iOS 钥匙串保存UUID

KeychainItemWrapper * wrapper = [[KeychainItemWrapper alloc]initWithIdentifier:@"AACCA" accessGroup:nil];
id kUsernameKey = (__bridge id)kSecAttrAccount;
id kPasswordKey = (__bridge id)kSecValueData;
NSString * username = [wrapper objectForKey:kUsernameKey];
NSString * passwordStr = [wrapper objectForKey:kPasswordKey];

if (passwordStr.length) {
NSLog(@">>>>>>>老用户");
NSLog(@"username = %@",username);
NSLog(@"password = %@",passwordStr);
//  [wrapper resetKeychainItem];
//清空设置

}else{
NSLog(@">>>>>>>新用户");
[wrapper setObject:result forKey:kPasswordKey];
[wrapper setObject:@"Sayimo" forKey:kUsernameKey];
//保存账号密码到我所建立的这个钥匙串，而每个app只能创建一个钥匙串账户，重复创建会崩溃，必须清空设置后才可以重新写入新的钥匙串账号，账户密码。
}

//虽然我也不知道怎么实现的，但是TMD就这么现实了！！！！我惊呆了！！！！
引入Security.framework   #import "KeychainItemWrapper.h"

配合UUID
CFUUIDRef puuid = CFUUIDCreate(nil);
CFStringRef uuidString = CFUUIDCreateString(nil, puuid);
NSString * result = CFBridgingRelease(CFStringCreateCopy( NULL, uuidString));
lab.text = result;
NSLog(@">>>>>>result = %@",result);