There is an exception being thrown when a user scrolls through my UITableView too fast or taps the status bar to jump to the top of the table. I am only seeing this crash on an iPhone 5C device. I can't reproduce it on the 4S, 5, or with the 32-bit simulator.
Using the "All Exceptions" breakpoint, I was able to print out all the backtraces I could incrementing the frame pointer through the crash. Because there is no trace of my app in the backtrace (besides the main), I assume this is an Apple bug, something to do with [NSRLEArray objectAtIndex:effectiveRange:]. The author of this question seemed to have the same problem with an OS X application, and a comment suggested looking at the NSAttributedString usage in my app. I do use NSAttributedStrings in my table view cells to hyperlink certain strings in a UITextView. But if it was a general issue with NSAttributedString, wouldn't this also cause a crash on other iOS devices?
Backtrace:
(lldb) bt
* thread #1: tid = 0x2e57bd, 0x3978e6a0 libobjc.A.dylib`objc_exception_throw, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
frame #0: 0x3978e6a0 libobjc.A.dylib`objc_exception_throw
frame #1: 0x2f431dc4 CoreFoundation`+[NSException raise:format:] + 112
frame #2: 0x2fd55230 Foundation`-[NSRLEArray objectAtIndex:effectiveRange:] + 120
frame #3: 0x2fd71d76 Foundation`-[NSConcreteMutableAttributedString addAttribute:value:range:] + 198
frame #4: 0x36d7b278 UIFoundation`__50-[NSConcreteTextStorage addAttribute:value:range:]_block_invoke + 156
frame #5: 0x36d7b102 UIFoundation`-[NSConcreteTextStorage addAttribute:value:range:] + 170
frame #6: 0x337fc02e DataDetectorsUI`-[DDTextKitOperation _addResultsToAttributes] + 266
frame #7: 0x337fc1d6 DataDetectorsUI`__46-[DDTextKitOperation doURLificationOnDocument]_block_invoke_2 + 26
frame #8: 0x36d79a5e UIFoundation`-[NSTextStorage(ActorSupport) coordinateAccess:] + 34
frame #9: 0x337fc1b8 DataDetectorsUI`__46-[DDTextKitOperation doURLificationOnDocument]_block_invoke + 116
frame #10: 0x39c78bde libdispatch.dylib`_dispatch_barrier_sync_f_slow_invoke + 66
frame #11: 0x39c730ae libdispatch.dylib`_dispatch_client_callout + 22
frame #12: 0x39c759a8 libdispatch.dylib`_dispatch_main_queue_callback_4CF + 268
frame #13: 0x2f3fc5b0 CoreFoundation`__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 8
frame #14: 0x2f3fae7c CoreFoundation`__CFRunLoopRun + 1308
frame #15: 0x2f365470 CoreFoundation`CFRunLoopRunSpecific + 524
frame #16: 0x2f365252 CoreFoundation`CFRunLoopRunInMode + 106
frame #17: 0x3409f2ea GraphicsServices`GSEventRunModal + 138
frame #18: 0x31c1a844 UIKit`UIApplicationMain + 1136
* frame #19: 0x000bffb4 [AppName]`main(argc=1, argv=0x27d4ecec) + 116 at main.m:16
(lldb) bt
* thread #1: tid = 0x2e57bd, 0x39153994 libc++abi.dylib`__cxa_throw, queue = 'com.apple.main-thread', stop reason = breakpoint 1.2
frame #0: 0x39153994 libc++abi.dylib`__cxa_throw
frame #1: 0x3978e79a libobjc.A.dylib`objc_exception_throw + 250
frame #2: 0x2f431dc4 CoreFoundation`+[NSException raise:format:] + 112
frame #3: 0x2fd55230 Foundation`-[NSRLEArray objectAtIndex:effectiveRange:] + 120
frame #4: 0x2fd71d76 Foundation`-[NSConcreteMutableAttributedString addAttribute:value:range:] + 198
