iOS开发 生成设备唯一标识符，卸载重装也不会改变

iOS开发的时候，有时候需要设备的唯一标识符，但是uuid在卸载重装或者更新之后会变动，无法保持不变，这个时候我们使用keychain钥匙串就可以实现了，app卸载重装了也是保持不变，因为这个存储的唯一标识符是放在手机的内存里面，不跟着app走，具体直接上代码，两个文件就行了

1.保存uuid的keychain的文件

.h

#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface CMKeyChain : NSObject

+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service ;
 
+ (void)save:(NSString *)service data:(id)data;
 
+ (id)load:(NSString *)service;
 
+ (void)delete:(NSString *)service;

@end

.m

#import "CMKeyChain.h"
 
@implementation CMKeyChain
+ (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
    CFDictionaryRef aRef = (__bridge_retained CFDictionaryRef)keychainQuery;
    SecItemDelete(aRef/*(__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(aRef/*(__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

2.管理uuid的文件

.h

#import <Foundation/Foundation.h>
 
@interface CMUUIDManager : NSObject
 
+(void)saveUUID:(NSString *)uuid;
 
+(id)readUUID;
 
+(void)deleteUUID;
 
@end

.m

#import "CMUUIDManager.h"
#import "CMKeyChain.h"
 
@implementation CMUUIDManager
static NSString * const KEY_IN_KEYCHAIN = @"com.xxx.UUID";
static NSString * const KEY_UUID = @"com.xxx.UUID.uuid";

+(void)saveUUID:(NSString *)uuid
{
    NSMutableDictionary *usernameUuidPairs = [NSMutableDictionary dictionary];
    [usernameUuidPairs setObject:uuid forKey:KEY_UUID];
    [CMKeyChain save:KEY_IN_KEYCHAIN data:usernameUuidPairs];
}
 
+(id)readUUID
{
    NSMutableDictionary *usernameUuidPairs = (NSMutableDictionary *)[CMKeyChain load:KEY_IN_KEYCHAIN];
    return [usernameUuidPairs objectForKey:KEY_UUID];
}
 
+(void)deleteUUID
{
    [CMKeyChain delete:KEY_IN_KEYCHAIN];
}
@end

以上俩文件结合就可以实现iOS手机设备唯一标识符，并且卸载重装也不会变动