のセットを使用して複数のファイルをダウンロードしていますNSURLSessionDownloadTasks。
UITextView進行状況を次のように表示するがあります。
-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite
{
double progress = (double)totalBytesWritten / (double)totalBytesExpectedToWrite;
dispatch_async(dispatch_get_main_queue(), ^{
progressTextView.text = [NSString stringWithFormat:@"progress for task %lu: %.2f\n%@", (unsigned long)downloadTask.taskIdentifier, progress, progressTextView.text];
});
}
アプリがフォアグラウンドにあるときはすべて正常に動作しますが、バックグラウンドに送信すると、ダウンロードが終了したときに次のエラーが発生します。
*** Assertion failure in void _UIPerformResizeOfTextViewForTextContainer(NSLayoutManager *, UIView<NSTextContainerView> *, NSTextContainer *, NSUInteger)(), /SourceCache/UIFoundation_Sim/UIFoundation-258.1/UIFoundation/TextSystem/NSLayoutManager_Private.m:1510
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Only run on the main thread!'
*** First throw call stack:
(
0 CoreFoundation 0x017425e4 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x014c58b6 objc_exception_throw + 44
2 CoreFoundation 0x01742448 +[NSException raise:format:arguments:] + 136
3 Foundation 0x01172720 -[NSAssertionHandler handleFailureInFunction:file:lineNumber:description:] + 101
4 UIFoundation 0x02d47f81 -[NSLayoutManager(NSPrivate) _resizeTextViewForTextContainer:] + 419
5 UIFoundation 0x02d47c66 -[NSLayoutManager(NSPrivate) _recalculateUsageForTextContainerAtIndex:] + 2083
6 UIFoundation 0x02d47ce3 -[NSLayoutManager(NSPrivate) _validatedStoredUsageForTextContainerAtIndex:] + 96
7 UIFoundation 0x02d81e28 -[NSLayoutManager usedRectForTextContainer:] + 130
8 UIKit 0x0090a08d -[_UITextContainerView textContainerOrigin] + 97
9 UIKit 0x0090a9b3 -[_UITextContainerView drawRect:] + 146
10 UIKit 0x0029dd56 -[UIView(CALayerDelegate) drawLayer:inContext:] + 504
11 QuartzCore 0x03b4fdc9 -[CALayer drawInContext:] + 123
12 UIFoundation 0x02d7837d -[_UITextTiledLayer drawDirtyLayer:intoContext:] + 171
13 UIFoundation 0x02d78220 -[_UITileLayer drawInContext:] + 64
14 QuartzCore 0x03b4fcfa _ZL16backing_callbackP9CGContextPv + 96
15 QuartzCore 0x03a40cf4 CABackingStoreUpdate_ + 2656
16 QuartzCore 0x03b4fc92 ___ZN2CA5Layer8display_Ev_block_invoke + 93
17 QuartzCore 0x03b83b23 x_blame_allocations + 15
18 QuartzCore 0x03b4fafd _ZN2CA5Layer8display_Ev + 1519
19 QuartzCore 0x03b4fd49 -[CALayer _display] + 33
20 QuartzCore 0x03b4f506 _ZN2CA5Layer7displayEv + 144
21 QuartzCore 0x03b4fd23 -[CALayer display] + 33
22 QuartzCore 0x03b43ed3 _ZN2CA5Layer17display_if_neededEPNS_11TransactionE + 323
23 QuartzCore 0x03b43f4c _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 38
24 QuartzCore 0x03aabae6 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 294
25 QuartzCore 0x03aace71 _ZN2CA11Transaction6commitEv + 393
26 QuartzCore 0x03b69430 +[CATransaction flush] + 52
27 UIKit 0x0026f296 _UIWindowUpdateVisibleContextOrder + 232
28 UIKit 0x0026f145 +[UIWindow _prepareWindowsPassingTestForAppResume:] + 28
29 UIKit 0x00244016 -[UIApplication _updateSnapshotAndStateRestorationArchiveForBackgroundEvent:saveState:exitIfCouldNotRestoreState:] + 187
30 UIKit 0x0024481e __64-[UIApplication _handleBackgroundURLSessionEventWithIdentifier:]_block_invoke + 107
31 UIKit 0x00687877 ___UIAutologgingVoidBlock_block_invoke + 54
32 MyApp 0x000041d0 -[ViewController URLSessionDidFinishEventsForBackgroundURLSession:] + 288
33 CFNetwork 0x062660f0 __67-[__NSCFURLSession delegate_didFinishEventsForBackgroundURLSession]_block_invoke + 49
34 CFNetwork 0x06264286 __37-[__NSCFURLSession addDelegateBlock:]_block_invoke + 133
35 Foundation 0x01141945 -[NSBlockOperation main] + 88
36 Foundation 0x0119a829 -[__NSOperationInternal _start:] + 671
37 Foundation 0x01117558 -[NSOperation start] + 83
38 Foundation 0x0119caf4 __NSOQSchedule_f + 62
39 libdispatch.dylib 0x01aee4b0 _dispatch_client_callout + 14
40 libdispatch.dylib 0x01adc07f _dispatch_queue_drain + 452
41 libdispatch.dylib 0x01adbe7a _dispatch_queue_invoke + 128
42 libdispatch.dylib 0x01adce1f _dispatch_root_queue_drain + 83
43 libdispatch.dylib 0x01add137 _dispatch_worker_thread2 + 39
44 libsystem_pthread.dylib 0x01e7adab _pthread_wqthread + 336
45 libsystem_pthread.dylib 0x01e7ecce start_wqthread + 30
)
libc++abi.dylib: terminating with uncaught exception of type NSException
この回答が示唆しているように、これがメインスレッドで実行されるようにしています。
正確に何がうまくいかないのですか？