基於Redis實現的驗證碼發送及校驗方案

在我們的業務中，經常存在需要通過發送驗證碼、校驗驗證碼來完成的一些業務邏輯，比如賬號註冊、找回密碼、用戶身份確認等。

在該類業務中，發送驗證碼的方式可以有各種各樣，比如最常見的手機驗證，最古老的郵箱驗證，到現在相對少見的微信公衆號、釘釘通知等；而驗證碼服務端存儲的方式也可以各式各樣，比如存儲在關係型數據庫中，當然也可以如本文標題所示，存儲在Redis中。

既然已經預見到了各式各樣的發送方式，也預見到了各式各樣的存儲方式，所以，雖然本文標題是基於Redis，但Redis其實只是其中的一種存儲方式，如果需要，我們也應該可以和方便的切換到其它存儲方式。

上代碼前，我們先看下設計中的接口關係

ICodeHelper是最終提供發送驗證碼和校驗驗證碼的最終接口，其關聯了ICodeSender和ICodeStorage，ICodeSender即爲驗證碼發送方式的約定接口，ICodeStorage則爲驗證碼服務端持久化方式的約定接口。我們可以看到ICodeSender同樣關聯了IContentFormatter，因爲作爲發送方ICodeSender其實是不知道如何將要發送的內容組織成一段完整的文本內容的，這時候就需要IContentFormatter來組織文本內容，至於繼承自IContentFormatter的IComplexContentFormatter，則只是IContentFormatter一個容器封裝，畢竟對於不同的業務類型，我們需要組織成不同的文本內容，通過IComplexContentFormatter，我們可以將不同業務類型文本內容的組織過程，分散到不同的IContentFormatter中。

下面我們來看下上述接口的規範約定，考慮到代碼的簡便性，此處我們簡單的將receiver接收方定義爲了string，而不是泛型<T>；業務標誌bizFlag爲了方便接入時無需調整代碼，所以此處也沒有將該值定義爲枚舉，而是同樣定義成了通用性最強的string。

ICodeStorage

    /// <summary>
    /// 校驗碼信息存儲接口
    /// </summary>
    public interface ICodeStorage
    {
        /// <summary>
        /// 將校驗碼進行持久化，如果接收方和業務標誌組合已經存在，則進行覆蓋
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="code">校驗碼</param>
        /// <param name="effectiveTime">校驗碼有效時間範圍</param>
        /// <returns></returns>
        Task<bool> SetCode(string receiver, string bizFlag, string code, TimeSpan effectiveTime);
        /// <summary>
        /// 校驗碼錯誤次數+1，如果校驗碼已過期，則不進行任何操作
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <returns></returns>
        Task IncreaseCodeErrors(string receiver, string bizFlag);
        /// <summary>
        /// 校驗碼發送次數週期持久化，如果接收方和業務標誌組合已經存在，則進行覆蓋
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="period">週期時間範圍</param>
        /// <returns></returns>
        Task<bool> SetPeriod(string receiver, string bizFlag, TimeSpan? period);
        /// <summary>
        /// 校驗碼週期內發送次數+1，如果週期已到，則不進行任何操作
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <returns></returns>
        Task IncreaseSendTimes(string receiver, string bizFlag);
        /// <summary>
        /// 獲取校驗碼及已嘗試錯誤次數，如果校驗碼不存在或已過期，則返回null
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <returns></returns>
        Task<Tuple<string, int>> GetEffectiveCode(string receiver, string bizFlag);
        /// <summary>
        /// 獲取校驗碼週期內已發送次數，如果週期已到或未發送過任何驗證碼，則返回0
        /// </summary>
        /// <param name="receiver"></param>
        /// <param name="bizFlag"></param>
        /// <returns></returns>
        Task<int> GetAreadySendTimes(string receiver, string bizFlag);
    }

