本文主要是介绍iOS8 Touch ID api接口调用，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
Touch ID简介
Touch ID是苹果公司提供的一种将指纹用作密码的简便方式。只需轻触i主屏幕按钮，就能激活Touch ID传感器。主屏幕按钮周围的钢圈检测手指通知 Touch ID读取指纹。Touch ID 不会储存指纹的任何图像。它只存储指纹的数学表达式。
Touch ID的指纹数据存储在A7处理器的一个叫"secure enclave"协处理器上，唯一的Touch ID指纹识别器与唯一单独的A7处理器匹配。也就是说你将Touch ID拆开装到别的iPhone 5s上，Touch ID是无法使用的，因为它无法读取到A7处理器上的指纹数据。
Touch ID接口
使用Touch ID需要导入LocalAuthentication.framework，必须在装有iOS8的真机设备才能编译通过。
判断当前是否有可用的Touch ID
- (BOOL)canEvaluatePolicy { LAContext *context = [[LAContext alloc] init]; NSError *error; BOOL success; // test if we can evaluate the policy, this test will tell us if Touch ID is available and enrolled success = [context canEvaluatePolicy: LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]; return success; } 判断[context canEvaluatePolicy:error:]；判断当前是否有可用Touch ID，设备没有设备没有TouchID或者TouchID未开启返回false，有TouchID并开启返回true.
调用显示验证界面
- (void)evaluatePolicy { LAContext *context = [[LAContext alloc] init]; __block NSString *msg; // show the authentication UI with our reason string [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:NSLocalizedString(@"UNLOCK_ACCESS_TO_LOCKED_FATURE", nil) reply: ^(BOOL success, NSError *authenticationError) { if (success) { msg =[NSString stringWithFormat:@"EVALUATE_POLICY_SUCCESS"]; } else { msg = [NSString stringWithFormat:@"EVALUATE_POLICY_WITH_ERROR : %@", authenticationError]; } UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:msg message:nil delegate:nil cancelButtonTitle:@"ok" otherButtonTitles:nil]; [alertView show]; }]; }
调用[contextevaluatePolicy:localizedReason:reply]可以显示验证界面，验证完毕后有一个回调。苹果官方文档规定第二个参数localizedReason一定要(shoudbe)使用用户的当前语言呈现。
真机演示(演示指纹识别成功的例子)
测试用的代码片段
- (void)viewDidLoad
{ [super viewDidLoad]; [self.view setBackgroundColor:[UIColor whiteColor]]; UIButton* btn = [[UIButton alloc] init]; [btn setTitle:@"push me!" forState:UIControlStateNormal]; CGRect frame = CGRectMake(self.view.frame.size.width/2 - 60., self.view.frame.size.height/2, 120., 80.); [btn setFrame:frame]; [btn addTarget:self action:@selector(showTouchId) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:btn]; } - (void)showTouchId
{ if ([self canEvaluatePolicy]) { [self evaluatePolicy]; } else { UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"5s ok?" message:nil delegate:nil cancelButtonTitle:@"ok" otherButtonTitles:nil]; [alertView show]; }
} #pragma mark - Tests - (BOOL)canEvaluatePolicy
{ LAContext *context = [[LAContext alloc] init]; NSError *error; BOOL success; // test if we can evaluate the policy, this test will tell us if Touch ID is available and enrolled success = [context canEvaluatePolicy: LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]; return success;
} - (void)evaluatePolicy
{ LAContext *context = [[LAContext alloc] init]; __block NSString *msg; // show the authentication UI with our reason string [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:NSLocalizedString(@"UNLOCK_ACCESS_TO_LOCKED_FATURE", nil) reply: ^(BOOL success, NSError *authenticationError) { if (success) { msg =[NSString stringWithFormat:@"EVALUATE_POLICY_SUCCESS"]; } else { msg = [NSString stringWithFormat:@"EVALUATE_POLICY_WITH_ERROR : %@", authenticationError]; } UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:msg message:nil delegate:nil cancelButtonTitle:@"ok" otherButtonTitles:nil]; [alertView show]; }]; }这篇关于iOS8 Touch ID api接口调用的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
