阅读plist存储在内存NSDictionary
根据此post我可以使用加密/解密方法来安全地存储/检索plist文件。阅读plist存储在内存NSDictionary
但问题是:
问:我已经解密的plist文件后,我怎么能解析和存储plist文件作为NSDictrionary对象
你可以在这里使用核心基础的方式与方法CFPropertyListCreateFromXMLData
如果plist中代表的NSDictionary的内容,下面的检查应传递:
if ([(id)plist isKindOfClass:[NSDictionary class]])
和plist对象可能会被安全地转换为NSDictionary。如果否,数据或解锁过程出现问题。
最简单的方法将创造像这样的NSDictionary类别:
NSDictionaryWithData.h:
@interface NSDictionary (NSDictionaryWithData)
+ (id)dictionaryWithData:(NSData *)data;
- (id)initWithData:(NSData *)data;
@end
NSDictionaryWithData.m:
@implementation NSDictionary (NSDictionaryWithData)
+ (id)dictionaryWithData:(NSData *)data
{
return [[[NSDictionary alloc] initWithData:data] autorelease];
}
- (id)initWithData:(NSData *)data
{
self = (NSDictionary *)[NSPropertyListSerialization propertyListFromData:data
mutabilityOption:NSPropertyListImmutable
format:NULL
errorDescription:nil];
return [self retain];
}
@end
使用方法:
NSDictionary* myDict = [[NSDictionary alloc] initWithData:decryptedData];
dictionaryWithData不存在的一个可能原因是属性列表不一定是根级别的字典。它也可以是一个NSArray。
这里是我对一个解决方案:利用NSPropertyListSerialization
特点
- 默默丢弃包含阵列在根级别的数据的类别。
检查使用哪种方法(propertyListFromData:mutabilityOption:格式:ERRORDESCRIPTION:折旧)
的NSMutableDictionary也支持
注 - 这需要包装一类工厂方法用的非常规方法一个init方法。这是为了提高效率 - 大多数情况下,您将使用factory方法,它只是包装NSPropertyListSerialization,它在内部调用alloc/init/autorelease返回适当的对象。
NSDictionary + DictionaryWithData。ħ
#import <Foundation/Foundation.h>
@interface NSDictionary (DictionaryWithData)
+ (id)dictionaryWithData:(NSData *)data;
- (id)initWithData:(NSData *)data;
@end
的NSDictionary + DictionaryWithData.m
#import "NSDictionary+DictionaryWithData.h"
@implementation NSDictionary (DictionaryWithData)
+(NSPropertyListMutabilityOptions) mutabilityOption {
return NSPropertyListImmutable;
}
+ (id)dictionaryWithData:(NSData *)data
{
static BOOL methodChecked = NO;
static BOOL use_propertyListWithData = NO;
if (!methodChecked) {
SEL sel = @selector(propertyListWithData:options:format:error:);
use_propertyListWithData = [[NSPropertyListSerialization class]
respondsToSelector:sel];
methodChecked = YES;
}
id result;
if (use_propertyListWithData) {
result = [NSPropertyListSerialization propertyListWithData:data
options:[self mutabilityOption]
format:nil
error:nil];
} else {
result = [NSPropertyListSerialization propertyListFromData:data
mutabilityOption:[self mutabilityOption]
format:NULL
errorDescription:nil];
}
return [result isKindOfClass:[NSDictionary class]] ? result : nil;
}
- (id)initWithData:(NSData *)data
{
id result = [[self class] dictionaryWithData:data];
self = result ? [self initWithDictionary:result ] : nil;
return self;
}
@end
@implementation NSMutableDictionary (DictionaryWithData)
+(NSPropertyListMutabilityOptions) mutabilityOption {
return NSPropertyListMutableContainersAndLeaves;
}
@end
文档:https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSPropertyListSerialization_Class /Reference/Reference.html – calimarkus 2012-03-07 16:43:38