ICodeSender，請注意IsSupport方法約定。

    /// <summary>
    /// 校驗碼實際發送接口
    /// </summary>
    public interface ICodeSender
    {
        /// <summary>
        /// 發送校驗碼內容模板
        /// </summary>
        IContentFormatter Formatter { get; }
        /// <summary>
        /// 判斷接收者是否符合發送條件，例如當前發送者只支持郵箱，而接收方爲手機號，則返回結果應當爲false
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <returns></returns>
        bool IsSupport(string receiver);
        /// <summary>
        /// 發送校驗碼信息
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="code">校驗碼</param>
        /// <param name="effectiveTime">校驗碼有效時間範圍</param>
        /// <returns></returns>
        Task<bool> Send(string receiver, string bizFlag, string code, TimeSpan effectiveTime);
    }

IContentFormatter

    /// <summary>
    /// 發送校驗碼內容模板接口
    /// </summary>
    public interface IContentFormatter
    {
        /// <summary>
        /// 將指定參數組織成待發送的文本內容
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="code">校驗碼</param>
        /// <param name="effectiveTime">校驗碼有效時間範圍</param>
        /// <returns></returns>
        string GetContent(string receiver, string bizFlag, string code, TimeSpan effectiveTime);
    }

IComplexContentFormatter

    /// <summary>
    /// 基於業務標誌的多內容模板
    /// </summary>
    public interface IComplexContentFormatter : IContentFormatter
    {
        /// <summary>
        /// 設置指定業務對應的內容模板
        /// </summary>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="formatter">內容模板</param>
        void SetFormatter(string bizFlag, IContentFormatter formatter);
        /// <summary>
        /// 移除指定業務對應的內容模板，如果沒有，則返回null
        /// </summary>
        /// <param name="bizFlag">業務標誌</param>
        /// <returns></returns>
        IContentFormatter RemoveFormatter(string bizFlag);
    }

ICodeHelper

    /// <summary>
    /// 業務校驗碼輔助接口
    /// </summary>
    public interface ICodeHelper
    {
        /// <summary>
        /// 校驗碼實際發送者
        /// </summary>
        ICodeSender Sender { get; }
        /// <summary>
        /// 校驗碼信息存儲者
        /// </summary>
        ICodeStorage Storage { get; }
        /// <summary>
        /// 發送校驗碼
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="code">校驗碼</param>
        /// <param name="effectiveTime">校驗碼有效時間範圍</param>
        /// <param name="maxSendLimit">週期內最大允許發送配置，爲null則表示無限制</param>
        /// <returns></returns>
        Task<SendResult> SendCode(string receiver, string bizFlag, string code, TimeSpan effectiveTime, PeriodLimit maxSendLimit);
        /// <summary>
        /// 驗證校驗碼是否正確
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="code">校驗碼</param>
        /// <param name="maxErrorLimit">最大允許錯誤次數</param>
        /// <returns></returns>
        Task<VerificationResult> VerifyCode(string receiver, string bizFlag, string code, int maxErrorLimit);
    }

下面則是接口約定中的一些定義的類和枚舉。

    /// <summary>
    /// 校驗碼發送週期設置
    /// </summary>
    public class PeriodLimit
    {
        /// <summary>
        /// 週期內允許的最大次數
        /// </summary>
        public int MaxLimit { get; set; }
        /// <summary>
        /// 週期時間，如果不設置，則表示無週期，此時<see cref="MaxLimit"/>代表總共只允許發送多少次
        /// </summary>
        public TimeSpan? Period { get; set; }
    }
    /// <summary>
    /// 校驗碼發送結果
    /// </summary>
    public enum SendResult
    {
        /// <summary>
        /// 發送成功
        /// </summary>
        [Description("成功")]
        Success = 0,
        /// <summary>
        /// 超出最大發送次數
        /// </summary>
        [Description("超出最大發送次數")]
        MaxSendLimit = 11,
        /// <summary>
        /// 發送失敗，指<see cref="ICodeSender"/>的發送結果爲false
        /// </summary>
        [Description("發送失敗")]
        FailInSend = 12,
        /// <summary>
        /// 無法發送，<see cref="ICodeSender.IsSupport(string)"/>結果爲false
        /// </summary>
        [Description("無法發送")]
        NotSupprot = 13,
    }
    /// <summary>
    /// 校驗碼校驗結果
    /// </summary>
    public enum VerificationResult
    {
        /// <summary>
        /// 校驗成功
        /// </summary>
        [Description("成功")]
        Success = 0,
        /// <summary>
        /// 校驗碼已過期
        /// </summary>
        [Description("校驗碼已過期")]
        Expired = 31,
        /// <summary>
        /// 校驗碼不一致，校驗失敗
        /// </summary>
        [Description("校驗失敗")]
        VerificationFailed = 32,
        /// <summary>
        /// 已經達到了最大錯誤嘗試次數，需重新發送新的校驗碼
        /// </summary>
        [Description("超出最大錯誤次數")]
        MaxErrorLimit = 33,
    }

