objective-c-blocks

问题 I've been trying to get a value from inside a block for a few hours now, I can't understand how to use the handlers on completion and literally everything. Here's my code: + (void)downloadUserID:(void(^)(NSString *result))handler { //Now redirect to assignments page __block NSMutableString *returnString = [[NSMutableString alloc] init]; //'__block' so that it has a direct connection to both scopes, in the method AND in the block NSURL *homeURL = [NSURL URLWithString:@"https://mistar.oakland

问题 I am using block based enumeration similar to the following code: [[[rows objectForKey:self.company.coaTypeCode] objectForKey:statementType] enumerateObjectsWithOptions:NSEnumerationConcurrent usingBlock:^(id coaItem, NSUInteger idx, BOOL *stop) { // block code here }] I would like to remove some of the objects during the enumeration process depending on the their object values. How could I do this? I know that manipulating an mutable array or dictionary (NSMutableArray or NSMutableDictionary

问题 Is there any way to make the rearView appear on top of the frontView as below image in storyboard using Objective-C. I want to make the Front View navigation Fixed & make sidebar button static. 回答1: This kind of android drawer external and open source library called as a CCKFNavDrawer . CCKFNavDrawer For using this following code. self.rootNav = (CCKFNavDrawer *)self.navigationController; [self.rootNav setCCKFNavDrawerDelegate:self]; Then implement delegate method - (void

问题 I'm having a hard time finding good examples on how to use these functions. static void * kQueue1Key = "key1"; static void * kQueue2Key = "key2"; dispatch_queue_t queue1 = dispatch_queue_create("com.company.queue1", DISPATCH_QUEUE_SERIAL); dispatch_queue_t queue2 = dispatch_queue_create("com.company.queue2", DISPATCH_QUEUE_SERIAL); dispatch_queue_set_specific(queue1, kQueue1Key, (void *)kQueue1Key, NULL); dispatch_queue_set_specific(queue2, kQueue2Key, (void *)kQueue2Key, NULL); dispatch_sync

问题 I'm having a hard time finding good examples on how to use these functions. static void * kQueue1Key = "key1"; static void * kQueue2Key = "key2"; dispatch_queue_t queue1 = dispatch_queue_create("com.company.queue1", DISPATCH_QUEUE_SERIAL); dispatch_queue_t queue2 = dispatch_queue_create("com.company.queue2", DISPATCH_QUEUE_SERIAL); dispatch_queue_set_specific(queue1, kQueue1Key, (void *)kQueue1Key, NULL); dispatch_queue_set_specific(queue2, kQueue2Key, (void *)kQueue2Key, NULL); dispatch_sync

问题 I want to use blocks in my application, but I don't really know anything about blocks. Can anyone explain how and why I should use blocks in my code? 回答1: Blocks are closures (or lambda functions, however you like to call them). Their purpose is that using blocks, the programmer doesn't have to create named functions in the global scope or provide a target-action callback, instead he/she can create an unnamed, local "function" which can access the variables in its enclosing scope and easily

问题 This question already has answers here : Caret character between types rather than variables, surrounded by parentheses (2 answers) Closed 5 years ago . In iPhone SDK 4.0, UIApplication has a new method, setKeepAliveTimeout: that requires a second parameter of type void(^)(void) . -(BOOL)setKeepAliveTimeout:(NSTimeInterval)timeout handler:(void(^)(void))keepAliveHandler What exactly does the syntax of the second parameter mean, and how would I declare a function/handler that I can pass into

问题 This question already has answers here : How do I return a variable from a block inside a method? (3 answers) Returning a variable value outside a block - Objective-C, iOS (1 answer) returning UIImage from block (3 answers) Closed 5 years ago . Thanks guy for help you. My problem is next. I need use AFNetworking and when request petition to server, the server is response. This result I need return in my method. The method AFNetworking use block for succes or failed. I want return the return

问题 This question already has answers here : Custom completion block for my own method [duplicate] (3 answers) Closed 4 years ago . Is it possible to run a block when a delegate receives a message? For example, if I had a framework that took a void block as a parameter (we'll call it the "success" block), and was using an NSURLConnection delegate to do stuff with those method arguments, when I receive a response from the webpage, how can I call the "success" block passed in the method parameters?

问题 This question already has answers here : Custom completion block for my own method [duplicate] (3 answers) Closed 4 years ago . Is it possible to run a block when a delegate receives a message? For example, if I had a framework that took a void block as a parameter (we'll call it the "success" block), and was using an NSURLConnection delegate to do stuff with those method arguments, when I receive a response from the webpage, how can I call the "success" block passed in the method parameters?