我有一个应用程序,我必须下载大量的文件,从400到900个文件,总共大约1GB。在iOS中下载大量文件在后台iOS
哪个是最好的方法来完成这个?
- 其中一个
NSURLSession
和所有的任务排入其中? - 一个
NSURLSession
并按包排队任务(例如10乘10)? - 多个
NSURLSession
不同队列?
其实我在所有任务(每个文件一个)中有一个NSURLSession
排队,但有时我得到Lost connection to background transfer service
。
这里是我的代码:
if([[UIDevice currentDevice] isMultitaskingSupported])
{
__block UIBackgroundTaskIdentifier bgTask;
UIApplication *application = [UIApplication sharedApplication];
bgTask = [application beginBackgroundTaskWithExpirationHandler:^{
[application endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
NSString *uuidString;
CFUUIDRef uuid = CFUUIDCreate(nil);
uuidString = CFBridgingRelease(CFUUIDCreateString(nil, uuid));
CFRelease(uuid);
// }
NSURLSessionConfiguration *sessionConfiguration;
if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"8.0"))
{
sessionConfiguration = [NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier:@"com.fiveflamesmobile.bakgroundDownload"];
}
else
{
sessionConfiguration = [NSURLSessionConfiguration backgroundSessionConfiguration:@"com.fiveflamesmobile.bakgroundDownload"];
}
sessionConfiguration.HTTPMaximumConnectionsPerHost = 5;
sessionConfiguration.sessionSendsLaunchEvents = YES;
sessionConfiguration.discretionary = YES;
sessionConfiguration.timeoutIntervalForResource = 0; //NO timeout
sessionConfiguration.timeoutIntervalForRequest = 0; //No timeout
sessionConfiguration.networkServiceType = NSURLNetworkServiceTypeBackground;
self.session = [NSURLSession sessionWithConfiguration:sessionConfiguration
delegate:self
delegateQueue:nil];
NSLog(@"##### ------- Sesion created succesfully");
// [self batchDownloading];
for (id<FFDownloadFileProtocol> file in self.selectedCatalogProducto.downloadInfo.arrayFiles)
{
[self startDownloadFile:file];
}
NSLog(@"##### ------- Download tasks created successfully ------");
[application endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
});
}
}
'一个NSURLSession和排队的任务由包(10×10为例)? '听起来不错。 – 2014-11-21 13:19:46
@AnoopVaidya你为什么这么说?他应该创建单个后台会话并将其下载任务添加到该会话中。我认为10x10方法没有价值。 – Rob 2014-11-21 13:45:26
你是否可以下载后台的所有文件? – Mahesh 2016-06-03 15:06:17