SDWebImage的block使用

SDWebImageManager *sSDWebImageManager sharedManager];
 

 UIImage *cachedImage = [sdManager imageWithUrl:url];// 将需要缓存的图片加载进来
        //如果缓存中有图片
        if (cachedImage) {
            MYLog(@"有缓存图片");
           
            [button setBackgroundImage:cachedImage forState:UIControlStateNormal];
        }else
        {
         //如果缓存中没有图片，异步下载图片
            MYLog(@"正在下载图片%@",url);
            [sdManager downloadWithURL:url options:0 progress:^(NSUInteger receivedSize, long long expectedSize) {
                
            } completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished) {
                if (image) {
                    MYLog(@"下载完成的图片");
                    [button setBackgroundImage:image forState:UIControlStateNormal];
                }
            }];
        }