再下來就是具體的接口實現了，當然這些實現也是通用實現

ContentFormatter

    /// <summary>
    /// 通用的內容模板
    /// </summary>
    public class ContentFormatter : IContentFormatter
    {
        private Func<string, string, string, TimeSpan, string> _func;
        /// <summary>
        /// 通用實現，這樣就無需每種業務類型都要實現<see cref="IContentFormatter"/>
        /// </summary>
        /// <param name="func">傳遞的委託，參數順序與<see cref="GetContent(string, string, string, TimeSpan)"/>一致</param>
        public ContentFormatter(Func<string, string, string, TimeSpan, string> func)
        {
            this._func = func ?? throw new ArgumentNullException(nameof(func));
        }
        /// <summary>
        /// 將指定參數組織成待發送的文本內容
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="code">校驗碼</param>
        /// <param name="effectiveTime">校驗碼有效時間範圍</param>
        /// <returns></returns>
        public string GetContent(string receiver, string bizFlag, string code, TimeSpan effectiveTime)
        {
            return this._func.Invoke(receiver, bizFlag, code, effectiveTime);
        }
    }

ComplexContentFormatter

    using System.Collections.Concurrent;
    /// <summary>
    /// 基於業務標誌的多內容模板實現
    /// </summary>
    public class ComplexContentFormatter : IComplexContentFormatter
    {
        private ConcurrentDictionary<string, IContentFormatter> _dic = new ConcurrentDictionary<string, IContentFormatter>();
        /// <summary>
        /// 設置指定業務對應的內容模板
        /// </summary>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="formatter">內容模板</param>
        public void SetFormatter(string bizFlag, IContentFormatter formatter)
        {
            if (!string.IsNullOrWhiteSpace(bizFlag) && formatter != null)
            {
                this._dic.AddOrUpdate(bizFlag, formatter, (k, v) => formatter);
            }
        }
        /// <summary>
        /// 移除指定業務對應的內容模板，如果沒有，則返回null
        /// </summary>
        /// <param name="bizFlag">業務標誌</param>
        /// <returns></returns>
        public IContentFormatter RemoveFormatter(string bizFlag)
        {
            if (!string.IsNullOrWhiteSpace(bizFlag)
                && this._dic.TryRemove(bizFlag, out IContentFormatter formatter))
            {
                return formatter;
            }
            return null;
        }
        /// <summary>
        /// 將指定參數組織成待發送的文本內容
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="code">校驗碼</param>
        /// <param name="effectiveTime">校驗碼有效時間範圍</param>
        /// <returns></returns>
        public string GetContent(string receiver, string bizFlag, string code, TimeSpan effectiveTime)
        {
            if (string.IsNullOrWhiteSpace(bizFlag))
            {
                throw new ArgumentNullException(nameof(bizFlag));
            }
            this._dic.TryGetValue(bizFlag, out IContentFormatter formatter);
            if (formatter == null)
            {
                throw new KeyNotFoundException(nameof(formatter));
            }
            return formatter.GetContent(receiver, bizFlag, code, effectiveTime);
        }
    }

