iOS 获取设备唯一标示符

记录设备标示，即使应用卸载后再安装也可重新识别的情况，在这写一种实现方式——读取设备的UUID（Universally Unique Identifier）并通过KeyChain记录。
获取uniqueIdentifier或者MAC地址被苹果认为是不合法的
这里用到三方库
SSKeyChains.SSKeyChains
附上github地址：https://github.com/soffes/sskeychain
实现代码如下，导入工程后，添加头文件，使用类名调用这一方法获取

+ (NSString *)getDeviceId
{
NSString * currentDeviceUUIDStr = [SSKeychain passwordForService:@" "account:@"uuid"];
if (currentDeviceUUIDStr == nil || [currentDeviceUUIDStr isEqualToString:@""])
{
NSUUID * currentDeviceUUID  = [UIDevice currentDevice].identifierForVendor;
currentDeviceUUIDStr = currentDeviceUUID.UUIDString;
currentDeviceUUIDStr = [currentDeviceUUIDStr stringByReplacingOccurrencesOfString:@"-" withString:@""];
currentDeviceUUIDStr = [currentDeviceUUIDStr lowercaseString];
[SSKeychain setPassword: currentDeviceUUIDStr forService:@" "account:@"uuid"];
}
return currentDeviceUUIDStr;
}