iOS编程——通过UUID和KeyChain来代替Mac地址实现iOS设备的唯一标示(OC版)
很多的应用都需要用到手机的唯一标示，而且要求这个唯一标示不能因为应用app的卸载或者改变而变化。
在iOS7以前是可以通过Mac地址来实现这个功能的，但是iOS7(包含)以后是无法获得Mac地址的；苹果官方推荐使用UUID，但是每次随着APP的卸载重装，UUID会随之发生变化，那该如何处理呢？
我们需要一个能在app卸载重装后不会改变的值，而keyChain恰巧就可以做到。配合UUID就可以实现了！让我们来分析下：
1.我们首先需要导入Security.frameWork（keychain依赖它），然后需要一个keychain管理器，一个uuid管理器，文件组成如下：
2.首先来看MyKeychainManager,其实就是对keychain的增、删、改、查，类似于数据库的处理。
先通过.h文件来开放下增、删、改、查四个接口：
#import <Foundation/Foundation.h> @interface MyKeyChainManager : NSObject + (NSMutableDictionary *)getKeychainQuery:(NSString *)service; + (void)save:(NSString *)service data:(id)data; + (id)load:(NSString *)service; + (void)delete:(NSString *)service; @end
.m文件实现接口，keychain的使用网上很多，直接贴代码了：
#import "MyKeyChainManager.h"
@implementation MyKeyChainManager : NSObject
+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
return [NSMutableDictionary dictionaryWithObjectsAndKeys:
(__bridge_transfer id)kSecClassGenericPassword,(__bridge_transfer id)kSecClass,
service, (__bridge_transfer id)kSecAttrService,
service, (__bridge_transfer id)kSecAttrAccount,
(__bridge_transfer id)kSecAttrAccessibleAfterFirstUnlock,(__bridge_transfer 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((__bridge_retained CFDictionaryRef)keychainQuery);
//Add new object to search dictionary(Attention:the data format)
[keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(__bridge_transfer id)kSecValueData];
//Add item to keychain with the search dictionary
SecItemAdd((__bridge_retained CFDictionaryRef)keychainQuery, NULL);
}
+ (id)load:(NSString *)service {
id ret = nil;
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
//Configure the search setting
[keychainQuery setObject:(id)kCFBooleanTrue forKey:(__bridge_transfer id)kSecReturnData];
[keychainQuery setObject:(__bridge_transfer id)kSecMatchLimitOne forKey:(__bridge_transfer id)kSecMatchLimit];
CFDataRef keyData = NULL;
if (SecItemCopyMatching((__bridge_retained CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
@try {
ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge_transfer NSData *)keyData];
} @catch (NSException *e) {
NSLog(@"Unarchive of %@ failed: %@", service, e);
} @finally {
}
}
return ret;
}
+ (void)delete:(NSString *)service {
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
SecItemDelete((__bridge_retained CFDictionaryRef)keychainQuery);
}
@end
3.再来看下MyUUIDManager文件，实现的是对UUID的增、删、改、查，其中save既是增也是改：
#import <Foundation/Foundation.h> @interface MyUUIDManager: NSObject +(void)saveUUID:(NSString *)uuid; +(NSString *)getUUID; +(void)deleteUUID; @end
.m文件来实现它：
#import "MyUUIDManager.h"
#import "MyKeyChainManager.h" @implementation MyUUIDManager static NSString * const KEY_IN_KEYCHAIN = @"com.myuuid.uuid"; +(void)saveUUID:(NSString *)uuid{
if (uuid && uuid.length > ) {
[MyKeyChainManager save:KEY_IN_KEYCHAIN data:uuid];
}
} +(NSString *)getUUID{
//先获取keychain里面的UUID字段，看是否存在
NSString *uuid = (NSString *)[MyKeyChainManager load:KEY_IN_KEYCHAIN]; //如果不存在则为首次获取UUID，所以获取保存。
if (!uuid || uuid.length == ) {
CFUUIDRef puuid = CFUUIDCreate( nil ); CFStringRef uuidString = CFUUIDCreateString( nil, puuid ); uuid = [NSString stringWithFormat:@"%@", uuidString]; [self saveUUID:uuid]; CFRelease(puuid); CFRelease(uuidString);
} return uuid;
} +(void)deleteUUID{
[MyKeyChainManager delete:KEY_IN_KEYCHAIN];
} @end
4.测试一下：
NSString *uuid = [MyUUIDManager getUUID];
NSLog(@"uuid: %@",uuid);
-- ::07.641 MyTest[:] uuid: 839E055B-09A5-42E1-A46C-DF4481E23333
5.把app删除掉重新安装一下，再打印一下：
-- ::37.122 MyTest[:] uuid: 839E055B-09A5-42E1-A46C-DF4481E23333