无法在NSURLSession中使用自定义委托

Question

我有一个NSURLconnection实现，正在尝试迁移到IOS-9的NSURlsession。

NSURLconnection实现：

@property (nonatomic, strong, readwrite) NSURLConnection *  connection;    

自定义委托方法：

-(BOOL)connection:(NSURLConnection *)connection ---canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace*)protectionSpace   
-(void)connection:(NSURLConnection *)connection  didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge  
- (void)connection:(NSURLConnection *)conn didReceiveResponse:(NSURLResponse *)aresponse  
-(void)connection:(NSURLConnection *)conn didReceiveData:(NSData *)data  
- (void)connectionDidFinishLoading:(NSURLConnection *)conn
- (void)connection:(NSURLConnection *)theConnection didFailWithError:(NSError*)error  

self.connection = [NSURLConnection connectionWithRequest:request delegate:self];

现在，当我将上面的impl修改为基于NSURLsession的impl时，我现在有了

@property (nonatomic, strong, readwrite) NSURLSession *session;  

自定义委托方法：

- (BOOL)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace*)protectionSpace  
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge  
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didReceiveResponse:(NSURLResponse *)aresponse  
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didReceiveData:(NSData *)data   
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task connectionDidFinishLoading:(NSURLConnection *)conn  
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didFailWithError:(NSError *)error  


NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration    defaultSessionConfiguration];
self.session = [NSURLSession sessionWithConfiguration:configuration                                                                  delegate:self                                                                    delegateQueue: nil];
NSURLSessionDataTask *task = [self.session dataTaskWithRequest:request];
[task resume]; 

在这之后，我得到了如下的编译错误：

./../source/smmacosx/smplt.m:663:33: error: sending     'SmHttpsAuthenticationHandler *' to parameter of incompatible type 'id<NSURLSessionDelegate> _Nullable' [-Werror]

                                                                                                                           delegate: self

                                                                                                                                   ^~~~

 /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS9.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSURLSession.h:135:132: note: 

      passing argument to parameter 'delegate' here

 + (NSURLSession *)sessionWithConfiguration:(NSURLSessionConfiguration   *)configuration delegate:(nullable id <NSURLSessionDelegate>)delegate delegateQueue:(nullable NSOperati...

我不能理解为什么NSURLSession Impl中的delegate=self会抛出这样的错误？SmHttpsAuthenticationHandler是一个接口，定义为

 @interface SmHttpsAuthenticationHandler: NSObject{....} and then   @implementation SmHttpsAuthenticationHandler

请在NSURLSession实现上给出任何指示。非常感谢。

Answer 1

在您的接口声明中，您需要声明您的类符合NSURLSessionDelegate协议，例如

@接口SmHttpsAuthenticationHandler : NSObject