ios - 从 URL 获取图像在手表应用中花费了太多时间

Question

我正在从 URL 获取图像以将其设置为手表应用程序中 WKInterfaceGroup 的背景图像，但加载背景图像需要太多时间（大约 20 秒），我似乎使用了最首选的方法，但我我无法弄清楚为什么加载图像需要这么长时间......以下是我的代码：

   -(void) watchData:(WatchJSONParser *)data
    {
        int type = (int)data.sourceType;
      watchUserData = data.watchDataDict;

        NSLog(@"watchUserData:%@", watchUserData);
        switch (type)
        {
            case DataConnectionSourceTypeUserData:
                if([watchUserData objectForKey:@"userData"])

                {

                    skpImgServerUrl = [[watchUserData objectForKey:@"userData"] objectForKey:@"imageServerURL"];

                dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0),
                               ^{
                        NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"%@%@",skpImgServerUrl,[[watchUserData objectForKey:@"userData"] objectForKey:@"tenantLogo"]]];
                        NSData *data = [NSData dataWithContentsOfURL:url];

                      NSLog(@"ASY thread:%@", url);
                        dispatch_async(dispatch_get_main_queue(), ^{
                          //[self.homeBgGroup setBackgroundImage:placeholder];
                      [self.homeBgGroup setBackgroundImageData:data];
                            [statusLabel setHidden:YES];


                        });
                    });

                }
                break;
            default:
                break;
        }
    }