@Override
  protected Bitmap doInBackground(Object... params) {
    iv = (ImageView) params[0];
    thumbnailPath = (String) params[1];
    localFullSizePath = (String) params[2];
    ctx = (Context) params[3];
    remotePath = (String) params[4];
    Bitmap result = ImageUtils.decodeScaleImage(localFullSizePath, 160, 160);
    if (result == null && remotePath != null) {
      OSSData avatar = OssManager.getInstance().downLoadData(remotePath);
      try {
        byte[] data = avatar.get();
        if (data != null) {
          result = BitmapFactory.decodeByteArray(data, 0, data.length);
          ImageCache.getInstance().put(localFullSizePath, result);
          result = ImageUtils.decodeScaleImage(localFullSizePath, 160, 160);
        }

      } catch (OSSException e) {
        e.printStackTrace();
        return null;
      }
    }

    return result;
  }
  @Override
  protected void onPostExecute(Bitmap result) {
    if (result != null) {
      iv.setImageBitmap(result);
      ImageCache.getInstance().put(thumbnailPath, result);
      iv.setOnClickListener(
          new OnClickListener() {

            @Override
            public void onClick(View v) {

              if (thumbnailPath != null) {

                Intent intent = new Intent(ctx, ShowBigImgActivity.class);
                File file = new File(localFullSizePath);
                if (file.exists()) {
                  Uri uri = Uri.fromFile(file);
                  intent.putExtra("uri", uri);
                } else {
                  // The local full size pic does not exist yet.
                  // ShowBigImage needs to download it from the server
                  // first
                  intent.putExtra("remotepath", remotePath);
                }
                /*if (message != null && message.direct == EMMessage.Direct.RECEIVE && !message.isAcked) {
                	message.isAcked = true;
                	try {
                		// 看了大图后发个已读回执给对方
                		EMChatManager.getInstance().ackMessageRead(message.getFrom(), message.getMsgId());
                	} catch (Exception e) {
                		e.printStackTrace();
                	}
                }*/
                ctx.startActivity(intent);
              }
            }
          });
    }
  }