NSURLSession 委托方法未调用

我创建了一个非常简单的应用程序来从我的网络服务器下载文本文件。我可以与 NSURLConnection 完美配合，但我正在尝试迁移到 NSURLSession。

我遇到的问题是没有调用任何委托方法。

我的服务器受密码保护，因此我需要使用基本的 http 身份验证来访问该文件，但是当 didReceiveChallenge 方法从未被调用时。

代码行 [getFileTaskresume] 似乎对任何事情都没有影响。

我的设置如下：

@interface ViewController : UIViewController <NSURLSessionDelegate, NSURLSessionDownloadDelegate, NSURLSessionTaskDelegate>
{
   NSURLSession *session;
}

从 viewDidLoad 调用以下方法：

-(void)setUpTheNetworking
{
    NSString *fileURL = @"www.mywebsite.com/utility/file.txt";

    NSURLSessionConfiguration *sessionConfig = [NSURLSessionConfiguration defaultSessionConfiguration];
    sessionConfig.allowsCellularAccess = YES;
    sessionConfig.timeoutIntervalForRequest = 10;
    sessionConfig.timeoutIntervalForResource = 10;
    sessionConfig.HTTPMaximumConnectionsPerHost = 1;

    session = [NSURLSession sessionWithConfiguration:sessionConfig delegate:self delegateQueue:nil];

    NSURLSessionDownloadTask *getFileTask = [session downloadTaskWithURL:[NSURL URLWithString:fileURL]];

    [getFileTask resume];
}

我实现的委托方法是：

-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite
{
    NSLog(@"Here we go");
}

-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didResumeAtOffset:(int64_t)fileOffset expectedTotalBytes:(int64_t)expectedTotalBytes
{
    NSLog(@"Here we go");
}

-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location
{
    NSLog(@"Here we go");
}

- (void)URLSession:(NSURLSession *)session didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential *credential))completionHandler
{
   if (challenge.previousFailureCount == 0)
   {
       NSURLCredentialPersistence persistence = NSURLCredentialPersistenceForSession;
       NSURLCredential *credential = [NSURLCredential credentialWithUser:user password:@password persistence:persistence];
       completionHandler(NSURLSessionAuthChallengeUseCredential, credential);
   }
   else
   {
       // handle the fact that the previous attempt failed
       NSLog(@"%s: challenge.error = %@", __FUNCTION__, challenge.error);
       completionHandler(NSURLSessionAuthChallengeCancelAuthenticationChallenge, nil);
   }
}

 - (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task
   didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge
   completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential *credential))completionHandler
{
    {
        if (challenge.previousFailureCount == 0)
        {
             NSURLCredential *credential = [NSURLCredential  credentialWithUser:user password:password persistence:NSURLCredentialPersistenceForSession];
        completionHandler(NSURLSessionAuthChallengeUseCredential, credential);
        }
        else
        {
            NSLog(@"%s; challenge.error = %@", __FUNCTION__, challenge.error);
            completionHandler(NSURLSessionAuthChallengeCancelAuthenticationChallenge, nil);
        }

    }
}

Thanks!

SOLVED!

以下代码行是罪魁祸首：

 NSString *fileURL = @"www.mywebsite.com/utility/file.txt";

原来它也需要 http:// 在那里，所以这个有效

 NSString *fileURL = @"http://www.mywebsite.com/utility/file.txt";

我仍然觉得很奇怪，它不起作用。我原以为会弹出一个错误。