获取设备唯一标识符的方法

开发中经常需要获取设备的唯一标识符，app的更新迭代，删除，系统升级等，都不会影响keychain数据中的保存（系统恢复出厂设置等，恢复型操作除外），所以Keychain显得尤为重要，

1.将Keychain Sharing按钮打开

2.

#import <Foundation/Foundation.h>

@interface UUID : NSObject

+(NSString*)getUUID;

@end

#import "UUID.h"

#import "KeyChainStore.h"

@implementation UUID

+(NSString*)getUUID {

    NSString *strUUID =(NSString*)[KeyChainStore load:@"com.company.app.usernamepassword"];

    //首次执行该方法时，uuid为空

    if([strUUID isEqualToString:@""]|| !strUUID){

             //生成一个uuid的方法

            CFUUIDRef uuidRef= CFUUIDCreate(kCFAllocatorDefault);

             strUUID =(NSString*)CFBridgingRelease(CFUUIDCreateString(kCFAllocatorDefault,uuidRef));

            //将该uuid保存到keychain

            [KeyChainStore save:@"com.company.app.usernamepassword" data:strUUID];

        }

        return strUUID;

}

@end

3.

#import <Foundation/Foundation.h>

@interface KeyChainStore : NSObject

+(void)save:(NSString*)service data:(id)data;

+(id)load:(NSString*)service;

+(void)deleteKeyData:(NSString*)service;

@end

#import "KeyChainStore.h"

@implementation KeyChainStore

+(NSMutableDictionary*)getKeychainQuery:(NSString*)service {

    return[NSMutableDictionary dictionaryWithObjectsAndKeys:

            (id)kSecClassGenericPassword,(id)kSecClass,

            service,(id)kSecAttrService,

            service,(id)kSecAttrAccount,

            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 searchdictionary(Attention:the data format)

    [keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data]forKey:(id)kSecValueData];

    //Add item to keychain with the searchdictionary

    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 areexpecting only a single attribute to be returned(the password)wecan 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:(__bridge NSData*)keyData];

        }@catch(NSException *e){

                NSLog(@"Unarchiveof %@ failed: %@",service,e);

        }@finally{

        }

    }

    if(keyData)

        CFRelease(keyData);

    return ret;

}

+(void)deleteKeyData:(NSString*)service {

    NSMutableDictionary*keychainQuery =[self getKeychainQuery:service];

    SecItemDelete((CFDictionaryRef)keychainQuery);

}

@end

4.在需要获取设备唯一标识符的地方导入以下两个头文件，再调用 [UUID getUUID]方法即可

#import "UUID.h"

#import "KeyChainStore.h"

params[@"imei"]=[UUID getUUID];