【框架】异步加载大量图片--ImageLoader

public abstract class BaseImageLoaderProvider {
    public abstract void loadImage(Context ctx, ImageLoader img);
}

public class GlideImageLoaderCorpProvider extends BaseImageLoaderProvider {
    @Override
    public void loadImage(Context ctx, ImageLoader img) {

        int strategy = img.getStrategy();
        if (strategy == ImageLoaderHelp.LOAD_STRATEGY_ONLY_WIFI) {
            String netType = NetworkStateHelp.getNetWorkModel(App.getApplication());
            //如果是在wifi下才加载图片，并且当前网络是wifi,直接加载
            if (NetworkStateHelp.MODE_WIFI.equals(netType)) {
                loadNormal(ctx, img);
            } else {
                //如果是在wifi下才加载图片，并且当前网络不是wifi，加载缓存
                loadCache(ctx, img);
            }
        } else {
            //如果不是在wifi下才加载图片
            loadNormal(ctx, img);
        }

    }


    /**
     * load image with Glide
     */
    private void loadNormal(Context ctx, ImageLoader img) {
        Glide.with(ctx).load(img.getUrl()).placeholder(img.getPlaceHolder()).centerCrop().into(img.getImgView());
    }


    /**
     * load cache image with Glide
     */
    private void loadCache(Context ctx, ImageLoader img) {
        Glide.with(ctx).using(new StreamModelLoader<String>() {
            @Override
            public DataFetcher<InputStream> getResourceFetcher(final String model, int i, int i1) {
                return new DataFetcher<InputStream>() {
                    @Override
                    public InputStream loadData(Priority priority) throws Exception {
                        throw new IOException();
                    }

                    @Override
                    public void cleanup() {

                    }

                    @Override
                    public String getId() {
                        return model;
                    }

                    @Override
                    public void cancel() {

                    }
                };
            }
        }).load(img.getUrl()).placeholder(img.getPlaceHolder()).diskCacheStrategy(DiskCacheStrategy.ALL).into(img.getImgView());
    }
}

public class GlideImageLoaderProvider extends BaseImageLoaderProvider {
    @Override
    public void loadImage(Context ctx, ImageLoader img) {

        int strategy = img.getStrategy();
        if (strategy == ImageLoaderHelp.LOAD_STRATEGY_ONLY_WIFI) {
            String netType = NetworkStateHelp.getNetWorkModel(App.getApplication());
            //如果是在wifi下才加载图片，并且当前网络是wifi,直接加载
            if (NetworkStateHelp.MODE_WIFI.equals(netType)) {
                loadNormal(ctx, img);
            } else {
                //如果是在wifi下才加载图片，并且当前网络不是wifi，加载缓存
                loadCache(ctx, img);
            }
        } else {
            //如果不是在wifi下才加载图片
            loadNormal(ctx, img);
        }

    }


    /**
     * load image with Glide
     */
    private void loadNormal(Context ctx, ImageLoader img) {
        Glide.with(ctx).load(img.getUrl()).placeholder(img.getPlaceHolder()).into(img.getImgView());
    }


    /**
     * load cache image with Glide
     */
    private void loadCache(Context ctx, ImageLoader img) {
        Glide.with(ctx).using(new StreamModelLoader<String>() {
            @Override
            public DataFetcher<InputStream> getResourceFetcher(final String model, int i, int i1) {
                return new DataFetcher<InputStream>() {
                    @Override
                    public InputStream loadData(Priority priority) throws Exception {
                        throw new IOException();
                    }

                    @Override
                    public void cleanup() {

                    }

                    @Override
                    public String getId() {
                        return model;
                    }

                    @Override
                    public void cancel() {

                    }
                };
            }
        }).load(img.getUrl()).placeholder(img.getPlaceHolder()).diskCacheStrategy(DiskCacheStrategy.ALL).into(img.getImgView());
    }
}

public class ImageLoader {
    private int type;  //类型 (大图，中图，小图)
    private String url; //需要解析的url
    private int placeHolder; //当没有成功加载的时候显示的图片
    private ImageView imgView; //ImageView的实例
    private int strategy;//加载策略，是否在wifi下才加载

    private ImageLoader(Builder builder) {
        this.type = builder.type;
        this.url = builder.url;
        this.placeHolder = builder.placeHolder;
        this.imgView = builder.imgView;
        this.strategy = builder.strategy;
    }
    public int getType() {
        return type;
    }

