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iMES.Core/Utilities/VierificationCodeServices.cs

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+using SkiaSharp;
+using System;
+using System.IO;
+using System.Linq;
+
+namespace iMES.Core.Utilities
+{
+    public static class VierificationCodeServices
+    {        //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.Green, SKColors.Brown };
+
+        /// <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.Fill;
+            pen.TextSize = 20;// 0.6f * 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 * 16,
+                    Y = 22// 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, 0);
+                var p2 = new SKPoint(0, 0);
+                var p3 = new SKPoint(0, 0);
+                var p4 = new SKPoint(0, 0);
+
+                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)}";
+        }
+    }
+}