前言:IOS7中,UDID和MAC地址等设备唯一标识方法都被淘汰,但开发中,业务往往需要这个唯一标识,经过研究,还没找到可以完全替代UDID和MAC地址的方法,但退而求其次,找到了将UUID作为UDID使用的办法,UUID保证了序列号的唯一性,所以剩下问题就是解决如何保存UUID的问题了,经过调研,利用KeyChain可以保存数据,并且APP删除,重启机器情况下仍然不影响保存的数据,但如果用户刷系统,这种办法就不行了。下面奉上代码:
项目要引入:Security.framework
#import <UIKit/UIKit.h>
#import "KeychainHelper.h"
@interface ViewController : UIViewController
@end
#import "ViewController.h"
NSString * const KEY_DIC = @"com.company.app.dic";
NSString * const KEY_UDID = @"com.company.app.kUdidTest";
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
}
- (NSString*) uuid
{
CFUUIDRef puuid = CFUUIDCreate(nil);
CFStringRef uuidString = CFUUIDCreateString(nil, puuid);
NSString *result = (NSString *)CFStringCreateCopy(NULL, uuidString);
CFRelease(puuid);
CFRelease(uuidString);
return [result autorelease];
}
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
NSMutableDictionary *dic = (NSMutableDictionary *)[KeychainHelper load:KEY_DIC];
NSString *udid = [dic objectForKey:KEY_UDID];
if (udid)
{
NSLog(@"udid:%@", udid);
}
if (!udid)
{
NSLog(@"save");
NSMutableDictionary *dic = [NSMutableDictionary dictionary];
[dic setObject:[self uuid] forKey:KEY_UDID];
[KeychainHelper save:KEY_DIC data:dic];
}
}
@end
-------------------分割线---------------------
#import <Foundation/Foundation.h>
#import <Security/Security.h>
@interface KeychainHelper : NSObject
+ (void) save:(NSString *)service data:(id)data;
+ (id) load:(NSString *)service;
+ (void) deleteData:(NSString *)service;
@end
#import "KeychainHelper.h"
@implementation KeychainHelper
+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service
{
return [NSMutableDictionary dictionaryWithObjectsAndKeys:
(id)kSecClassGenericPassword,(id)kSecClass,
service, (id)kSecAttrService,
service, (id)kSecAttrAccount,
(id)kSecAttrAccessibleAfterFirstUnlock,(id)kSecAttrAccessible,
nil];
}
+ (void)save:(NSString *)service data:(id)data
{
//Get search dictionary
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
//Delete old item before add new item
SecItemDelete((CFDictionaryRef)keychainQuery);
//Add new object to search dictionary(Attention:the data format)
[keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(id)kSecValueData];
//Add item to keychain with the search dictionary
SecItemAdd((CFDictionaryRef)keychainQuery, NULL);
}
+ (id)load:(NSString *)service
{
id ret = nil;
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
//Configure the search setting
//Since in our simple case we are expecting only a single attribute to be returned (the password) we can set the attribute kSecReturnData to kCFBooleanTrue
[keychainQuery setObject:(id)kCFBooleanTrue forKey:(id)kSecReturnData];
[keychainQuery setObject:(id)kSecMatchLimitOne forKey:(id)kSecMatchLimit];
CFDataRef keyData = NULL;
if (SecItemCopyMatching((CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
@try {
ret = [NSKeyedUnarchiver unarchiveObjectWithData:(NSData *)keyData];
} @catch (NSException *e) {
NSLog(@"Unarchive of %@ failed: %@", service, e);
} @finally {
}
}
if (keyData)
CFRelease(keyData);
return ret;
}
+ (void)deleteData:(NSString *)service
{
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
SecItemDelete((CFDictionaryRef)keychainQuery);
}
@end
这样就实现了即使删除App,当再次安装后还保存上次的数据不丢失。