在android项目中，最学用的是png格式的图片，或者用jpeg的图片。那我们要用动画类型图片gif格式图片应该怎么办呢？我们可以使用android-gif-drawable框架来实现gif图片加载，下面直接贴下我在项目中用到的工具类：

public class GifLoader {  /**保存图片引用的Map*/  public static Map<ImageView, String> mImageViewMap = Collections.synchronizedMap(new HashMap<ImageView, String>());  private ExecutorService executorService;  /**缓存大小10MiB*/  private static int mMemCacheMaxSize = 10 * 1024 * 1024;  /**LruCache缓存图片*/  private static LruCache<String, byte[]> mMemLruCache;  /**版本号*/  private static int mAppVersion = 1;  /**硬盘缓存50M*/  private static int mDiskCacheMaxSize = 50 * 1024 * 1024;  /**硬盘缓存对象*/  private static DiskLruCache mDiskLruCache;  /**是否要初始化*/  private static boolean mCacheInit = false;  private static final int DISK_CACHE_COUNT = 1;  /**GifLoader对象*/  private static GifLoader loader;  /**默认一张图片的id*/  final int default_image_id = R.drawable.icon_app_normal;      /**构造对象*/  private GifLoader(Context context) {  executorService = Executors.newFixedThreadPool(2);  initCaches(context);  }      /**单例模式*/  public synchronized static GifLoader getInstance(Context context) {  if (loader == null) {  loader = new GifLoader(context);  }  return loader;  }      /**在控件上展示图片*/  public void displayImage(String url, GifImageView imageView, boolean isGif) {  try {  if (new File(url).exists()) {  imageView.setImageDrawable(new GifDrawable(url));  return;  }  }  catch (Exception e) {  }      mImageViewMap.put(imageView, url);  byte[] data = mMemLruCache.get(url);  if (data != null) {  try {  imageView.setImageDrawable(new GifDrawable(data));  }  catch (Exception e) {  e.printStackTrace();  imageView.setImageResource(default_image_id);  }  }  else {  queuePhoto(url, imageView);  imageView.setImageResource(default_image_id);  }      }      private void queuePhoto(String url, GifImageView imageView) {  PhotoToLoad photoToLoad = new PhotoToLoad(url, imageView);  executorService.submit(new PhotosLoader(photoToLoad));  }      /**此方法待优化以防止内存溢出 先从文件里面读取，没有的话再到网上下载*/  private byte[] getBitmap(String url) {  Snapshot cacheEntry = null;  try {  cacheEntry = mDiskLruCache.get(CacheHelper.UriToDiskLruCacheString(url));  }  catch (Exception e) {  e.printStackTrace();  }      byte[] image = null;      if (cacheEntry != null) {  image = inputStreamToByteArray(cacheEntry.getInputStream(0), (int) cacheEntry.getLength(0));  mMemLruCache.put(url, image);  }  try {  if (image != null) {      return image;  }  else {  URL imageUrl = new URL(url);  HttpURLConnection con = (HttpURLConnection) imageUrl.openConnection();  con.setConnectTimeout(30000);  con.setReadTimeout(30000);  con.setInstanceFollowRedirects(true);  InputStream is = con.getInputStream();  image = inputStreamToByteArray(is, 8096);  if (image != null) {      try {  Editor editor = mDiskLruCache.edit(CacheHelper.UriToDiskLruCacheString(url));  if (editor != null) {  if (CacheHelper.writeByteArrayToEditor(image, editor)) {  mDiskLruCache.flush();  editor.commit();  }  else {  editor.abort();  }  }  }  catch (Exception e) {  e.printStackTrace();  }      mMemLruCache.put(url, image);  }  }      }  catch (FileNotFoundException e) {  e.printStackTrace();  }  catch (MalformedURLException e) {  e.printStackTrace();  }  catch (IOException e) {  e.printStackTrace();  }      return image;  }      private class PhotosLoader implements Runnable {  private PhotoToLoad photoToLoad;      public PhotosLoader(PhotoToLoad photoToLoad) {  super();  this.photoToLoad = photoToLoad;  }      @Override  public void run() {  /**下载前检查imageview是否被复用*/  if (imageViewReused(photoToLoad)) { return; }  byte[] bm = getBitmap(photoToLoad.url);      /**下载完毕后再次检查imageview是否被复用*/  if (imageViewReused(photoToLoad)) { return; }  DisplayImageRunnable displayImageRunnable = new DisplayImageRunnable(bm, photoToLoad);  Activity a = (Activity) photoToLoad.imageView.getContext();  a.runOnUiThread(displayImageRunnable);      }      }      boolean imageViewReused(PhotoToLoad photoToLoad) {  String tag = mImageViewMap.get(photoToLoad.imageView);  /**代表imageviews map中存放的imageview对应的value值已经被覆盖掉，也就是重用了*/  if (tag == null || !tag.equals(photoToLoad.url)) {  return true;  }  else {  return false;  }      }      private class DisplayImageRunnable implements Runnable {  private byte[] data;  private PhotoToLoad photoToLoad;      public DisplayImageRunnable(byte[] data, PhotoToLoad photoToLoad) {  super();  this.data = data;  this.photoToLoad = photoToLoad;  }      @Override  public void run() {  if (imageViewReused(photoToLoad)) { return; }  if (data != null) {  try {  photoToLoad.imageView.setImageDrawable(new GifDrawable(data));  }  catch (Exception e) {  e.printStackTrace();  photoToLoad.imageView.setImageResource(default_image_id);  }  }  else {  photoToLoad.imageView.setImageResource(default_image_id);  }      }  }      private class PhotoToLoad {  public String url;  public GifImageView imageView;      public PhotoToLoad(String url, GifImageView imageView) {  super();  this.url = url;  this.imageView = imageView;  }      }      private void initCaches(Context context) {  if (!mCacheInit) {  mMemLruCache = new LruCache<String, byte[]>(mMemCacheMaxSize) {  protected int sizeOf(String key, byte[] value) {  return value.length;  }  };  File diskCacheDir = CacheHelper.getDiskCacheDir(context, "imagecache");  try {  mDiskLruCache = DiskLruCache.open(diskCacheDir, mAppVersion, DISK_CACHE_COUNT, mDiskCacheMaxSize);  }  catch (IOException ignored) {  }  mCacheInit = true;  }  }      private byte[] inputStreamToByteArray(InputStream is, int size) {  ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();  byte[] buffer = new byte[size];      int len = 0;  try {  while ((len = is.read(buffer)) != -1) {  byteBuffer.write(buffer, 0, len);  }  }  catch (IOException e) {  e.printStackTrace();  }      buffer = byteBuffer.toByteArray();  return buffer;  }  }