NSURLConnection 过期

1、NSURLConnection 使用NSURLSession代替 不常用了， 还是需要了解一下

// 几个初始化的方式
- (nullable instancetype)initWithRequest:(NSURLRequest *)request delegate:(nullable id)delegate startImmediately:(BOOL)startImmediately API_DEPRECATED("Use NSURLSession (see NSURLSession.h)", macos(10.5,10.11), ios(2.0,9.0), tvos(9.0,9.0)) API_UNAVAILABLE(watchos);

- (nullable instancetype)initWithRequest:(NSURLRequest *)request delegate:(nullable id)delegate API_DEPRECATED("Use NSURLSession (see NSURLSession.h)", macos(10.3,10.11), ios(2.0,9.0), tvos(9.0,9.0)) API_UNAVAILABLE(watchos);
+ (nullable NSURLConnection*)connectionWithRequest:(NSURLRequest *)request delegate:(nullable id)delegate API_DEPRECATED("Use NSURLSession (see NSURLSession.h)", macos(10.3,10.11), ios(2.0,9.0), tvos(9.0,9.0)) API_UNAVAILABLE(watchos);

// 原来的请求
@property (readonly, copy) NSURLRequest *originalRequest API_AVAILABLE(macos(10.8), ios(5.0), watchos(2.0), tvos(9.0));
// 现在的请求， 有可能会替换掉请求
@property (readonly, copy) NSURLRequest *currentRequest API_AVAILABLE(macos(10.8), ios(5.0), watchos(2.0), tvos(9.0));

// 开始与取消
- (void)start API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
- (void)cancel;

// 取消的request 
+ (BOOL)canHandleRequest:(NSURLRequest *)request; 


- (void)scheduleInRunLoop:(NSRunLoop *)aRunLoop forMode:(NSRunLoopMode)mode API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
- (void)unscheduleFromRunLoop:(NSRunLoop *)aRunLoop forMode:(NSRunLoopMode)mode API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
- (void)setDelegateQueue:(nullable NSOperationQueue*) queue API_AVAILABLE(macos(10.7), ios(5.0), watchos(2.0), tvos(9.0));

> 连接的基本代理回调
@protocol NSURLConnectionDelegate <NSObject>
@optional
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error;
- (BOOL)connectionShouldUseCredentialStorage:(NSURLConnection *)connection;
- (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge;
- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace API_DEPRECATED("Use -connection:willSendRequestForAuthenticationChallenge: instead.", macos(10.6,10.10), ios(3.0,8.0), watchos(2.0,2.0), tvos(9.0,9.0));
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge API_DEPRECATED("Use -connection:willSendRequestForAuthenticationChallenge: instead.", macos(10.2,10.10), ios(2.0,8.0), watchos(2.0,2.0), tvos(9.0,9.0));
- (void)connection:(NSURLConnection *)connection didCancelAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge API_DEPRECATED("Use -connection:willSendRequestForAuthenticationChallenge: instead.", macos(10.2,10.10), ios(2.0,8.0), watchos(2.0,2.0), tvos(9.0,9.0));
@end

请求数据的回调
API_AVAILABLE(macos(10.2), ios(2.0), watchos(2.0), tvos(9.0))
@protocol NSURLConnectionDataDelegate <NSURLConnectionDelegate>
@optional
- (nullable NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(nullable NSURLResponse *)response;
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response;

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data;

- (nullable NSInputStream *)connection:(NSURLConnection *)connection needNewBodyStream:(NSURLRequest *)request;
- (void)connection:(NSURLConnection *)connection   didSendBodyData:(NSInteger)bytesWritten
                                                 totalBytesWritten:(NSInteger)totalBytesWritten
                                         totalBytesExpectedToWrite:(NSInteger)totalBytesExpectedToWrite;

- (nullable NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse;

- (void)connectionDidFinishLoading:(NSURLConnection *)connection;
@end

@protocol NSURLConnectionDownloadDelegate <NSURLConnectionDelegate>
@optional
- (void)connection:(NSURLConnection *)connection didWriteData:(long long)bytesWritten totalBytesWritten:(long long)totalBytesWritten expectedTotalBytes:(long long) expectedTotalBytes;
- (void)connectionDidResumeDownloading:(NSURLConnection *)connection totalBytesWritten:(long long)totalBytesWritten expectedTotalBytes:(long long) expectedTotalBytes;

@required
- (void)connectionDidFinishDownloading:(NSURLConnection *)connection destinationURL:(NSURL *) destinationURL;
@end

 同步请求
+ (nullable NSData *)sendSynchronousRequest:(NSURLRequest *)request returningResponse:(NSURLResponse * _Nullable * _Nullable)response error:(NSError **)error API_DEPRECATED("Use [NSURLSession dataTaskWithRequest:completionHandler:] (see NSURLSession.h", macos(10.3,10.11), ios(2.0,9.0), tvos(9.0,9.0)) API_UNAVAILABLE(watchos);

// 异步请求
+ (void)sendAsynchronousRequest:(NSURLRequest*) request
                          queue:(NSOperationQueue*) queue
              completionHandler:(void (^)(NSURLResponse* _Nullable response, NSData* _Nullable data, NSError* _Nullable connectionError)) handler API_DEPRECATED("Use [NSURLSession dataTaskWithRequest:completionHandler:] (see NSURLSession.h", macos(10.7,10.11), ios(5.0,9.0), tvos(9.0,9.0)) API_UNAVAILABLE(watchos);

小结：

1. 基本请求对象： NSURLRequest (NSURL)
2. 请求的对象(NSURLConnection)
3. 数据返回的回调 ； NSURLConnectionDelegate连接基本的回调 NSURLConnectionDataDelegate 数据 NSURLConnectionDownloadDelegate下载
4. 异步(队列) 、同步请求
5. 请求、取消请求