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  • .Net core api ---- 图形验证码(使用七牛云存储验证码图片)

    代码是以前项目中的  后来移植到core的上面

    以下是代码(封装的类):

     public class ValidateCode
        {
            private string code;
            private const int ImageHeigth = 22;             //验证码图片的高度
            private const double ImageLengthBase = 13;    //验证码图片中每个字符的宽度
            private const int ImageLineNumber = 10;         //噪音线的数量
            private const int ImagePointNumber = 50;       //噪点的数量
            private int length;
            public string key;      //此处用来保存验证码到Session的Key的
            private string url = "/imagecode/";
    
    
            //设置验证码的长度和内容
            public ValidateCode()
            {
                this.length = 4;
                this.code = string.Empty;
            }
    
            ///<summary>
            ///产生随机的验证码并加入缓存
            ///</summary>
            /// <param name = "length" > 验证码长度 </ param >
            ///< returns ></ returns >
            public string CreateCode(int length)
            {
                if (length <= 0)
                {
                    return string.Empty;
                }
                Random random = new Random();
                StringBuilder builder = new StringBuilder();
                //产生随机的验证码并拼接起来
                for (int i = 0; i < length; i++)
                {
                    builder.Append(random.Next(0, 10));
                }
                this.code = builder.ToString();
                // MCachedHelper.Set<string>(key, code, DateTime.Now.AddMinutes(2));
                RedisHelper.StringSet(key, code, 2, RedisFolderEnum.code, RedisEnum.Four);
                return this.code;
            }
            //图形码的内容 可以自定义字母什么的
            private static char[] constant =
           {
            '0','1','2','3','4','5','6','7','8','9'
          };
    
            /// <summary>
            /// Creates the code.
            /// </summary>
            public string CreateCode()
            {
                Random random = new Random();
                StringBuilder builder = new StringBuilder();
    
                for (int i = 0; i < 4; i++) //i<6 生成的就是六位的
                {
                    builder.Append(constant[random.Next(0, 10)]);
                }
                this.code = builder.ToString();
                 //将图形码的内容存储在redis中  验证是取就可以
                RedisHelper.StringSet(key, code, 2, RedisFolderEnum.code, RedisEnum.Four);
                return builder.ToString();
    
            }
    
            /// <summary>
            /// 根据长度产生验证码 , 并将验证码画成图片
            /// </summary>
            /// <param name="length">Length.</param>
            public void CreateValidateImage(int length)
            {
                this.CreateCode();
                this.CreateValidateImage(this.code);
            }
    
            /// <summary>
            /// 将验证码存储在七牛云上
            /// </summary>
            /// <param name="localFile"></param>
            /// <param name="saveKey"></param>
            public static void UploadFile(string localFile, string saveKey)
            {
                #region
                Mac mac = new Mac("", "");//七牛云ak
                // 上传策略,参见 
                // https://developer.qiniu.com/kodo/manual/put-policy
                PutPolicy putPolicy = new PutPolicy();
                // 如果需要设置为"覆盖"上传(如果云端已有同名文件则覆盖),请使用 SCOPE = "BUCKET:KEY"
                // putPolicy.Scope = bucket + ":" + saveKey;  
                putPolicy.Scope = "img-s-code";
                // 上传策略有效期(对应于生成的凭证的有效期)          
                putPolicy.SetExpires(3600);
                // 上传到云端多少天后自动删除该文件,如果不设置(即保持默认默认)则不删除
                putPolicy.DeleteAfterDays = 1;
                string jstr = putPolicy.ToJsonString();
                //获取上传凭证
                var uploadToken = Auth.CreateUploadToken(mac, jstr);
                Qiniu.Common.Config.AutoZone("", "img-s-code", false);//七牛云ak 详情看我的七牛云图片上传
                FormUploader upLoader = new FormUploader(false);
                HttpResult result = upLoader.UploadFile(localFile, saveKey, uploadToken);
                #endregion
    
                if (result.Code != 200)
                {
                    throw new Exception(result.RefText);
                }
                return;
            }
    
            /// <summary>
            ///  根据产生的验证码生成图片
            /// </summary>
            /// <param name="code">Code.</param>
            public void CreateValidateImage(string code)
            {
                if (!string.IsNullOrEmpty(code))
                {
                    //this.Session[key] = code;
                    //初始化位图Bitmap对象,指定图片对象的大小(宽,高)
                    Bitmap image = new Bitmap((int)Math.Ceiling((double)(code.Length * ImageLengthBase)), ImageHeigth);
                    //初始化一块画布
                    Graphics graphics = Graphics.FromImage(image);
                    Random random = new Random();
                    try
                    {
                        int num5;
                        graphics.Clear(Color.White);
                        //绘制噪音线
                        for (num5 = 0; num5 < ImageLineNumber; num5++)
                        {
                            int num = random.Next(image.Width);
                            int num3 = random.Next(image.Height);
                            int num2 = random.Next(image.Width);
                            int num4 = random.Next(image.Height);
                            graphics.DrawLine(new Pen(Color.Silver), num, num3, num2, num4);
                        }
                        //验证码字体样式
                        Font font = new Font("Tahoma", 10, FontStyle.Italic | FontStyle.Bold);
                        LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
                        //绘制验证码到画布
                        graphics.DrawString(code, font, brush, (float)3, (float)2);
                        //绘制噪点
                        for (num5 = 0; num5 < ImagePointNumber; num5++)
                        {
                            int x = random.Next(image.Width);
                            int y = random.Next(image.Height);
                            image.SetPixel(x, y, Color.FromArgb(random.Next()));
                        }
                        graphics.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
    
                        //保存图片
                        if (!Directory.Exists(url))
                        {
                            Directory.CreateDirectory(url);//如果文件夹不存在就创建它
                        }
                        image.Save(url + key + ".gif", ImageFormat.Gif);
    
                        UploadFile(url + key + ".gif", key + ".gif");
                    }
                    finally
                    {
                        graphics.Dispose();
                        image.Dispose();
                    }
    
                }
    
            }
    
            //Properties
            public string Code { get; set; }
    
            public int Length
            {
                get
                {
                    return this.length;
                }
                set
                {
                    this.length = value;
                }
            }
        }
    

      下面是使用方法:

     validatecode.key = Guid.NewGuid().ToString();
                    validatecode.CreateValidateImage(4);
                    validate = new ValidateCodeView
                    {
                        name = validatecode.key, 返回的key
                        imgUrl = $"{_validate.Url}{validatecode.key}.gif" 返回的验证码图片
                    };
    

      验证方法:

    比对输入的值==redis存储的值  

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  • 原文地址:https://www.cnblogs.com/wuyabaibsd/p/11098391.html
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