nsmutabledictionary

问题 I have a question on thread safety while using NSMutableDictionary . The main thread is reading data from NSMutableDictionary where: key is NSString value is UIImage An asynchronous thread is writing data to above dictionary (using NSOperationQueue ) How do I make the above dictionary thread safe? Should I make the NSMutableDictionary property atomic ? Or do I need to make any additional changes? @property(retain) NSMutableDictionary *dicNamesWithPhotos; 回答1: NSMutableDictionary isn't

问题 Question: Is there a way to use existing objective-c methods to do a full deep copy of a NSDictionary or NSArray, that themselves have nested dictionaries or arrays within them? That is I have read the problem may be when it hits a nested dictionary or array it only copies the pointer to the nested item, and not copy the item truely. Background: So as an example for me I\'m trying to load/save the following config with NSUserDefaults and when loading need to convert the immutable copies one

问题 I am developing an application in which I want to use an NSDictionary . Can anyone please send me a sample code explaining the procedure how to use an NSDictionary to store Data with a perfect example? 回答1: The NSDictionary and NSMutableDictionary docs are probably your best bet. They even have some great examples on how to do various things, like... ...create an NSDictionary NSArray *keys = [NSArray arrayWithObjects:@"key1", @"key2", nil]; NSArray *objects = [NSArray arrayWithObjects:@

问题 I have an NSMutableDictionary that maps NSString to NSString (although the values are NSStrings , they are really just integers). For example consider the following mappings, \"dog\" --> \"4\" \"cat\" --> \"3\" \"turtle\" --> \"6\" I\'d like to end up with the top 10 entries in the dictionary sorted by decreasing order of the value. Can someone show me code for this? Perhaps there is an array of keys and another array of values. However it is, I don\'t mind. I\'m just trying to have it be

问题 When looking at the documentation, I hardly see any big difference. Both \"value\" and \"object\" are of type id , so can be any object. Key is once a string, and in the other case an id. One of them seems to retain the object, and the other don\'t. What else? Which one is for what case? 回答1: setValue:forKey: is part of the NSKeyValueCoding protocol, which among other things, lets you access object properties from the likes of Interface Builder. setValue:forKey: is implemented in classes