iOS 中 Touch ID得用法

import LocalAuthentication

var myContext = LAContext()
        var error: NSError?
        var localizedReasonString = "认证提示信息"
        
        if myContext.canEvaluatePolicy(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, error: &error) {
            //第三个参数为闭包
            myContext.evaluatePolicy(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, localizedReason: localizedReasonString, reply: {
                (success: Bool, error: NSError!) in
                
                    if success {
                        //认证成功
                    } else {
                        //认证失败，错误原因在error中
                    }
                })
        } else {
            //不能够进行认证，错误信息在error中
        }

LAContext *myContext = [[LAContext alloc] init];
        NSError *authError = nil;
        NSString *myLocalizedReasonString = "认证提示信息";
        
        if ([myContext canEvaluatePolicy: LAPolicyDeviceOwnerAuthenticationWithBiometrics error: &authError]) {
            [myContext evaluatePolicy: LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason: myLocalizedReasonString reply: ^(BOOL success, NSError *error) {
                if (success) {
                //认证成功
                } else {
                //认证失败，error里包含错误信息
                }
                }]
        } else {
            //不能进行认证， authError中包含错误信息
        }