獲取uuid

介紹一個輕量級iOS安全框架：SSKeyChain   

詳細介紹：http://blog.sina.com.cn/s/blog_93f39bc20101a44t.html

SSKeyChains對蘋果安全框架API進行了簡單封裝，支援對儲存在鑰匙串中密碼、賬戶進行訪問，包括讀取、刪除和設定。SSKeyChain的作者是大名鼎鼎的SSToolkit的作者samsoffes。

獲取uuid的兩種方法：

一：鑰匙串儲存就算程式被刪除也能獲取唯一標示但是系統重灌就不一定了

+ (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;

}

二：程式的唯一標示一旦程式被刪除標示也就跟著改變了

NSString *udid = [[UIDevice currentDevice].identifierForVendor UUIDString];