frame #5: 0x36d7b278 UIFoundation`__50-[NSConcreteTextStorage addAttribute:value:range:]_block_invoke + 156
frame #6: 0x36d7b102 UIFoundation`-[NSConcreteTextStorage addAttribute:value:range:] + 170
frame #7: 0x337fc02e DataDetectorsUI`-[DDTextKitOperation _addResultsToAttributes] + 266
frame #8: 0x337fc1d6 DataDetectorsUI`__46-[DDTextKitOperation doURLificationOnDocument]_block_invoke_2 + 26
frame #9: 0x36d79a5e UIFoundation`-[NSTextStorage(ActorSupport) coordinateAccess:] + 34
frame #10: 0x337fc1b8 DataDetectorsUI`__46-[DDTextKitOperation doURLificationOnDocument]_block_invoke + 116
frame #11: 0x39c78bde libdispatch.dylib`_dispatch_barrier_sync_f_slow_invoke + 66
frame #12: 0x39c730ae libdispatch.dylib`_dispatch_client_callout + 22
frame #13: 0x39c759a8 libdispatch.dylib`_dispatch_main_queue_callback_4CF + 268
frame #14: 0x2f3fc5b0 CoreFoundation`__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 8
frame #15: 0x2f3fae7c CoreFoundation`__CFRunLoopRun + 1308
frame #16: 0x2f365470 CoreFoundation`CFRunLoopRunSpecific + 524
frame #17: 0x2f365252 CoreFoundation`CFRunLoopRunInMode + 106
frame #18: 0x3409f2ea GraphicsServices`GSEventRunModal + 138
frame #19: 0x31c1a844 UIKit`UIApplicationMain + 1136
* frame #20: 0x000bffb4 [AppName]`main(argc=1, argv=0x27d4ecec) + 116 at main.m:16
(lldb) bt
* thread #1: tid = 0x2e57bd, 0x3978e6a0 libobjc.A.dylib`objc_exception_throw, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
frame #0: 0x3978e6a0 libobjc.A.dylib`objc_exception_throw
frame #1: 0x2f431b88 CoreFoundation`-[NSException raise] + 8
frame #2: 0x36d7b19a UIFoundation`-[NSConcreteTextStorage addAttribute:value:range:] + 322
frame #3: 0x337fc02e DataDetectorsUI`-[DDTextKitOperation _addResultsToAttributes] + 266
frame #4: 0x337fc1d6 DataDetectorsUI`__46-[DDTextKitOperation doURLificationOnDocument]_block_invoke_2 + 26
frame #5: 0x36d79a5e UIFoundation`-[NSTextStorage(ActorSupport) coordinateAccess:] + 34
frame #6: 0x337fc1b8 DataDetectorsUI`__46-[DDTextKitOperation doURLificationOnDocument]_block_invoke + 116
frame #7: 0x39c78bde libdispatch.dylib`_dispatch_barrier_sync_f_slow_invoke + 66
frame #8: 0x39c730ae libdispatch.dylib`_dispatch_client_callout + 22
frame #9: 0x39c759a8 libdispatch.dylib`_dispatch_main_queue_callback_4CF + 268
frame #10: 0x2f3fc5b0 CoreFoundation`__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 8
frame #11: 0x2f3fae7c CoreFoundation`__CFRunLoopRun + 1308
frame #12: 0x2f365470 CoreFoundation`CFRunLoopRunSpecific + 524
frame #13: 0x2f365252 CoreFoundation`CFRunLoopRunInMode + 106
frame #14: 0x3409f2ea GraphicsServices`GSEventRunModal + 138
frame #15: 0x31c1a844 UIKit`UIApplicationMain + 1136
* frame #16: 0x000bffb4 [AppName]`main(argc=1, argv=0x27d4ecec) + 116 at main.m:16
(lldb) bt
* thread #1: tid = 0x2e57bd, 0x39153994 libc++abi.dylib`__cxa_throw, queue = 'com.apple.main-thread', stop reason = breakpoint 1.2
frame #0: 0x39153994 libc++abi.dylib`__cxa_throw
frame #1: 0x3978e79a libobjc.A.dylib`objc_exception_throw + 250
frame #2: 0x2f431b88 CoreFoundation`-[NSException raise] + 8
frame #3: 0x36d7b19a UIFoundation`-[NSConcreteTextStorage addAttribute:value:range:] + 322
frame #4: 0x337fc02e DataDetectorsUI`-[DDTextKitOperation _addResultsToAttributes] + 266
