获取UUID两种方法，并让UUID唯一的方法

方法一、

CFUUIDRefpuuid = CFUUIDCreate(nil);

    CFStringRefuuidString = CFUUIDCreateString(nil, puuid);

    NSString*result = (NSString*)CFBridgingRelease(CFStringCreateCopy(NULL, uuidString));

    CFRelease(puuid);

    CFRelease(uuidString);

return  result;

方法二、

NSString*myUUIDStr = [[[UIDevice currentDevice] identifierForVendor] UUIDString]; 

UUID 重装后改变；

为了确保UUID唯一， 需要使用更为安全的keychain

下载SSKeychain

#import "SSKeychain.h"

#pragma mark- 获取UUID

- (NSString *)getIOSUUID

{

    NSString *retrieveuuid = [SSKeychain passwordForService:@"xxxxx" account:@"uuid"];

    

    if ( retrieveuuid == nil || [retrieveuuid isEqualToString:@""]){

        CFUUIDRef uuid = CFUUIDCreate(NULL);

        assert(uuid != NULL);

        CFStringRef uuidStr = CFUUIDCreateString(NULL, uuid);

        

        retrieveuuid = [NSString stringWithFormat:@"%@", uuidStr];

        

        [SSKeychain setPassword:retrieveuuid forService:@"xxxxx" account:@"uuid"];

    }

    NSLog(@"UUID: %@", retrieveuuid);

    return retrieveuuid;

}