CodeHelper，注意該類除了實現ICodeHelper外，還提供了一個用於生成隨機驗證碼的靜態方法GetRandomNumber。

    /// <summary>
    /// 業務校驗碼輔助接口實現
    /// </summary>
    public class CodeHelper : ICodeHelper
    {
        /// <summary>
        /// 基於接口實現，可依賴注入
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="storage"></param>
        public CodeHelper(ICodeSender sender, ICodeStorage storage)
        {
            this.Sender = sender ?? throw new ArgumentNullException(nameof(sender));
            this.Storage = storage ?? throw new ArgumentNullException(nameof(storage));
        }
        /// <summary>
        /// 校驗碼實際發送者
        /// </summary>
        public ICodeSender Sender { get; }
        /// <summary>
        /// 校驗碼信息存儲者
        /// </summary>
        public ICodeStorage Storage { get; }
        /// <summary>
        /// 發送校驗碼
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="code">校驗碼</param>
        /// <param name="effectiveTime">校驗碼有效時間範圍</param>
        /// <param name="maxSendLimit">週期內最大允許發送配置，爲null則表示無限制</param>
        public async Task<SendResult> SendCode(string receiver, string bizFlag, string code, TimeSpan effectiveTime, PeriodLimit maxSendLimit)
        {
            var result = SendResult.NotSupprot;
            if (this.Sender.IsSupport(receiver))
            {
                result = SendResult.MaxSendLimit;
                bool canSend = maxSendLimit == null;
                int sendTimes = 0;
                if (!canSend)
                {
                    sendTimes = await this.Storage.GetAreadySendTimes(receiver, bizFlag).ConfigureAwait(false);
                    canSend = sendTimes < maxSendLimit.MaxLimit;
                }
                if (canSend)
                {
                    result = SendResult.FailInSend;
                    if (await this.Sender.Send(receiver, bizFlag, code, effectiveTime).ConfigureAwait(false)
                        && await this.Storage.SetCode(receiver, bizFlag, code, effectiveTime).ConfigureAwait(false))
                    {
                        result = SendResult.Success;
                        if (maxSendLimit != null)
                        {
                            if (sendTimes == 0)
                            {
                                await this.Storage.SetPeriod(receiver, bizFlag, maxSendLimit.Period).ConfigureAwait(false);
                            }
                            else
                            {
                                await this.Storage.IncreaseSendTimes(receiver, bizFlag).ConfigureAwait(false);
                            }
                        }
                    }
                }
            }
            return result;
        }
        /// <summary>
        /// 驗證校驗碼是否正確
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="code">校驗碼</param>
        /// <param name="maxErrorLimit">最大允許錯誤次數</param>
        /// <returns></returns>
        public async Task<VerificationResult> VerifyCode(string receiver, string bizFlag, string code, int maxErrorLimit)
        {
            var result = VerificationResult.Expired;
            var vCode = await this.Storage.GetEffectiveCode(receiver, bizFlag).ConfigureAwait(false);
            if (vCode != null && !string.IsNullOrWhiteSpace(vCode.Item1))
            {
                result = VerificationResult.MaxErrorLimit;
                if (vCode.Item2 < maxErrorLimit)
                {
                    result = VerificationResult.Success;
                    if (!string.Equals(vCode.Item1, code, StringComparison.OrdinalIgnoreCase))
                    {
                        result = VerificationResult.VerificationFailed;
                        await this.Storage.IncreaseCodeErrors(receiver, bizFlag).ConfigureAwait(false);
                    }
                }
            }
            return result;
        }
        /// <summary>
        /// 獲取由數字組成的校驗碼
        /// </summary>
        /// <param name="maxLength">校驗碼長度</param>
        /// <returns></returns>
        public static string GetRandomNumber(int maxLength = 6)
        {
            if (maxLength <= 0 || maxLength >= 10)
            {
                throw new ArgumentOutOfRangeException($"{nameof(maxLength)} must between {1} and {9}.");
            }
            var rd = Math.Abs(Guid.NewGuid().GetHashCode());
            var tmpX = (int)Math.Pow(10, maxLength);
            return (rd % tmpX).ToString().PadLeft(maxLength, '0');
        }
    }

