class ViewController: UIViewController {

  override func viewDidLoad() {
    super.viewDidLoad()

    TouchIdManager.touchIdWithHand(fallBackTitle: "", succeed: { 
      print("解锁成功")
    }) { (error) in
      print(error.localizedDescription) 
    }

    print(TouchIdManager.IsSupportTouchID)

  }
}

import LocalAuthentication
class TouchIdManager {

  /// 指纹解锁
  ///
  /// - Parameters:
  ///  - fallBackTitle: Allows fallback button title customization. A default title "Enter Password" is used when
  ///       this property is left nil. If set to empty string, the button will be hidden
  ///  - succeed: 解锁成功的回调
  ///  - failed: 解锁失败的回调
  class func touchIdWithHand(fallBackTitle: String?, succeed: @escaping () -> (), failed: @escaping (_ error: LAError) -> ()) {

    guard self.IsSupportTouchID else {
      print("设备不支持TouchID 或未开启TouchID ")
      return
    }

    let context = LAContext()
    context.localizedFallbackTitle = fallBackTitle
    let reason = "验证指纹，完成支付"
    context.evaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, localizedReason: reason, reply: { (isSuccess, err) in

      OperationQueue.main.addOperation({

        guard isSuccess == true, err == nil else {
          let laerror = err as! LAError
          failed(laerror)
//          switch laerror.code {
//          case LAError.authenticationFailed: 
//            print("连续三次输入错误，身份验证失败。")
//          case LAError.userCancel: 
//            print("用户点击取消按钮。")
//          case LAError.userFallback: 
//            print("用户点击输入密码。")
//          case LAError.systemCancel: 
//            print("系统取消")
//          case LAError.passcodeNotSet: 
//            print("用户未设置密码")
//          case LAError.touchIDNotAvailable: 
//            print("touchID不可用")
//          case LAError.touchIDNotEnrolled: 
//            print("touchID未设置指纹")
//          default: break
//          }

          return
        }
        succeed()
      })
    })
  }

  /// 检查手机 TouchID 功能是否开启或可以使用
  class var IsSupportTouchID: Bool {
    get {
      let context = LAContext()
      var error :NSError?
      let isSupport = context.canEvaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, error: &error)
      return isSupport
    }
  }  
}

switch LAError(rawValue: error!.code) {

          case .Some(LAError.AuthenticationFailed):
            print("连续三次输入错误，身份验证失败。")
          case .Some(LAError.UserCancel):
            print("用户点击取消按钮。")
          case .Some(LAError.UserFallback):
            print("用户点击输入密码。")
          case .Some(LAError.SystemCancel):
            print("系统取消")
          case .Some(LAError.PasscodeNotSet):
            print("用户未设置密码")
          case .Some(LAError.TouchIDNotAvailable):
            print("touchID不可用")
          case .Some(LAError.TouchIDNotEnrolled):
            print("touchID未设置指纹")
          default:
            break
          }