.net 7 验证码功能

using SixLabors.ImageSharp

还需要用到 2 个的插件, SixLabors.Fonts 和 SixLabors.ImageSharp.Drawing
通过CLI手动安装
dotnet add package SixLabors.ImageSharp.Drawing --version 1.0.0-beta15
dotnet add package SixLabors.Fonts --version 1.0.0-beta19

using System.Text;
using NPOI.OpenXmlFormats.Spreadsheet;
using SixLabors.Fonts;
using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Drawing.Processing;
using SixLabors.ImageSharp.Formats.Png;
using SixLabors.ImageSharp.PixelFormats;
using SixLabors.ImageSharp.Processing;
using ZXing;

namespace Cps.WebApi.Core.Wx
{
    /// <summary>
    /// 生成验证码
    /// </summary>
    public class ValidateCode
    {
        private static readonly SixLabors.ImageSharp.Color[] Colors = {
            SixLabors.ImageSharp.Color.Black,
            SixLabors.ImageSharp.Color.Red,
            SixLabors.ImageSharp.Color.Blue,
            SixLabors.ImageSharp.Color.Green,
            SixLabors.ImageSharp.Color.Orange,
            SixLabors.ImageSharp.Color.Brown,
            SixLabors.ImageSharp.Color.Brown,
            SixLabors.ImageSharp.Color.DarkBlue
        };
        private static readonly char[] Chars = { '2', '3', '4', '5', '6', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' };
        //private static readonly int Width = 90;
        //private static readonly int Height = 35;

        /// <summary>
        /// 获取转码
        /// </summary>
        /// <param name="num"></param>
        /// <returns></returns>
        private static string GenCode(int num)
        {
            var code = string.Empty;
            var r = new Random();

            for (int i = 0; i < num; i++)
            {
                code += Chars[r.Next(Chars.Length)].ToString();
            }

            return code;
        }

        /// <summary>
        /// 生成验证码
        /// </summary>
        /// <param name="CodeLength"></param>
        /// <param name="Width"></param>
        /// <param name="Height"></param>
        /// <param name="FontSize"></param>
        /// <returns></returns>
        public static (string code, string base64) CreateValidateGraphic(int CodeLength, int Width, int Height, int FontSize)
        {
            var code = GenCode(CodeLength);
            var r = new Random();
            using var image = new Image<Rgba32>(Width, Height);
            // 字体
            var font = SixLabors.Fonts.SystemFonts.CreateFont(SixLabors.Fonts.SystemFonts.Families.First().Name, FontSize, SixLabors.Fonts.FontStyle.Bold);
            image.Mutate(ctx =>
            {
                // 白底背景
                ctx.BackgroundColor(SixLabors.ImageSharp.Color.White);

                // 画验证码
                for (int i = 0; i < code.Length; i++)
                {
                    ctx.DrawText(code[i].ToString()
                        , font
                        , Colors[r.Next(Colors.Length)]
                        , new PointF(20 * i + 10, r.Next(2, 12)));
                }

                // 画干扰线
                for (int i = 0; i < 6; i++)
                {
                    var pen = new Pen(Colors[r.Next(Colors.Length)], 1);
                    var p1 = new PointF(r.Next(Width), r.Next(Height));
                    var p2 = new PointF(r.Next(Width), r.Next(Height));

                    ctx.DrawLines(pen, p1, p2);
                }

                // 画噪点
                for (int i = 0; i < 60; i++)
                {
                    var pen = new Pen(Colors[r.Next(Colors.Length)], 1);
                    var p1 = new PointF(r.Next(Width), r.Next(Height));
                    var p2 = new PointF(p1.X + 1f, p1.Y + 1f);

                    ctx.DrawLines(pen, p1, p2);
                }
            });
            using var ms = new System.IO.MemoryStream();
            //  格式 自定义
            image.SaveAsPng(ms);
            //image.Save(ms, new PngEncoder());
            byte[] imageBytes = ms.ToArray();
            var base64String = Convert.ToBase64String(imageBytes);
            return (code, "data:image/png;base64," + base64String);
        }
    }
}

调用方法

        /// <summary>
        /// 获取验证码
        /// </summary>
        /// <returns></returns>
        [AllowAnonymous]
        [HttpGet]
        public IActionResult GetValidateGraphic()
        {
            try
            {
                var YzmData = ValidateCode.CreateValidateGraphic(4, 95, 40, 22);
                System.Random random = new System.Random();
                string RandomValue = random.Next(0, 2147483646).ToString();
                CpsCache.SetDatas("LoginYzm_" + RandomValue, YzmData.code, (DateTime.Now.AddMinutes(5) - DateTime.Now));
                var retData = new
                {
                    RandomValue = RandomValue,
                    Img = YzmData.base64
                };
                return Success(retData);
            }
            catch (Exception ex)
            {
                return Fail("操作失败," + ex.Message);
            }
        }