除了上述標準通用實現，還有一些半通用實現，比如本文標題中的Redis，所謂半通用，就是指你可以直接拿來用，但有可能不符合你的技術場景，此時你需要自己重寫一份。

CodeStorageWithRedisCache，注意該類庫採用了StackExchange.Redis.Extensions.Core，你可以在nuget上下載該類庫，如果你對默認的Redis鍵值生成方式不滿意，你也可以通過重寫GetKey方法來指定新的鍵值生成方式。當然，因爲實際存儲在Redis中的數據都只是一些簡單數據，並不需要額外的序列化過程，實際你也可以直接使用StackExchange.Redis。

    /// <summary>
    /// 校驗碼信息存儲到Redis
    /// </summary>
    public class CodeStorageWithRedisCache : ICodeStorage
    {
        private readonly IRedisCacheClient _client;
        private const string CodeValueHashKey = "Code";
        private const string CodeErrorHashKey = "Error";
        private const string PeriodHashKey = "Period";
        /// <summary>
        /// Code緩存Key值前綴
        /// </summary>
        public string CodeKeyPrefix { get; set; } = "CC";
        /// <summary>
        /// Period緩存Key值前綴
        /// </summary>
        public string PeriodKeyPrefix { get; set; } = "CCT";
        /// <summary>
        /// 緩存寫入Redis哪個庫
        /// </summary>
        public int DbNumber { get; set; } = 8;
        /// <summary>
        /// 基於RedisCacheClient的構造函數
        /// </summary>
        /// <param name="client"></param>
        public CodeStorageWithRedisCache(IRedisCacheClient client)
        {
            this._client = client;
        }
        /// <summary>
        /// 獲取校驗碼週期內已發送次數，如果週期已到或未發送過任何驗證碼，則返回0
        /// </summary>
        /// <param name="receiver"></param>
        /// <param name="bizFlag"></param>
        /// <returns></returns>
        public async Task<int> GetAreadySendTimes(string receiver, string bizFlag)
        {
            var db = this.GetDatabase();
            var key = this.GetPeriodKey(receiver, bizFlag);
            var times = await db.HashGetAsync<int>(key, PeriodHashKey).ConfigureAwait(false);
#if DEBUG
            Console.WriteLine("Method:{0} Result:{1}", nameof(GetAreadySendTimes), times);
#endif
            return times;
        }
        /// <summary>
        /// 獲取校驗碼及已嘗試錯誤次數，如果校驗碼不存在或已過期，則返回null
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <returns></returns>
        public async Task<Tuple<string, int>> GetEffectiveCode(string receiver, string bizFlag)
        {
            var db = this.GetDatabase();
            var key = this.GetCodeKey(receiver, bizFlag);
            if (await db.ExistsAsync(key).ConfigureAwait(false))
            {
                var code = await db.HashGetAsync<string>(key, CodeValueHashKey).ConfigureAwait(false);
                var errors = await db.HashGetAsync<int>(key, CodeErrorHashKey).ConfigureAwait(false);
#if DEBUG
                Console.WriteLine("Method:{0} Result:  Code {1} Errors {2} ", nameof(GetEffectiveCode), code, errors);
#endif
                return Tuple.Create(code, errors);
            }
            return null;
        }
        /// <summary>
        /// 校驗碼錯誤次數+1，如果校驗碼已過期，則不進行任何操作
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <returns></returns>
        public async Task IncreaseCodeErrors(string receiver, string bizFlag)
        {
            var db = this.GetDatabase();
            var key = this.GetCodeKey(receiver, bizFlag);
            if (await db.ExistsAsync(key).ConfigureAwait(false))
            {
                var errors = await db.HashGetAsync<int>(key, CodeErrorHashKey).ConfigureAwait(false);
