nsarray

问题 I have an array which is filled with NSDictionaries . I want to find the index of one of the dictionary, but what I know about this dictionary is only a value for key @"name". How do I do it ? 回答1: Find index of first dictionary in theArray whose value for @"name" is theValue : NSUInteger index = [theArray indexOfObjectPassingTest: ^BOOL(NSDictionary *dict, NSUInteger idx, BOOL *stop) { return [[dict objectForKey:@"name"] isEqual:theValue]; } ]; index will be NSNotFound if no matching object

问题 ABAddressBookRef addressBook = ABAddressBookCreate(); CFArrayRef allPeople = ABAddressBookCopyArrayOfAllPeople(addressBook); CFIndex nPeople = ABAddressBookGetPersonCount(addressBook); NSMutableArray *tempPeoples=[[NSMutableArray alloc]init]; for(int i=0;i<nPeople;i++){ ABRecordRef i1=CFArrayGetValueAtIndex(allPeople, i); [tempPeoples addObject:i1]; // [peoples addObject:i1]; }// end of the for loop peoples=[tempPeoples copy]; This code gives exception b/c I want to convert NSMutableArray to

问题 I've already seen two similar questions to mine, but the answers for those questions do not work for me. I have an old project with a list of countries manually typed out inside a set of square brackets. I can easily use this in my pickerView but I'm wondering if there is a more efficient way to do this? I will be using the list of countries in a UIPickerView. 回答1: You can get a list of countries using the NSLocale class's isoCountryCodes which returns an array of [String] . From there, you

问题 I want to add @"ALL ITEMS" object at the first index of NSARRAY. Initially the Array has 10 objects. After adding, the array should contains 11 objects. 回答1: First of all, NSArray need to be populated when it is initializing. So if you want to add some object at an array then you have to use NSMutableArray. Hope the following code will give you some idea and solution. NSArray *array = [[NSArray alloc] initWithObjects:@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"0", nil]; NSMutableArray

问题 I have an NSArray of UILocalNotification objects that I need to sort according to a key within the UILocalNotification's userInfo property, which is an NSDictionary. I know how to sort NSArrays by a value that is one level deep, e.g., a key within an array of NSDictionaries, but two levels deep I'm lost. I want to do something like this is psuedo-code: NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"userInfo.personName" ascending:YES]; //the personName key within

问题 I have an app that allows users to save and open text files. Saving and opening files is fairly straightforward and easy, but I have to give the user an easy way to select a file to open. I decided to do this with a UITableView . When the TableView loads in my view controller, my goal is to populate the TableView with the names of all of the user's text files from within the Documents folder (part of the iOS App Sandbox). I have a general idea of how to do this: Get the contents of the

问题 can anyone clear this up for me ? I am building an iPad App that has a TableViewController that is supposed to show something between 1000 and 2000 strings. I have those NSStrings in a Singleton. In the init Method of the Singleton I initialize an Array that holds all the data ( does not have to be the final way to do it - was just a quick copy and paste for testing ) I did an self.someArray = [[NSArray alloc]initWithObjects: followed by the large number of strings, followed by nil. that

问题 can anyone clear this up for me ? I am building an iPad App that has a TableViewController that is supposed to show something between 1000 and 2000 strings. I have those NSStrings in a Singleton. In the init Method of the Singleton I initialize an Array that holds all the data ( does not have to be the final way to do it - was just a quick copy and paste for testing ) I did an self.someArray = [[NSArray alloc]initWithObjects: followed by the large number of strings, followed by nil. that

问题 I create an array based on a dictionaries key's: factsBuiltArray = [NSMutableArray arrayWithCapacity: 6]; if ([statusDict count] == 10) { for (NSString *key in [statusDict allKeys]) { if ([key isEqualToString: @"currenciesAndConversions"]) { [factsBuiltArray insertObject:key atIndex: 0]; } else if ([key isEqualToString: @"languageAndTranslations"]) { [factsBuiltArray insertObject:key atIndex: 1]; } else if ([key isEqualToString: @"plugSize"]) { [factsBuiltArray insertObject:key atIndex: 2]; }

问题 I have been struggling to find an easy way to sort an NSMutableArray that contains NSDictionaries. Each NSDictionary has a key named "Date" which contains an NSString of a date (ex: 10/15/2014). What I am looking to do is sort the array based on those strings in ascending order. I have tried this with no luck: NSComparisonResult dateSort(NSString *s1, NSString *s2, void *context) { NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; [formatter setDateFormat:@"MM/dd/yy"]; NSDate *d1 =