【iOS】SDWebImage异步下载多张图片保存到相册

self.videoSuffixs = @[@"mov",@"mp4",@"rmvb",@"rm",@"flv",@"avi",@"3gp",@"wmv",@"mpeg1",@"mpeg2",@"mpeg4(mp4)", @"asf",@"swf",@"vob",@"dat",@"m4v",@"f4v",@"mkv",@"mts",@"ts"];
- (void)addLongPress {
    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithActionBlock:^(id  _Nonnull sender) {
        
        @strongify(self);
        NSString *urlString = (NSString *)photo;
        NSString *suffix = [[urlString.lowercaseString componentsSeparatedByString:@"."] lastObject];
        if (suffix && [self.videoSuffixs containsObject:suffix]) {
            [MBProgressHUD showInfoMessage:@"暂不支持视频保存"];
            return;
        }
        
        NSArray *actions;
        if (self.photos.count > 1) {
            actions = @[@"取消", @"保存该图片至相册", @"批量保存至相册"];
        } else {
            actions = @[@"取消", @"保存该图片至相册"];
        }
        
        [self ActionSheetWithTitle:nil message:nil destructive:nil destructiveAction:^(NSInteger index) {
            DLog(@"destructiveAction = %ld", index);
        } andOthers:actions animated:YES action:^(NSInteger index) {
            DLog(@"action = %ld", index);
            DLog(@"photo = %@", photo);
            DLog(@"photos = %@", self.photos);
            if (index == 0) {
                // 取消
                
            } else if (index == 1) {
                // 保存该图片至相册
                self->_isSaveMultiPhotos = NO;
                SDImageCache *imageCache = [SDImageCache sharedImageCache];
                UIImage *image = [imageCache imageFromCacheForKey:photo];
                [self saveImgAsync:image];
            } else if (index == 2) {
                // 批量保存至相册
                self->_isSaveMultiPhotos = YES;
                [self saveImgsAsync:self.photos];
            }
        }];
        
    }];
    [cell addGestureRecognizer:longPress];
}

- (void)saveImgsAsync:(NSArray *)photos {
    
    [MBProgressHUD showInfoMessage:@"正在保存"];
    if(photos.count>0) {
        
        dispatch_group_t group = dispatch_group_create();
        
        for (NSString *photo in photos) {
            dispatch_group_enter(group);
            
            NSURL *url = [NSURL URLWithString:photo];
            [[SDWebImageDownloader sharedDownloader] downloadImageWithURL:url options:0 progress:nil completed:^(UIImage * _Nullable image, NSData * _Nullable data, NSError * _Nullable error, BOOL finished) {
                
                [self saveImgAsync:image];
                
                dispatch_group_leave(group);
                
            }];
        }
        
        dispatch_group_notify(group, dispatch_get_main_queue(), ^{
            [MBProgressHUD showInfoMessage:@"图片已保存到相册"];
        });
    }
    
}

- (void)saveImgAsync:(UIImage *)img
{
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        UIImageWriteToSavedPhotosAlbum(img, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
    });
}

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
    if (_isSaveMultiPhotos == NO) {
        dispatch_async(dispatch_get_main_queue(), ^{
            if (error) {
                [MBProgressHUD showErrorMessage:@"图片保存失败"];
            } else {
                [MBProgressHUD showSuccessMessage:@"图片已保存到相册"];
            }
        });
    }
}