调整生成验证码的代码以支持linux

Author: 3ddbz

.Net6版本/VOL.Core/Utilities/VierificationCode.cs

@@ -3,6 +3,7 @@
 using System.Drawing;
 using System.Drawing.Imaging;
 using System.IO;
+using System.Runtime.Versioning;
 using System.Text;
 
 namespace VOL.Core.Utilities
@@ -31,6 +32,9 @@ public static string RandomText()
             }
             return code;
         }
+
+        [SupportedOSPlatform("Windows")]
+        [Obsolete("仅在 Windows 上支持 System.Drawing.Common,具体请参考：https://docs.microsoft.com/zh-cn/dotnet/core/compatibility/core-libraries/6.0/system-drawing-common-windows-only")]
         public static string CreateBase64Imgage(string code)
         {
             Random random = new Random();

.Net6版本/VOL.Core/Utilities/VierificationCodeHelpers.cs

@@ -0,0 +1,97 @@
+using System;
+using System.IO;
+using System.Linq;
+using SkiaSharp;
+
+namespace VOL.Core.Utilities;
+
+public static class VierificationCodeHelpers
+{        //验证码字体集合
+    private static readonly string[] fonts = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" };
+    private static readonly SKColor[] colors = { SKColors.Black, SKColors.Red, SKColors.DarkBlue, SKColors.Green,
+        SKColors.Orange, SKColors.Brown, SKColors.DarkCyan, SKColors.Purple};
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="code"></param>
+    /// <returns></returns>
+    public static string CreateBase64Image(string code)
+    {
+        var random = new Random();
+        var info = new SKImageInfo((int)code.Length * 18, 32);
+        using var bitmap = new SKBitmap(info);
+        using var canvas = new SKCanvas(bitmap);
+
+        canvas.Clear(SKColors.White);
+
+        using var pen = new SKPaint();
+        pen.FakeBoldText = true;
+        pen.Style = SKPaintStyle.Stroke;
+        pen.TextSize = 0.9f * info.Width * pen.TextSize / pen.MeasureText(code);
+
+        //绘制随机字符
+        for (int i = 0; i < code.Length; i++)
+        {
+            pen.Color = random.GetRandom(colors);//随机颜色索引值
+            pen.Typeface = SKTypeface.FromFamilyName(random.GetRandom(fonts), 700, 20, SKFontStyleSlant.Italic);//配置字体
+            var point = new SKPoint()
+            {
+                X = i * 12,
+                Y = info.Height - ((i + 1) % 2 == 0 ? 2 : 4)
+            };
+            canvas.DrawText(code.Substring(i, 1), point, pen);//绘制一个验证字符
+        }
+
+        //绘制噪点
+        var points = Enumerable.Range(0, 100).Select(
+            _ => new SKPoint(random.Next(bitmap.Width), random.Next(bitmap.Height))
+        ).ToArray();
+        canvas.DrawPoints(
+            SKPointMode.Points,
+            points,
+            pen);
+
+        //绘制贝塞尔线条
+        for (int i = 0; i < 2; i++)
+        {
+            var p1 = new SKPoint(0, random.Next(bitmap.Height));
+            var p2 = new SKPoint(random.Next(bitmap.Width), random.Next(bitmap.Height));
+            var p3 = new SKPoint(random.Next(bitmap.Width), random.Next(bitmap.Height));
+            var p4 = new SKPoint(bitmap.Width, random.Next(bitmap.Height));
+
+            var touchPoints = new SKPoint[] { p1, p2, p3, p4 };
+
+            using var bPen = new SKPaint();
+            bPen.Color = random.GetRandom(colors);
+            bPen.Style = SKPaintStyle.Stroke;
+
+            using var path = new SKPath();
+            path.MoveTo(touchPoints[0]);
+            path.CubicTo(touchPoints[1], touchPoints[2], touchPoints[3]);
+            canvas.DrawPath(path, bPen);
+        }
+        return bitmap.ToBase64String(SKEncodedImageFormat.Png);
+    }
+
+    public static T GetRandom<T>(this Random random, T[] tArray)
+    {
+        if (random == null) random = new Random();
+        return tArray[random.Next(tArray.Length)];
+    }
+
+    /// <summary>
+    /// SKBitmap转Base64String
+    /// </summary>
+    /// <param name="bitmap"></param>
+    /// <param name="format"></param>
+    /// <returns></returns>
+    public static string ToBase64String(this SKBitmap bitmap, SKEncodedImageFormat format)
+    {
+        using var memStream = new MemoryStream();
+        using var wstream = new SKManagedWStream(memStream);
+        bitmap.Encode(wstream, format, 32);
+        memStream.TryGetBuffer(out ArraySegment<byte> buffer);
+        return $"{Convert.ToBase64String(buffer.Array, 0, (int)memStream.Length)}";
+    }
+}

.Net6版本/VOL.Core/VOL.Core.csproj

@@ -54,6 +54,7 @@
     <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="6.0.0" />
     <!--<PackageReference Include="MySql.Data" Version="8.0.13" />-->
     <PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="6.0.0" />
+    <PackageReference Include="SkiaSharp.NativeAssets.Linux" Version="2.88.0" />
     <PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="6.17.0" />
     <PackageReference Include="ZKWeb.System.Drawing" Version="4.0.1" />
   </ItemGroup>

.Net6版本/VOL.WebApi/Controllers/System/Partial/Sys_UserController.cs

@@ -169,7 +169,7 @@ public IActionResult GetVierificationCode()
             string code = VierificationCode.RandomText();
             var data = new
             {
-                img = VierificationCode.CreateBase64Imgage(code),
+                img = VierificationCodeHelpers.CreateBase64Image(code),
                 uuid = Guid.NewGuid()
             };
             HttpContext.GetService<IMemoryCache>().Set(data.uuid.ToString(), code, new TimeSpan(0, 5, 0));