崩溃信息打印：
2014-01-17 17:36:47.932 BuyBuyring[32900:9413] bool _WebTryThreadLock(bool), 0xf0d4e50: Tried to obtain the web lock from a thread other than the main thread or the web thread. This may be a result of calling to UIKit from a secondary thread. Crashing now...
1 _ZL17_WebTryThreadLockb
2 WebThreadLock
3 -[UITextRangeImpl isEmpty]
4 -[UITextRange(UITextSelectionAdditions) _isCaret]
5 -[UITextSelectionView setCaretBlinks:]
6 -[UIKeyboardImpl setCaretBlinks:]
7 -[UIKeyboardImpl setDelegate:force:]
8 -[UIPeripheralHost(UIKitInternal) _reloadInputViewsForResponder:]
9 -[UINavigationController navigationTransitionView:didStartTransition:]
10 -[UINavigationTransitionView transition:fromView:toView:]
11 -[UINavigationTransitionView transition:toView:]
12 -[UINavigationController _startTransition:fromViewController:toViewController:]
13 -[UINavigationController _startDeferredTransitionIfNeeded]
14 -[UINavigationController pushViewController:transition:forceImmediate:]
15 -[UINavigationController pushViewController:animated:]
2014-01-17 17:36:48.114 BuyBuyring[32900:707] (
{
merchant = (
);
product = "<ProductItem: 0xf028d30>";
}
)
16 -[RootViewController searchDelegateMetod:]
17 -[NSThread main]
18 __NSThread__main__
19 _pthread_start
20 thread_start
(lldb)
刚开始不知道这是什么原因，百度了一下，说是在线程中更新了UI界面，崩溃在这里（下图）：
然后在调用searchdelegate的方法那里发现自己写错了（粗心啊），本来想要写下面的第一段代码，竟写成了第二段代码：
[self.delegate performSelector:@selector(searchDelegateMetod:) withObject:[dataarray objectAtIndex:indexPath.row]];
[self.delegate performSelectorInBackground:@selector(searchDelegateMetod:) withObject:[dataarray objectAtIndex:indexPath.row]];
所以就出现上面的错误了，呵呵
bool _WebTryThreadLock(bool), 0xf0d4e50:
原文：http://blog.csdn.net/demoker/article/details/18412993