iOS8 Touch ID 获取错误 : Pending UI mechanism already set

Question

错误描述如下:

Error Domain=com.apple.LocalAuthentication Code=-1000 "Pending UI mechanism already set." UserInfo=0x17406b0c0 {NSLocalizedDescription=Pending UI mechanism already set.}

我也在尝试 Apple 的 Sample Example 应用程序并遇到同样的错误。以前它工作正常，但它突然停止工作并且不工作。请帮忙。

我正在使用装有 iOS 8.1 的 iPhone 6

Answer 1

这段代码对我来说效果很好。

LAContext *myContext = [[LAContext alloc] init];
NSError *authError = nil;
NSString *myLocalizedReasonString = @"String explaining why app needs authentication";

if ([myContext canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&authError]) {
    [myContext evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
              localizedReason:myLocalizedReasonString
                        reply:^(BOOL success, NSError *error) {
                            if (success) {
                                // User authenticated successfully, take appropriate action
                                NSLog(@"User authenticated successfully, take appropriate action");
                            } else {
                                // User did not authenticate successfully, look at error and take appropriate action
                                NSLog(@"User did not authenticate successfully, look at error and take appropriate action");
                            }
                        }];
} else {
    // Could not evaluate policy; look at authError and present an appropriate message to user
    NSLog(@"Could not evaluate policy: %@",authError);
}

不要忘记导入本地身份验证框架 <LocalAuthentication/LAContext.h>.希望这会解决您的问题。