原文链接
http://blog.sina.com.cn/s/blog_5971cdd00102vqgy.html
UDID被弃用,使用UUID来作为设备的唯一标识。获取到UUID后,如果用NSUserDefaults存储,当程序被卸载后重装时,再获得的UUID和之前就不同了。使用keychain存储可以保证程序卸载重装时,UUID不变。但当刷机或者升级系统后,UUID还是会改变的。但这仍是目前为止最佳的解决办法了,如果有更好的解决办法,欢迎留言。
(我整理的解决办法的参考来源:http://blog.k-res.net/archives/1081.html)
给大家两个类:
UUID.h中的代码:
#import
尖括号(Foundation/Foundation.h)
@interface UUID : NSObject
+(NSString *)getUUID;
@end
UUID.m中的代码:
#import "UUID.h"
#import 尖括号(Foundation/Foundation.h)
#import
"KeychainItemWrapper.h"
@implementation UUID
+(NSString *)getUUID
{
KeychainItemWrapper *keychainItem = [[KeychainItemWrapper
alloc]
initWithIdentifier:@"UUID"
accessGroup:@"YOUR_BUNDLE_SEED.com.yourcompany.userinfo"];
NSString *strUUID = [keychainItem
objectForKey:(id)CFBridgingRelease(kSecValueData)];
//首次执行该方法时,uuid为空
if ([strUUID isEqualToString:@""])
{
CFUUIDRef uuidRef = CFUUIDCreate(kCFAllocatorDefault);
strUUID = (NSString *)CFBridgingRelease(CFUUIDCreateString (kCFAllocatorDefault,uuidRef));
[keychainItem setObject:strUUID forKey:(id)CFBridgingRelease(kSecValueData)];
}
return strUUID;
}
@end
第二个类是苹果官方的一个Demo里封装的,Demo的下载地址:http://developer.apple.com/library/ios/#samplecode/GenericKeychain/Listings/Classes_KeychainItemWrapper_h.html#//apple_ref/doc/uid/DTS40007797-Classes_KeychainItemWrapper_h-DontLinkElementID_9
KeychainItemWrapper.h中的代码:
#import 尖括号(UIKit/UIKit.h)
@interface KeychainItemWrapper
: NSObject
{
NSMutableDictionary *keychainItemData;
NSMutableDictionary *genericPasswordQuery;
}
@property (nonatomic, retain) NSMutableDictionary *keychainItemData;
@property (nonatomic, retain) NSMutableDictionary
*genericPasswordQuery;
- (id)initWithIdentifier:
(NSString *)identifier
accessGroup:(NSString *)
accessGroup;
- (void)setObject:(id)inObject forKey:(id)key;
- (id)objectForKey:(id)key;
- (void)resetKeychainItem;
@end
KeychainItemWrapper.m中的代码:
#import
"KeychainItemWrapper.h"
#import
尖括号(Security/Security.h)
@interface KeychainItemWrapper
(PrivateMethods)
- (NSMutableDictionary
*)secItemFormatToDictionary:(NSDictionary *)dictionaryToConvert;
- (NSMutableDictionary
*)dictionaryToSecItemFormat:(NSDictionary *)dictionaryToConvert;
-
(void)writeToKeychain;
@end
@implementation
KeychainItemWrapper
@synthesize keychainItemData,
genericPasswordQuery;
- (id)initWithIdentifier:
(NSString *)identifier
accessGroup:(NSString *)
accessGroup;
{
if (self = [super init])
{
genericPasswordQuery = [[NSMutableDictionary alloc]
init];
[genericPasswordQuery setObject:(id)CFBridgingRelease(kSecClassGenericPassword) forKey:(id)kSecClass];
[genericPasswordQuery setObject:identifier forKey:(id)CFBridgingRelease(kSecAttrGeneric)];
if (accessGroup != nil)
{
#if TARGET_IPHONE_SIMULATOR
#else
[genericPasswordQuery setObject:accessGroup forKey:(id)kSecAttrAccessGroup];
#endif
}
[genericPasswordQuery setObject:(id)CFBridgingRelease(kSecMatchLimitOne) forKey:(id)kSecMatchLimit];
[genericPasswordQuery setObject:(id)kCFBooleanTrue forKey:(id)kSecReturnAttributes];
NSDictionary
*tempQuery = [NSDictionary
dictionaryWithDictionary:genericPasswordQuery];
NSMutableDictionary *outDictionary =
nil;
if (!
SecItemCopyMatching((CFDictionaryRef)tempQuery, (CFTypeRef *)&outDictionary) ==
noErr)
{
[self
resetKeychainItem];
[keychainItemData setObject:identifier forKey:(id)kSecAttrGeneric];
if (accessGroup != nil)
{
#if TARGET_IPHONE_SIMULATOR
#else
[keychainItemData setObject:accessGroup forKey:(id)kSecAttrAccessGroup];
#endif
}
}
else
{
self.keychainItemData = [self secItemFormatToDictionary:outDictionary];
}
[outDictionary release];
}
return self;
}
- (void)dealloc
{
[keychainItemData release];
[genericPasswordQuery release];
[super dealloc];
}
- (void)setObject:(id)inObject forKey:(id)key
{
if (inObject == nil) return;
id currentObject = [keychainItemData objectForKey:key];
if (![currentObject isEqual:inObject])
{
[keychainItemData setObject:inObject forKey:key];
[self writeToKeychain];
}
}
- (id)objectForKey:(id)key
{
return [keychainItemData objectForKey:key];
}
- (void)resetKeychainItem
{
OSStatus junk = noErr;
if
(!keychainItemData)
{
self.keychainItemData = [[NSMutableDictionary alloc] init];
}
else
if (keychainItemData)
{
NSMutableDictionary *tempDictionary =
[self dictionaryToSecItemFormat:keychainItemData];
junk = SecItemDelete((CFDictionaryRef)tempDictionary);
NSAssert( junk
== noErr || junk == errSecItemNotFound, @"Problem deleting current dictionary."
