适用于从iOS8迁移的用户的Touch-id手指代码

import LocalAuthentication

func authenticateUser() {
    let context = LAContext()
    var error: NSError?

    // 检查设备是否支持Touch ID
    if context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) {
        let reason = "通过Touch ID验证您的身份"
        
        context.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: reason) { success, authenticationError in
            DispatchQueue.main.async {
                if success {
                    // Touch ID验证成功，执行相应操作
                } else {
                    // Touch ID验证失败，显示错误信息
                    if let error = authenticationError as? LAError {
                        let message = self.errorMessageForLAErrorCode(errorCode: error.code)
                        // 显示错误信息给用户
                    }
                }
            }
        }
    } else {
        // 设备不支持Touch ID，显示错误信息给用户
    }
}

func errorMessageForLAErrorCode(errorCode: Int) -> String {
    var message = ""
    
    switch errorCode {
    case LAError.authenticationFailed.rawValue:
        message = "验证失败"
    case LAError.userCancel.rawValue:
        message = "用户取消验证"
    case LAError.userFallback.rawValue:
        message = "用户选择输入密码"
    case LAError.biometryNotAvailable.rawValue:
        message = "Touch ID不可用"
    case LAError.biometryNotEnrolled.rawValue:
        message = "未设置Touch ID"
    case LAError.biometryLockout.rawValue:
        message = "Touch ID被锁定"
    default:
        message = "Touch ID验证失败"
    }
    
    return message
}