    public String getUrl() {
        return url;
    }

    public int getPlaceHolder() {
        return placeHolder;
    }

    public ImageView getImgView() {
        return imgView;
    }

    public int getStrategy() {
        return strategy;
    }

    public static class Builder {
        private int type;
        private String url;
        private int placeHolder;
        private ImageView imgView;
        private int strategy;

        public Builder() {
            this.type = ImageLoaderHelp.PIC_SMALL;
            this.url = "";
            this.placeHolder = R.drawable.icon_fmoren;
            this.imgView = null;
            this.strategy = ImageLoaderHelp.LOAD_STRATEGY_NORMAL;
        }

        public Builder type(int type) {
            this.type = type;
            return this;
        }

        public Builder url(String url) {
            this.url = url;
            return this;
        }

        public Builder placeHolder(int placeHolder) {
            this.placeHolder = placeHolder;
            return this;
        }

        public Builder imgView(ImageView imgView) {
            this.imgView = imgView;
            return this;
        }

        public Builder strategy(int strategy) {
            this.strategy = strategy;
            return this;
        }

        public ImageLoader build() {
            return new ImageLoader(this);
        }

    }
}

/**
 * ImageLoader包装类，对外提供接口使用
 */
public class ImageLoaderHelp {

    public static final int PIC_LARGE = 0;
    public static final int PIC_MEDIUM = 1;
    public static final int PIC_SMALL = 2;

    public static final int LOAD_STRATEGY_NORMAL = 0;
    public static final int LOAD_STRATEGY_ONLY_WIFI = 1;

    private static ImageLoaderHelp mInstance;
    private BaseImageLoaderProvider mProvider;
    private BaseImageLoaderProvider mCorpProvider;

    private ImageLoaderHelp() {
        mProvider = new GlideImageLoaderProvider();
        mCorpProvider = new GlideImageLoaderCorpProvider();
    }

    //single instance
    public static ImageLoaderHelp getInstance() {
        if (mInstance == null) {
            synchronized (ImageLoaderHelp.class) {
                if (mInstance == null) {
                    mInstance = new ImageLoaderHelp();
                    return mInstance;
                }
            }
        }
        return mInstance;
    }

    public void loadImage(Context context, ImageLoader img) {
        mProvider.loadImage(context, img);
    }

    public void loadImage(Context context, String uri, ImageView imageView) {
        ImageLoader imageLoader = new ImageLoader.Builder().url(uri).imgView(imageView).build();
        mProvider.loadImage(context, imageLoader);
    }

    public void loadImageCorp(Context context, String uri, ImageView imageView) {
        ImageLoader imageLoader = new ImageLoader.Builder().url(uri).imgView(imageView).build();
        mCorpProvider.loadImage(context, imageLoader);
    }

    public void loadQuestionHeadPic(Context context, String uri, ImageView imageView) {
        ImageLoader imageLoader = new ImageLoader.Builder().placeHolder(R.drawable.moren_tx_tiwenqu).url(uri).imgView(imageView).build();
        mProvider.loadImage(context, imageLoader);
    }

    public void loadLiveroomHeadPic(Context context, String uri, ImageView imageView) {
        ImageLoader imageLoader = new ImageLoader.Builder().placeHolder(R.drawable.moren_tx_liaotianshi).url(uri).imgView(imageView).build();
        mProvider.loadImage(context, imageLoader);
    }

    public void loadLiveroomPic(Context context, String uri, ImageView imageView) {
        ImageLoader imageLoader = new ImageLoader.Builder().placeHolder(R.drawable.img_shibai).url(uri).imgView(imageView).build();
        mProvider.loadImage(context, imageLoader);
    }

    public void loadTopicInfoGuestHeadPic(Context context, String uri, ImageView imageView) {
        ImageLoader imageLoader = new ImageLoader.Builder().placeHolder(R.drawable.moren_tx_jinruzhibojian).url(uri).imgView(imageView).build();
        mProvider.loadImage(context, imageLoader);
    }

    public void loadTopicInfoBannerPic(Context context, String uri, ImageView imageView) {
        ImageLoader imageLoader = new ImageLoader.Builder().placeHolder(R.drawable.banner_zhibo).url(uri).imgView(imageView).build();
        mCorpProvider.loadImage(context, imageLoader);
    }


}

 ImageLoader imageLoader = new ImageLoader.Builder().url(myCourseEntity.getImgUrl()).imgView(myCourseViewHolder.myCourseImage).build();
 ImageLoaderHelp.getInstance().loadImage(context,imageLoader);