                await db.HashSetAsync(key, CodeErrorHashKey, errors + 1).ConfigureAwait(false);
            }
        }
        /// <summary>
        /// 校驗碼週期內發送次數+1，如果週期已到，則不進行任何操作
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <returns></returns>
        public async Task IncreaseSendTimes(string receiver, string bizFlag)
        {
            var db = this.GetDatabase();
            var key = this.GetPeriodKey(receiver, bizFlag);
            if (await db.ExistsAsync(key).ConfigureAwait(false))
            {
                var times = await db.HashGetAsync<int>(key, PeriodHashKey).ConfigureAwait(false);
                await db.HashSetAsync(key, PeriodHashKey, times + 1).ConfigureAwait(false);
            }
        }
        /// <summary>
        /// 將校驗碼進行持久化，如果接收方和業務標誌組合已經存在，則進行覆蓋
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="code">校驗碼</param>
        /// <param name="effectiveTime">校驗碼有效時間範圍</param>
        /// <returns></returns>
        public async Task<bool> SetCode(string receiver, string bizFlag, string code, TimeSpan effectiveTime)
        {
            var db = this.GetDatabase();
            var key = this.GetCodeKey(receiver, bizFlag);
            await db.RemoveAsync(key).ConfigureAwait(false);
            var ret = await db.HashSetAsync(key, CodeValueHashKey, code).ConfigureAwait(false)
            && await db.HashSetAsync(key, CodeErrorHashKey, 0).ConfigureAwait(false)
            && await db.UpdateExpiryAsync(key, effectiveTime);
#if DEBUG
            Console.WriteLine("Method:{0} Result:{1}", nameof(SetCode), ret);
#endif
            return ret;
        }
        /// <summary>
        /// 校驗碼發送次數週期持久化，如果接收方和業務標誌組合已經存在，則進行覆蓋
        /// </summary>
        /// <param name="receiver">接收方</param>
        /// <param name="bizFlag">業務標誌</param>
        /// <param name="period">週期時間範圍</param>
        /// <returns></returns>
        public async Task<bool> SetPeriod(string receiver, string bizFlag, TimeSpan? period)
        {
            var db = this.GetDatabase();
            var key = this.GetPeriodKey(receiver, bizFlag);
            await db.RemoveAsync(key).ConfigureAwait(false);
            var ret = await db.HashSetAsync(key, PeriodHashKey, 1).ConfigureAwait(false);
            if (period.HasValue)
            {
                ret = ret && await db.UpdateExpiryAsync(key, period.Value);
            }
#if DEBUG
            Console.WriteLine("Method:{0} Result:{1}", nameof(SetPeriod), ret);
#endif
            return ret;
        }
        /// <summary>
        /// 組織Redis鍵值
        /// </summary>
        /// <param name="receiver"></param>
        /// <param name="bizFlag"></param>
        /// <param name="prefix"></param>
        /// <returns></returns>
        protected virtual string GetKey(string receiver, string bizFlag, string prefix)
        {
            return string.Format("{0}:{1}:{2}", prefix, bizFlag, receiver);
        }
        private string GetPeriodKey(string receiver, string bizFlag)
        {
            return this.GetKey(receiver, bizFlag, this.PeriodKeyPrefix);
        }
        private string GetCodeKey(string receiver, string bizFlag)
        {
            return this.GetKey(receiver, bizFlag, this.CodeKeyPrefix);
        }
        private IRedisDatabase GetDatabase()
        {
            return this._client.GetDb(this.DbNumber);
        }
    }

