iOS NSDictionary、NSData、JSON数据类型相互转换

iOS NSDictionary、NSData、JSON数据类型相互转换

iOS经常需要用到数据类型的转换，下面列举一下常用类型的转换。

1.NSDictionary类型转换为NSData类型：

 

//NSDictionary -> NSData:

NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:

@"balance", @"key",

@"remaining balance", @"label",

@"45", @"value",

@"USD", @"currencyCode",nil];

NSMutableData *data = [[NSMutableData alloc] init];

NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];

[archiver encodeObject:params forKey:@"Some Key Value"];

[archiver finishEncoding];

 

2.NSData类型转换为NSDictionary类型：

 

//NSData -> 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];

 

3.NSDictionary类型转换为JSON数据类型：

 

//NSDictionary -> JSON:

NSString *jsonStr=[dict JSONRepresentation];

 
JSON与NSDictionary类型的转换一般会用到第三方公开的JSON库，可以在网上找到很多。