(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didSendBodyData:(int64_t)bytesSent totalBytesSent:(int64_t)totalBytesSent totalBytesExpectedToSend:(int64_t)totalBytesExpectedToSend { self.progress.completedUnitCount = totalBytesSent; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^これはios 9.0にかかっています。これどうする？？？
(void)URLSession:(NSURLSession *)セッション タスク:(NSURLSessionTask *)タスク didSendBodyData:(int64_t)bytesSent totalBytesSent:(int64_t)totalBytesSent totalBytesExpectedToSend:(int64_t)totalBytesExpectedToSend; メインスレッドで呼び出されることは重要ではありません
(lldb) bt * thread #1: tid = 0xd6e1, 0x00000001984a0c6c libsystem_kernel.dylib semaphore_wait_trap + 8, queue = 'com.apple.main-thread', activity = 'send control actions', 1 messages, stop reason = signal SIGSTOP
* frame #0: 0x00000001984a0c6c libsystem_kernel.dylibsemaphore_wait_trap + 8 frame #1: 0x000000019857a97c libsystem_platform.dylib _os_semaphore_wait + 24
frame #2: 0x00000001007bd428 libdispatch.dylib_dispatch_barrier_sync_f_slow + 600 frame #3: 0x00000001835af270 Foundation -[NSConcreteObservationBuffer _receiveBox:] + 248
frame #4: 0x00000001836180b0 Foundation_NSKVO1AdaptorDeliver + 388 frame #5: 0x0000000183617ea0 Foundation _NSKVO1AdaptorSlowDeliver + 264
frame #6: 0x0000000183523b84 Foundation-[NSKeyValueObservance observeValueForKeyPath :ofObject:change:context:] + 424 フレーム #7: 0x00000001834ffdd4 Foundation NSKeyValueNotifyObserver + 304
frame #8: 0x00000001834ff8fc FoundationNSKeyValueDidChange + 404 フレーム #9: 0x00000001834ea114 Foundation -[NSObject(NSKeyValueObserverNotification) didChangeValueForKey:] + 120
frame #10: 0x000000018258fab0 CoreFoundation__53-[__NSArrayM enumerateObjectsWithOptions:usingBlock:]_block_invoke + 132 フレーム #11: 0x00000001825-[__NSArrayM enumerateObjectsWithOptions:usingBlock:] + 308
frame #12: 0x00000001836cc158 Foundation-[NSProgress _setValueForKeys:settingBlock:] + 600 フレーム #13: 0x00000001836cc87c Foundation`-[NSProgress setCompletedUnitCount:] + 124
PS: UIProgressView::observedProgress をその NSProgress に設定しないと、正常に動作します!?