IOS8 TouchID使用介绍

浏览数：18 / 时间：2015年06月11日

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

[objc] view plain copy

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

2、调用TouchID识别接口

[objc] view plain copy

- (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

[objc] view plain copy

{
/// 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：

[objc] view plain copy

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];