frame #5: 0x337fc1d6 DataDetectorsUI`__46-[DDTextKitOperation doURLificationOnDocument]_block_invoke_2 + 26
frame #6: 0x36d79a5e UIFoundation`-[NSTextStorage(ActorSupport) coordinateAccess:] + 34
frame #7: 0x337fc1b8 DataDetectorsUI`__46-[DDTextKitOperation doURLificationOnDocument]_block_invoke + 116
frame #8: 0x39c78bde libdispatch.dylib`_dispatch_barrier_sync_f_slow_invoke + 66
frame #9: 0x39c730ae libdispatch.dylib`_dispatch_client_callout + 22
frame #10: 0x39c759a8 libdispatch.dylib`_dispatch_main_queue_callback_4CF + 268
frame #11: 0x2f3fc5b0 CoreFoundation`__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 8
frame #12: 0x2f3fae7c CoreFoundation`__CFRunLoopRun + 1308
frame #13: 0x2f365470 CoreFoundation`CFRunLoopRunSpecific + 524
frame #14: 0x2f365252 CoreFoundation`CFRunLoopRunInMode + 106
frame #15: 0x3409f2ea GraphicsServices`GSEventRunModal + 138
frame #16: 0x31c1a844 UIKit`UIApplicationMain + 1136
* frame #17: 0x000bffb4 [AppName]`main(argc=1, argv=0x27d4ecec) + 116 at main.m:16
(lldb) bt
* thread #1: tid = 0x2e57bd, 0x39d3e1fc libsystem_kernel.dylib`__pthread_kill + 8, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
frame #0: 0x39d3e1fc libsystem_kernel.dylib`__pthread_kill + 8
frame #1: 0x39da5a52 libsystem_pthread.dylib`pthread_kill + 58
frame #2: 0x39cef02c libsystem_c.dylib`abort + 76
frame #3: 0x001f32ba [AppName]`uncaught_exception_handler + 26
frame #4: 0x2f432184 CoreFoundation`__handleUncaughtException + 580
frame #5: 0x3978e926 libobjc.A.dylib`_objc_terminate() + 174
frame #6: 0x391541b2 libc++abi.dylib`std::__terminate(void (*)()) + 78
frame #7: 0x39153d16 libc++abi.dylib`__cxa_rethrow + 102
frame #8: 0x3978e80e libobjc.A.dylib`objc_exception_rethrow + 42
frame #9: 0x36d7b150 UIFoundation`-[NSConcreteTextStorage addAttribute:value:range:] + 248
frame #10: 0x337fc02e DataDetectorsUI`-[DDTextKitOperation _addResultsToAttributes] + 266
frame #11: 0x337fc1d6 DataDetectorsUI`__46-[DDTextKitOperation doURLificationOnDocument]_block_invoke_2 + 26
frame #12: 0x36d79a5e UIFoundation`-[NSTextStorage(ActorSupport) coordinateAccess:] + 34
frame #13: 0x337fc1b8 DataDetectorsUI`__46-[DDTextKitOperation doURLificationOnDocument]_block_invoke + 116
frame #14: 0x39c78bde libdispatch.dylib`_dispatch_barrier_sync_f_slow_invoke + 66
frame #15: 0x39c730ae libdispatch.dylib`_dispatch_client_callout + 22
frame #16: 0x39c759a8 libdispatch.dylib`_dispatch_main_queue_callback_4CF + 268
frame #17: 0x2f3fc5b0 CoreFoundation`__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 8
frame #18: 0x2f3fae7c CoreFoundation`__CFRunLoopRun + 1308
frame #19: 0x2f365470 CoreFoundation`CFRunLoopRunSpecific + 524
frame #20: 0x2f365252 CoreFoundation`CFRunLoopRunInMode + 106
frame #21: 0x3409f2ea GraphicsServices`GSEventRunModal + 138
frame #22: 0x31c1a844 UIKit`UIApplicationMain + 1136
* frame #23: 0x000bffb4 [AppName]`main(argc=1, argv=0x27d4ecec) + 116 at main.m:16
(lldb) bt
* thread #22: tid = 0x2e57ea, 0x39da2cbc libsystem_pthread.dylib`start_wqthread, stop reason = signal SIGABRT
* frame #0: 0x39da2cbc libsystem_pthread.dylib`start_wqthread
Here is where I set the attributed string:
// earlier in the code
tweetTextView.attributedText = [[NSAttributedString alloc] initWithString:tweetTextView.text];
...
