如何將NSDictionary轉換爲NSData，反之亦然？

Question

我使用藍牙發送NSString和UIImage。我決定存儲在NSDictionary，然後將字典轉換爲NSData。

我的問題是如何將NSDictionary轉換爲NSData，反之亦然？

Answer 1

的NSDictionary - > NSData的：

NSData *myData = [NSKeyedArchiver archivedDataWithRootObject:myDictionary]; 

的NSData - >的NSDictionary：

NSDictionary *myDictionary = (NSDictionary*) [NSKeyedUnarchiver unarchiveObjectWithData:myData]; 

Answer 2

的NSDictionary從NSData的

http://www.cocoanetics.com/2009/09/nsdictionary-from-nsdata/

的NSDictionary到NSData的

可以使用NSPropertyListSerialization類爲。看看它的方法：

+ (NSData *)dataFromPropertyList:(id)plist format:(NSPropertyListFormat)format 
           errorDescription:(NSString **)errorString 

返回一個包含指定格式的給定屬性列表的NSData對象。

Answer 3

的NSDictionary - > NSData的：

NSMutableData *data = [[NSMutableData alloc] init]; 
NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data]; 
[archiver encodeObject:yourDictionary forKey:@"Some Key Value"]; 
[archiver finishEncoding]; 
[archiver release]; 

// Here, data holds the serialized version of your dictionary 
// do what you need to do with it before you: 
[data release]; 

的NSData - >的NSDictionary

NSData *data = [[NSMutableData alloc] initWithContentsOfFile:[self dataFilePath]]; 
NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data]; 
NSDictionary *myDictionary = [[unarchiver decodeObjectForKey:@"Some Key Value"] retain]; 
[unarchiver finishDecoding]; 
[unarchiver release]; 
[data release]; 

你可以做到這一點符合NSCoding任何類。

source

Answer 4

使用NSJSONSerialization：

NSDictionary *dict; 
NSData *dataFromDict = [NSJSONSerialization dataWithJSONObject:dict 
                 options:NSJSONWritingPrettyPrinted 
                 error:&error]; 

NSDictionary *dictFromData = [NSJSONSerialization JSONObjectWithData:dataFromDict 
                  options:NSJSONReadingAllowFragments 
                   error:&error]; 

最新收益id，所以它是一個好主意，檢查返回的對象類型你施放後（這裏我現澆到的NSDictionary）。

Answer 5

在斯威夫特2，你可以這樣做：

var dictionary: NSDictionary = ... 

/* NSDictionary to NSData */ 
let data = NSKeyedArchiver.archivedDataWithRootObject(dictionary) 

/* NSData to NSDictionary */ 
let unarchivedDictionary = NSKeyedUnarchiver.unarchiveObjectWithData(data!) as! NSDictionary 

在斯威夫特3：

/* NSDictionary to NSData */ 
let data = NSKeyedArchiver.archivedData(withRootObject: dictionary) 

/* NSData to NSDictionary */ 
let unarchivedDictionary = NSKeyedUnarchiver.unarchiveObject(with: data) 

Answer 6

請試試這個

NSError *error; 
NSDictionary *responseJson = [NSJSONSerialization JSONObjectWithData:webData 
           options:NSJSONReadingMutableContainers 
           error:&error];