iOS获取UUID(唯一不变哦)

获取UUID的方法有很多，但是都会因为各种原因改变

/**  卸载应用重新安装后会不一致*/
+ (NSString *)getUUID{
    CFUUIDRef uuid = CFUUIDCreate(NULL);
    NSString *UUID = (__bridge_transfer NSString *)CFUUIDCreateString(NULL, uuid);
    CFRelease(uuid);
    return UUID;
}

/**  卸载应用重新安装后会不一致*/
+ (NSString *)getUUID{
    return [UIDevice currentDevice].identifierForVendor.UUIDString;;
}

/** 不会因为应用卸载改变 
  * 但是用户在设置-隐私-广告里面限制广告跟踪后会变成@"00000000-0000-0000-0000-000000000000"
  * 重新打开后会变成另一个，还原广告标识符也会变
  */
+ (NSString *)getUUID{
    return [[[ASIdentifierManager sharedManager] advertisingIdentifier] UUIDString];
}

作为设备唯一的标识符，一言不合就变了肯定是不行的呀

在产品汪的逼迫下，在我不懈的努力下，我终于找到一个可以一直保持一致的方法。第一次获取成功后保存到钥匙串，然后每次使用都通过钥匙串去拿。

第一步，打开应用的钥匙串权限

Target - Capabilities - KeychainSharing - ON

第二步，复制粘贴代码，懒得复制的可以去我的Github上直接下载

先粘.h文件

#import <Foundation/Foundation.h>

@interface KeyChainStore : NSObject
+ (void)save:(NSString*)service data:(id)data;
+ (id)load:(NSString*)service;
+ (void)deleteKeyData:(NSString*)service;
@end

再粘.m文件

#import "KeyChainStore.h"

@implementation KeyChainStore

+ (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 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

第三步，使用(直接调这个方法就可以了)

/**  获取UUID*/
+ (NSString *)getUUIDByKeyChain{
    // 这个key的前缀最好是你的BundleID
    NSString*strUUID = (NSString*)[KeyChainStore load:@"com.mycompany.myapp.usernamepassword"];
    //首次执行该方法时，uuid为空
    if([strUUID isEqualToString:@""]|| !strUUID)
    {
        // 获取UUID 这个是要引入<AdSupport/AdSupport.h>的
        strUUID = [[[ASIdentifierManager sharedManager] advertisingIdentifier] UUIDString];
        
        if(strUUID.length ==0 || [strUUID isEqualToString:@"00000000-0000-0000-0000-000000000000"])
        {
            //生成一个uuid的方法
            CFUUIDRef uuidRef= CFUUIDCreate(kCFAllocatorDefault);
            strUUID = (NSString*)CFBridgingRelease(CFUUIDCreateString(kCFAllocatorDefault,uuidRef));
            CFRelease(uuidRef);
        }
        
        //将该uuid保存到keychain
        [KeyChainStore save:@"com.mycompany.myapp.usernamepassword" data:strUUID];
    }
    return strUUID;
}

无论你怎么折腾都会保证同一设备每次获取到的UUID都是一致的，卸载应用，开启广告限制跟踪，系统升级都不会有影响。越狱刷机这种骚操作我没有测过，即使有问题，感觉这些调皮的用户也可以忽略了，因为这个已经是目前最好的解决办法了，如果大家有什么更好的解决方案，还请评论区指正。

参考资料：https://blog.youkuaiyun.com/wsdxsYB/article/details/51773494