或者picasso框架加載
            Glide.with(WtuActivity.this).load((String) imageURL).into(imageView);
        } else if (imageURL instanceof Integer) {
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            //int類型數據 resource id
            imageView.setImageResource((Integer) imageURL);
        }
    }

    @Override
    public void onImageClick(int position, View imageView) {//點擊事件

    }
});