图形验证码跨平台

src/platform/ZhonTai.Admin/Tools/Captcha/VerifyCodeHelper.cs

@@ -1,7 +1,11 @@
-using System;
-using System.Drawing;
-using System.Drawing.Imaging;
+using SixLabors.Fonts;
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.Drawing.Processing;
+using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Processing;
+using System;
 using System.IO;
+using System.Linq;
 using System.Text;
 using ZhonTai.Admin.Core.Attributes;
 using ZhonTai.Admin.Core.Configs;
@@ -23,7 +27,7 @@ namespace ZhonTai.Admin.Tools.Captcha
             var chars = new StringBuilder();
             //验证码的字符集，去掉了一些容易混淆的字符
             char[] character = { '2', '3', '4', '5', '6', '8', '9', 'a', 'b', 'd', 'e', 'f', 'h', 'k', 'm', 'n', 'r', 'x', 'y', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' };
-            Random rnd = new Random();
+            var rnd = new Random();
             //生成验证码字符串
             for (int i = 0; i < length; i++)
             {
@@ -39,19 +43,18 @@ namespace ZhonTai.Admin.Tools.Captcha
             int fontSize = 22;
 
             //颜色列表，用于验证码、噪线、噪点
-            Color[] color = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue };
+            Color[] colors = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue };
             //字体列表，用于验证码
             string[] fonts = _appConfig.VarifyCode.Fonts;
 
-            code = GenerateRandom(length);
+            var chars = GenerateRandom(length);
+            code = chars;
 
-            //创建画布
-            using (Bitmap bmp = new Bitmap(codeW, codeH))
-            using (Graphics g = Graphics.FromImage(bmp))
-            using (MemoryStream ms = new MemoryStream())
+            using var img = new Image<Rgba32>(codeW, codeH, Color.White);
+
+            img.Mutate(ctx =>
             {
-                g.Clear(Color.White);
-                Random rnd = new Random();
+                var rnd = new Random();
                 //画噪线
                 for (int i = 0; i < 1; i++)
                 {
@@ -59,28 +62,46 @@ namespace ZhonTai.Admin.Tools.Captcha
                     int y1 = rnd.Next(codeH);
                     int x2 = rnd.Next(codeW);
                     int y2 = rnd.Next(codeH);
-                    Color clr = color[rnd.Next(color.Length)];
-                    g.DrawLine(new Pen(clr), x1, y1, x2, y2);
+                    int ctrlx1 = rnd.Next(codeW / 4, codeW / 4 * 3), ctrly1 = rnd.Next(5, codeH - 5);
+                    int ctrlx2 = rnd.Next(codeW / 4, codeW / 4 * 3), ctrly2 = rnd.Next(5, codeH - 5);
+                    Color color = colors[rnd.Next(colors.Length)];
+                    ctx.DrawBeziers(new DrawingOptions
+                    {
+                        GraphicsOptions = new GraphicsOptions
+                        {
+                            BlendPercentage = 1
+                        }
+                    }, color, 1, new PointF(x1, y1), new PointF(ctrlx1, ctrly1), new PointF(ctrlx2, ctrly2), new PointF(x2, y2));
                 }
 
                 //画验证码字符串
                 {
-                    string fnt;
-                    Font ft;
-                    Color clr;
-                    for (int i = 0; i < code.Length; i++)
+                    Color color;
+                    Font font;
+                    string fontName;
+                    FontFamily fontFamily;
+                    for (int i = 0; i < length; i++)
                     {
-                        fnt = fonts[rnd.Next(fonts.Length)];
-                        ft = new Font(fnt, fontSize);
-                        clr = color[rnd.Next(color.Length)];
-                        g.DrawString(code[i].ToString(), ft, new SolidBrush(clr), (float)i * 24 + 2, (float)0);
+                        fontName = fonts[rnd.Next(fonts.Length)];
+                        fontFamily = SystemFonts.Families.Where(a => a.Name == fontName).FirstOrDefault();
+                        fontFamily = fontFamily.Name.NotNull() ? fontFamily : SystemFonts.Families.FirstOrDefault();
+                        font = new Font(fontFamily, fontSize);
+                        color = colors[rnd.Next(colors.Length)];
+                        ctx.DrawText(new DrawingOptions
+                        {
+                            GraphicsOptions = new GraphicsOptions
+                            {
+                                BlendPercentage = 1
+                            }
+                        }, chars[i].ToString(), font, color, new PointF((float)i * 24 + 2, 0));
                     }
                 }
+            });
 
-                //将验证码图片写入内存流，并将其以 "image/Png" 格式输出
-                bmp.Save(ms, ImageFormat.Png);
-                return ms.ToArray();
-            }
+            //将验证码图片写入内存流，并将其以 "image/Png" 格式输出
+            using var ms = new MemoryStream();
+            img.SaveAsPng(ms);
+            return ms.ToArray();
         }
 
         public string GetBase64String(out string code, int length = 4)