);
}
[keychainItemData
setObject:@"" forKey:(id)kSecAttrAccount];
[keychainItemData setObject:@""
forKey:(id)kSecAttrLabel];
[keychainItemData
setObject:@""
forKey:(id)kSecAttrDescription];
[keychainItemData
setObject:@""
forKey:(id)kSecValueData];
}
- (NSMutableDictionary
*)dictionaryToSecItemFormat:(NSDictionary *)dictionaryToConvert
{
NSMutableDictionary *returnDictionary =
[NSMutableDictionary dictionaryWithDictionary:dictionaryToConvert];
[returnDictionary setObject:(id)kSecClassGenericPassword forKey:(id)kSecClass];
NSString *passwordString =
[dictionaryToConvert objectForKey:(id)kSecValueData];
[returnDictionary setObject:[passwordString
dataUsingEncoding:NSUTF8StringEncoding] forKey:(id)kSecValueData];
return returnDictionary;
}
- (NSMutableDictionary
*)secItemFormatToDictionary:(NSDictionary *)dictionaryToConvert
{
NSMutableDictionary *returnDictionary =
[NSMutableDictionary
dictionaryWithDictionary:dictionaryToConvert];
[returnDictionary
setObject:(id)kCFBooleanTrue forKey:(id)kSecReturnData];
[returnDictionary setObject:(id)kSecClassGenericPassword forKey:(id)kSecClass];
NSData *passwordData =
NULL;
if (SecItemCopyMatching((CFDictionaryRef)returnDictionary,
(CFTypeRef *)&passwordData)
== noErr)
{
[returnDictionary
removeObjectForKey:(id)kSecReturnData];
NSString *password =
[[[NSString
alloc] initWithBytes:[passwordData
bytes] length:[passwordData
length]
encoding:NSUTF8StringEncoding] autorelease];
[returnDictionary setObject:password forKey:(id)kSecValueData];
}
else
{
NSAssert(NO,
@"Serious error, no matching item found in the
keychain.
");
}
[passwordData release];
return returnDictionary;
}
- (void)writeToKeychain
{
NSDictionary *attributes = NULL;
NSMutableDictionary *updateItem =
NULL;
OSStatus result;
if (SecItemCopyMatching((CFDictionaryRef)genericPasswordQuery, (CFTypeRef *)&attributes) ==
noErr)
{
updateItem
= [NSMutableDictionary dictionaryWithDictionary:attributes];
[updateItem setObject:[genericPasswordQuery objectForKey:(id)kSecClass] forKey:(id)kSecClass];
NSMutableDictionary *tempCheck =
[self dictionaryToSecItemFormat:keychainItemData];
[tempCheck removeObjectForKey:(id)kSecClass];
#if TARGET_IPHONE_SIMULATOR
[tempCheck removeObjectForKey:(id)kSecAttrAccessGroup];
#endif
result = SecItemUpdate((CFDictionaryRef)updateItem, (CFDictionaryRef)tempCheck);
NSAssert( result == noErr,
@"Couldn't update the Keychain Item." );
}
else
{
result
= SecItemAdd((CFDictionaryRef)[self
dictionaryToSecItemFormat:keychainItemData],
NULL);
NSAssert( result == noErr,
@"Couldn't add the Keychain Item." );
}
}
@end
PS:
1. KeychainItemWrapper类在官方Demo里面也有,如果我复制出错了,大家可以在上面的链接上下载官方Demo.
2.使用时要添加Security.framework
3. 尤为注意的是,UUID类下面这句代码中group的设置方法。
KeychainItemWrapper
*keychainItem =
[[KeychainItemWrapper
alloc]
initWithIdentifier:@"UUID"
accessGroup:@"YOUR_BUNDLE_SEED.com.yourcompany.userinfo"];
(1)在项目相同的目录下创建KeychainAccessGroups.plist文件。
该文件的结构中最顶层的节点必须是一个名为“keychain-access-groups”的Array,并且该Array中每一项都是一个描述分组的NSString。YOUR_BUNDLE_SEED.com.yourcompany.userinfo就是要设置的组名。
(2)在项目相同的目录下创建KeychainAccessGroups.plist文件。在Target-Build
Settings-Code Signing栏下的Code
Signing Entitlements右侧添加KeychainAccessGroups.plist,如下图。
到此,工作就完成了。
首次安装程序时,打印出一个uuid,当把程序卸载后,再用getUUID获得
uuid,打印出来的结果和之前相同。证明达到目的。
测试代码:
NSString * uuid= [UUID getUUID];
NSLog(@"uuid=%@",uuid);
测试结果:
uuid=19AAB430-9CB8-4325-ACC5-D7D386B68960