最後，就是不可能通用的實現了，對於ICodeSender而言，先不說發送方式不同，就算相同，比如都是手機，那也還有不同的短信供應商，所以此處必須要使用者按自己的實際業務來實現，爲了方便舉例，這裏我寫了一個在控制檯輸出驗證碼內容的實現。

ConsoleSender，注意IsSupport在此處輸出true，代表支持任意receiver

    /// <summary>
    /// 在控制檯輸出校驗碼
    /// </summary>
    public class ConsoleSender : ICodeSender
    {
        public ConsoleSender(IContentFormatter formatter)
        {
            this.Formatter = formatter ?? throw new ArgumentNullException(nameof(formatter));
        }
        public IContentFormatter Formatter { get; }

        public bool IsSupport(string receiver) => true;

        public Task<bool> Send(string receiver, string bizFlag, string code, TimeSpan effectiveTime)
        {
            var content = this.Formatter.GetContent(receiver, bizFlag, code, effectiveTime);
            Console.WriteLine("發送內容：{0}", content);
            return Task.FromResult(true);
        }
    }

最後則是如何使用的代碼例子，注意此處Redis序列化方式採用了StackExchange.Redis.Extensions.Newtonsoft，你可以根據實際需要採用其它序列化方式，比如StackExchange.Redis.Extensions.Protobuf等，你同樣可以在nuget上下載到這些類庫。

static void CheckCodeHelperDemo()
{
    var redisConfig = new RedisConfiguration
    {
        Hosts = new RedisHost[] {
            new RedisHost{
                    Host="127.0.0.1",
                    Port=6379
            }
        }
    };
    var bizFlag = "forgetPassword";
    var receiver = "Receiver";
    var effectiveTime = TimeSpan.FromMinutes(1);
    var redisManager = new RedisCacheConnectionPoolManager(redisConfig);
    var redisClient = new RedisCacheClient(redisManager,
        new NewtonsoftSerializer(), redisConfig);//new ProtobufSerializer();
    var storage = new CodeStorageWithRedisCache(redisClient);
    var simpleFormatter = new ContentFormatter(
            (r, b, c, e) => $"{r}您好，您的忘記密碼驗證碼爲{c}，有效期爲{(int)e.TotalSeconds}秒.");
    var formatter = new ComplexContentFormatter();
    formatter.SetFormatter(bizFlag, simpleFormatter);
    var sender = new ConsoleSender(formatter); //如果就一個業務場景，也可以直接用simpleFormatter
    //var tmp = storage.SetPeriod(receiver, bizFlag, TimeSpan.FromMinutes(20)).Result;
    var helper = new CodeHelper(sender, storage);
    var code = CodeHelper.GetRandomNumber();
    var sendResult = helper.SendCode(receiver, bizFlag, code, effectiveTime, new PeriodLimit
    {
        MaxLimit = 5,
        Period = TimeSpan.FromMinutes(20)
    }).Result;
    Console.WriteLine("發送結果：{0}", sendResult);
    if (sendResult == SendResult.Success)
    {
        Console.WriteLine("*****************************");
        while (true)
        {
            Console.WriteLine("請輸入校驗碼：");
            var vCode = Console.ReadLine();
            var vResult = helper.VerifyCode(receiver, bizFlag, vCode, 3).Result;
            Console.WriteLine("校驗碼 {0} 校驗結果：{1}", vCode, vResult);
            if (vResult != VerificationResult.VerificationFailed)
            {
                break;
            }
        }
    }
    redisManager.Dispose();
}

最後則是不同測試場景的一些截圖

驗證碼校驗失敗達到允許次數上限
校驗碼已過期
校驗碼驗證成功
校驗碼週期內允許的發送次數已達到上限

最後，上述完整的代碼可見github。

基於Redis實現的驗證碼發送及校驗方案

記一次 .NET某工業設計軟件崩潰分析

創建 Vue3 項目

TS + Webpack 整合 Jest

分享5款.NET開源免費的Redis客戶端組件庫

安卓手機如何登錄抖音境外版

golang開發 gorilla websocket的使用

面試官：如果不允許線程池丟棄任務，應該選擇哪個拒絕策略？

嵌入式汽車電子學習路線

Mac卸載 Node npm，升級 Node

uni.showModel內容換行

已有MVC項目（非Net Core）如何快速接入Cas單點登錄

蘋果ipa包發佈在IIS環境記錄

【微信卡包發票導入】微信電子發票報銷方服務端接入時遇到的那些坑

如何通過增值稅（區塊鏈）發票上的二維碼獲取發票要素信息

Windows7下安裝docker記錄

https://yachay.unat.edu.pe/blog/index.php?comment_area=format_blog&comment_component=blog&comment_co

linux以太網驅動總結