Ios NSMetadataQueryIDUpdateNotification不工作
有人能告诉我我从iOS5开发者食谱中改编的以下代码有什么问题吗Ios NSMetadataQueryIDUpdateNotification不工作,ios,icloud,Ios,Icloud,有人能告诉我我从iOS5开发者食谱中改编的以下代码有什么问题吗 - (void) startMonitoringUbiquitousDocumentsFolder { // Remove any existing query – stored in local instance variable if (alertQuery) [alertQuery stopQuery]; // Search for all file names alertQuery.pred
- (void) startMonitoringUbiquitousDocumentsFolder
{
// Remove any existing query – stored in local instance variable
if (alertQuery) [alertQuery stopQuery];
// Search for all file names
alertQuery.predicate = [NSPredicate predicateWithFormat: @"NSMetadataItemFSNameKey == '*'"];
alertQuery.searchScopes = [NSArray arrayWithObject:
NSMetadataQueryUbiquitousDocumentsScope];
// Subscribe to query updates
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(alertUserToUpdates:)
name:NSMetadataQueryDidUpdateNotification
object:nil];
[alertQuery startQuery];
}
- (void) alertUserToUpdates
{
NSLog(@"Contents changed in ubiquitous documents folder");
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:@"Home Monitor"
message:@"Something's going on."
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:@"Check Recording", nil];
[alertView show];
[self stopMonitoringUbiquitousDocumentsFolder];
}
我得到一个异常,它表示选择器AlertUserToUpdate:无法识别。为什么它不能识别出它旁边明显正确的方法
2013-04-29 18:07:22.458 eyeFun[8231:907] -[RGPViewController alertUserToUpdates:]: unrecognized selector sent to instance 0x1fd506a0
2013-04-29 18:07:22.462 eyeFun[8231:907] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[RGPViewController alertUserToUpdates:]: unrecognized selector sent to instance 0x1fd506a0'
*** First throw call stack:
(0x337eb3e7 0x3b4e6963 0x337eef31 0x337ed64d 0x33745208 0x3373c349 0x34053b7f 0x340ab327 0x3373c349 0x337b810f 0x37880de9 0x340fa657 0x337c0857 0x337c0503 0x337bf177 0x3373223d 0x337320c9 0x3731133b 0x3564e2b9 0x465b5 0x3b913b20)
libc++abi.dylib: terminate called throwing an exception
因为它不在它旁边 您告诉它使用名为
AlertUserToUpdate:
的选择器。您有一个名为AlertUserToUpdate
的方法。:
很重要——它说方法只接受一个参数,但实际的方法不接受参数
您的方法应该采用类型为
NSNotification
的参数。也可以使用@selector(AlertUserToUpdate)
更新选择器以指向您的方法-通知中心不介意调用不采用NSNotification
参数的方法。但大多数情况下,接受参数是一个更好的主意。多亏了这两种回答。我感谢你的帮助。