IOS8 TouchID使用介绍

本文转载至 http://blog.csdn.net/jinkaiouyang/article/details/35555123

IOS8将指纹识别技术开放出来了。我们能够利用用户设置的touch ID来进行用户鉴权。

TouchID的API主要集成在LocalAuthentication.framework中。将改framework加入到工程中，并且需要iPhone5S和IOS8系统的支持，就能使用TouchID的API

了。



TouchID的API非常简单：

1、使用之前，需要先判断TouchID是否支持

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- (BOOL)canEvaluatePolicy:(LAPolicy)policy error:(NSError * __autoreleasing *)error;

2、调用TouchID识别接口

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- (void)evaluatePolicy:(LAPolicy)policy localizedReason:(NSString *)localizedReason reply:(void(^)(BOOL success, NSError *error))reply;

policy枚举，表示需要使用到的权限，目前只有一个Biometrics，意思指的就是TouchID

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{

/// Device owner was authenticated using a biometric method. Biometrics (Touch ID) is required.

/// If Touch ID is not enabled, policy evaluation fails.

LAPolicyDeviceOwnerAuthenticationWithBiometrics = kLAPolicyDeviceOwnerAuthenticationWithBiometrics

} NS_ENUM_AVAILABLE(10_10, 8_0);

localizedReason

使用TouchID的理由，会出现在弹框中，提示用户。这个字段必须填写且不为nil或空值，否则会抛NSInvalidArgumentException异常，

(void(^)(BOOL success,NSError *error))

TouchID输入的结果回调。使用block方式。

示例代码：

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LAContext *context = [[LAContext alloc] init];

NSError *contextError = nil;

NSString *localizedReasonString = @"Need Authorize";

if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&contextError]) {

[context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics

localizedReason:localizedReasonString

reply:^(BOOL success, NSError *error) {

NSString *title, *message;

if (success) {

title = @"Authorize Success";

message = nil;

} else {

title = @"Authorize Faied";

message = error.localizedFailureReason;

}

UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:title

message:message

delegate:nil

cancelButtonTitle:@"OK"

otherButtonTitles:nil];

[alertView show];

}];

} else {

UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Context Error"

message:contextError.localizedFailureReason

delegate:nil

cancelButtonTitle:@"OK"

otherButtonTitles:nil];

[alertView show];