android universal-image-loader的使用

全局配置 android-image-loader

public class Application extends Application {  
  
    @Override  
    public void onCreate() {  
        super.onCreate();  
        initImageLoader(getApplicationContext());  
    }  
  
    public static void initImageLoader(Context context) {  
        //缓存文件的目录  
        File cacheDir = StorageUtils.getOwnCacheDirectory(context, "universalimageloader/Cache");   
        ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(context)  
                .memoryCacheExtraOptions(480, 800) // max width, max height，即保存的每个缓存文件的最大长宽   
                .threadPoolSize(3) //线程池内线程的数量  
                .threadPriority(Thread.NORM_PRIORITY - 2)  
                .denyCacheImageMultipleSizesInMemory()  
                .diskCacheFileNameGenerator(new Md5FileNameGenerator()) //将保存的时候的URI名称用MD5 加密  
                .memoryCache(new UsingFreqLimitedMemoryCache(2 * 1024 * 1024))  
                .memoryCacheSize(2 * 1024 * 1024) // 内存缓存的最大值  
                .diskCacheSize(50 * 1024 * 1024)  // SD卡缓存的最大值  
                .tasksProcessingOrder(QueueProcessingType.LIFO)  
                // 由原先的discCache -> diskCache  
                .diskCache(new UnlimitedDiscCache(cacheDir))//自定义缓存路径    
                .imageDownloader(new BaseImageDownloader(context, 5 * 1000, 30 * 1000)) // connectTimeout (5 s), readTimeout (30 s)超时时间    
                .writeDebugLogs() // Remove for release app  
                .build();  
        //全局初始化此配置    
        ImageLoader.getInstance().init(config);  
    }  
} 

 2）使用方式

 

    public class MainActivity extends Activity {  
        private ImageLoader imageLoader;  
        private ListView lv;  
        private String[] imageUrls;  
        private DisplayImageOptions options;  
      
        @Override  
        protected void onCreate(Bundle savedInstanceState) {  
            super.onCreate(savedInstanceState);  
            setContentView(R.layout.activity_main);  
            imageLoader = ImageLoader.getInstance();  
            lv = (ListView)findViewById(R.id.list);  
              
            imageUrls = Constants.images;  
      
            // 使用DisplayImageOptions.Builder()创建DisplayImageOptions  
            options = new DisplayImageOptions.Builder()  
                    .showImageOnLoading(R.drawable.ic_stub) // 设置图片下载期间显示的图片  
                    .showImageForEmptyUri(R.drawable.ic_empty) // 设置图片Uri为空或是错误的时候显示的图片  
                    .showImageOnFail(R.drawable.ic_error) // 设置图片加载或解码过程中发生错误显示的图片  
                    .cacheInMemory(true) // 设置下载的图片是否缓存在内存中  
                    .cacheOnDisk(true) // 设置下载的图片是否缓存在SD卡中  
                    .displayer(new RoundedBitmapDisplayer(20)) // 设置成圆角图片  
                    .build(); // 构建完成  
            lv.setAdapter(new ItemListAdapter());  
        }  
      
        @Override  
        public boolean onCreateOptionsMenu(Menu menu) {  
            // Inflate the menu; this adds items to the action bar if it is present.  
            getMenuInflater().inflate(R.menu.main, menu);  
            return true;  
        }  
      
        @Override  
        public boolean onOptionsItemSelected(MenuItem item) {  
            switch (item.getItemId()) {  
                case R.id.item_clear_memory_cache:  
                    ImageLoader.getInstance().clearMemoryCache();  
                    return true;  
                case R.id.item_clear_disc_cache:  
                    ImageLoader.getInstance().clearDiskCache();  
                    return true;  
                default:  
                    return false;  
            }  
        }  
      
        class ItemListAdapter extends BaseAdapter {  
            @Override  
            public int getCount() {  
                // TODO Auto-generated method stub  
                return imageUrls.length;  
            }  
      
            @Override  
            public Object getItem(int position) {  
                // TODO Auto-generated method stub  
                return imageUrls[position];  
            }  
      
            @Override  
            public View getView(int position, View convertView, ViewGroup parent) {  
                // TODO Auto-generated method stub  
                ViewHolder holder = null;  
                if (convertView == null) {  
                    convertView = getLayoutInflater().inflate(R.layout.item_list, parent, false);  
                    holder = new ViewHolder();  
                    holder.text = (TextView) convertView.findViewById(R.id.text);  
                    holder.image = (ImageView) convertView.findViewById(R.id.image);  
                    convertView.setTag(holder);  
                } else {  
                    holder = (ViewHolder) convertView.getTag();  
                }  
                holder.text.setText("Item " + (position + 1));  
                imageLoader.displayImage(imageUrls[position], holder.image, options);  
                return convertView;  
            }  
      
            @Override  
            public long getItemId(int position) {  
                // TODO Auto-generated method stub  
                return position;  
            }  
      
            class ViewHolder {  
                public ImageView image;  
                public TextView text;  
            }  
        }  
      
    }