【C# AT Lib】3：AT Command

最新推荐文章于 2025-02-21 19:02:05 发布

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本文介绍了在C#中构建AT Command框架的过程，包括定义ResultCode枚举、ResponseExpectation类来设置期望响应，以及AtCommand和AtCommandBuilder类用于简化命令构造。

我们在设计AT Command，需要把期望AT Response是什么样的信息放进去，这样在底层进行AT通讯的时候就可以自动加入Retry功能。

定义ResultCode枚举变量

    public enum ResultCode
    {
        OK,
        ERROR
    }

定义ResponseExpectation类

告知AT Response需不需要包含期望的Result Code
告知AT Response中对于总体Data Lines有什么期许
告知AT Response中对于某一行Data Line有什么期许

    public class ResponseExpectation
    {
        public ResultCode? ExpectedResultCode { get; set; }

        public Predicate<string[]> AllDataLinesPredicate { get; set; }

        public Predicate<string>[] AnyDataLinePredicates { get; set; }

        public bool Accepts(ResultCode? resultCode, string[] dataLines)
        {
            return Accepts(resultCode) && Accepts(dataLines);
        }

        private bool Accepts(ResultCode? resultCode)
        {
            if (!ExpectedResultCode.HasValue)
                return true;

            return ExpectedResultCode == resultCode;
        }

        private bool Accepts(string[] dataLines)
        {
            if (!AllDataLinesPredicateAccepts(dataLines))
                return false;

            if (!AnyDataLinePredicatesAccept(dataLines))
                return false;

            return true;
        }

        private bool AllDataLinesPredicateAccepts(string[] dataLines)
        {
            return AllDataLinesPredicate == null || AllDataLinesPredicate(dataLines);
        }

        private bool AnyDataLinePredicatesAccept(string[] dataLines)
        {
            return AnyDataLinePredicates.All(
                dataLinePredicate => dataLines.Any(line => dataLinePredicate(line)));
        }
    }

定义AtCommand类

    public class AtCommand
    {
        public string RawCommand { get; set; }

        public string SuffixedRawCommand
        {
            get
            {
                const string suffix = "\r";
                return RawCommand + suffix;
            }
        }

        public ResponseExpectation ResponseExpectation { get; set; }

        public override string ToString()
        {
            return RawCommand;
        }
    }

定义AtCommandBuilder类

因为AtCommand对象在构造的时候相对有些复杂，于是我们用一个单独的AtCommandBuilder类去帮助构造AtCommand对象。

    public class AtCommandBuilder
    {
        private string _rawCommand;
        private ResultCode? _expectedResultCode;
        private Predicate<string[]> _allDataLinesPredicate;
        private readonly List<Predicate<string>> _anyDataLinePredicates = new List<Predicate<string>>();

        public AtCommandBuilder WithRawCommand(string rawCommand)
        {
            if (string.IsNullOrWhiteSpace(rawCommand))
                throw new ArgumentException("Raw command can't be Null or WhiteSpace.", "rawCommand");

            _rawCommand = rawCommand.Trim();

            return this;
        }

        public AtCommandBuilder WithExpectedResultCode(ResultCode expectedResultCode)
        {
            _expectedResultCode = expectedResultCode;
            return this;
        }

        public AtCommandBuilder WithExpectedOkResultCode()
        {
            return WithExpectedResultCode(ResultCode.OK);
        }

        public AtCommandBuilder WithAllDataLinesPredicate(Predicate<string[]> predicate)
        {
            _allDataLinesPredicate = predicate;
            return this;
        }

        public AtCommandBuilder WithAnyDataLinePredicate(Predicate<string> predicate)
        {
            _anyDataLinePredicates.Add(predicate);
            return this;
        }

        public AtCommandBuilder WithAnyDataLinePredicateStartsWith(string startCriterion)
        {
            return WithAnyDataLinePredicate(
                dateLine => dateLine.StartsWith(startCriterion, StringComparison.CurrentCultureIgnoreCase));
        }

        public AtCommand Build()
        {
            return new AtCommand
            {
                RawCommand = _rawCommand,
                ResponseExpectation = new ResponseExpectation
                {
                    ExpectedResultCode = _expectedResultCode,
                    AllDataLinesPredicate = _allDataLinesPredicate,
                    AnyDataLinePredicates = _anyDataLinePredicates.ToArray()
                }
            };
        }
    }