using SkiaSharp;
|
using System;
|
using System.Collections.Generic;
|
using System.Drawing;
|
using System.IO;
|
using System.Linq;
|
using System.Text;
|
using System.Threading.Tasks;
|
|
namespace WIDESEAWCS_Core.Utilities
|
{
|
public static class VierificationCode
|
{
|
private static readonly string[] _chars = new string[] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "P", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" };
|
|
private static readonly SKColor[] colors = { SKColors.Black, SKColors.Green, SKColors.Brown };
|
|
private static readonly string[] fonts = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" };
|
public static string RandomText()
|
{
|
string code = "";//产生的随机数
|
int temp = -1;
|
Random rand = new Random();
|
for (int i = 1; i < 5; i++)
|
{
|
if (temp != -1)
|
{
|
rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks));
|
}
|
int t = rand.Next(61);
|
if (temp != -1 && temp == t)
|
{
|
return RandomText();
|
}
|
temp = t;
|
code += _chars[t];
|
}
|
return code;
|
}
|
public static string CreateBase64Imgage(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)}";
|
}
|
}
|
}
|