-(void)findHashtagsAndAtMentionsInTweetText:(UITextView *)textView {
NSString *tweetText = textView.text;
NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(@(\\w+))|(^|\\W)(#|\\uFF03)(\\w*\\p{L}\\w*)" options:0 error:&error];
NSArray *matches = [regex matchesInString:tweetText options:0 range:NSMakeRange(0, tweetText.length)];
NSMutableAttributedString * myTagOrMention = [[NSMutableAttributedString alloc] initWithString:tweetTextView.text];
for (NSTextCheckingResult *match in matches) {
NSRange wordRange = [match rangeAtIndex:0]; // causing crash?
NSString* word = [tweetText substringWithRange:wordRange];
if([word rangeOfString:@"@"].location != NSNotFound) {
// @ mention
// remove whitespaces and @
NSString *formattedTag = [NSString stringWithFormat:@"%@", [[word stringByReplacingOccurrencesOfString:@" " withString:@""] stringByReplacingOccurrencesOfString:@"@" withString:@""]];
NSString *tweetContets = tweetTextView.text;
NSRange range = [tweetContets rangeOfString:word];
if([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:@"twitter://"]]) {
NSString *twitterAppURL = [NSString stringWithFormat:@"%@%@", @"twitter://user?screen_name=",formattedTag];
[myTagOrMention addAttribute:NSLinkAttributeName value:twitterAppURL range:range];
} else {
[myTagOrMention addAttribute:NSLinkAttributeName value:[NSString stringWithFormat:@"%@%@", @"http://mobile.twitter.com/",formattedTag] range:range];
}
tweetTextView.attributedText = myTagOrMention;
} else {
// hashtag
// remove whitespaces and pound
NSString *formattedTag = [NSString stringWithFormat:@"%@", [[word stringByReplacingOccurrencesOfString:@" " withString:@""] stringByReplacingOccurrencesOfString:@"#" withString:@""]];
NSString *tweetContets = tweetTextView.text;
NSRange range = [tweetContets rangeOfString:word];
[myTagOrMention addAttribute:NSLinkAttributeName value:[NSString stringWithFormat:@"%@%@%@%@", @"http://twitter.com/search/", @"?q=%23", formattedTag, @"&s=hash"] range:range];
tweetTextView.attributedText = myTagOrMention;
}
}
Aaron Brager
The bug is not in the code you posted. The bug happens when a UITextView is reused while its links are still being generated, which is done asynchronously.
See these similar Stack Overflow questions:
- iOS 7 UITextView link detection crash in UITableView
- UITextViews in a UITableView link detection bug in iOS 7
- UITextView link detection in iOS 7
Many users have reported that setting the text view's text property to nil in the cell's prepareForReuse method resolves the issue. Alternatively you could use a library like TTTAttributedLabel instead of a text view.
The fact that it only appears on an iPhone 5C is probably a red herring. I bet this device is still running iOS 7, and the other devices have been updated to a newer version of iOS.
On a side note, there may be edge cases that your regex doesn't cover. I would delete your twitter parsing method and replace it with the official twitter-text-objc library.
来源：https://stackoverflow.com/questions/25748671/scrolling-through-uitableview-causes-exception-and-crash-only-on-iphone-5c