.NET Core 2.0如何生成图片验证码完整实例

using System;using System.DrawingCore;using System.DrawingCore.Drawing2D;using System.DrawingCore.Imaging;using System.IO; namespace Common.Helper{ public sealed class VerifyCodeHelper {  #region 单例模式  //创建私有化静态obj锁   private static readonly object _ObjLock = new object();  //创建私有静态字段，接收类的实例化对象   private static VerifyCodeHelper _VerifyCodeHelper = null;  //构造函数私有化   private VerifyCodeHelper() { }  //创建单利对象资源并返回   public static VerifyCodeHelper GetSingleObj()  {   if (_VerifyCodeHelper == null)   {    lock (_ObjLock)    {     if (_VerifyCodeHelper == null)      _VerifyCodeHelper = new VerifyCodeHelper();    }   }   return _VerifyCodeHelper;  }  #endregion   #region 生产验证码  public enum VerifyCodeType { NumberVerifyCode, AbcVerifyCode, MixVerifyCode };   /// <summary>  /// 1.数字验证码  /// </summary>  /// <param name="length"></param>  /// <returns></returns>  private string CreateNumberVerifyCode(int length)  {   int[] randMembers = new int[length];   int[] validateNums = new int[length];   string validateNumberStr = "";   //生成起始序列值    int seekSeek = unchecked((int)DateTime.Now.Ticks);   Random seekRand = new Random(seekSeek);   int beginSeek = seekRand.Next(0, Int32.MaxValue - length * 10000);   int[] seeks = new int[length];   for (int i = 0; i < length; i++)   {    beginSeek += 10000;    seeks[i] = beginSeek;   }   //生成随机数字    for (int i = 0; i < length; i++)   {    Random rand = new Random(seeks[i]);    int pownum = 1 * (int)Math.Pow(10, length);    randMembers[i] = rand.Next(pownum, Int32.MaxValue);   }   //抽取随机数字    for (int i = 0; i < length; i++)   {    string numStr = randMembers[i].ToString();    int numLength = numStr.Length;    Random rand = new Random();    int numPosition = rand.Next(0, numLength - 1);    validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));   }   //生成验证码    for (int i = 0; i < length; i++)   {    validateNumberStr += validateNums[i].ToString();   }   return validateNumberStr;  }   /// <summary>  /// 2.字母验证码  /// </summary>  /// <param name="length">字符长度</param>  /// <returns>验证码字符</returns>  private string CreateAbcVerifyCode(int length)  {   char[] verification = new char[length];   char[] dictionary = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', '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', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'   };   Random random = new Random();   for (int i = 0; i < length; i++)   {    verification[i] = dictionary[random.Next(dictionary.Length - 1)];   }   return new string(verification);  }   /// <summary>  /// 3.混合验证码  /// </summary>  /// <param name="length">字符长度</param>  /// <returns>验证码字符</returns>  private string CreateMixVerifyCode(int length)  {   char[] verification = new char[length];   char[] dictionary = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',    'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'   };   Random random = new Random();   for (int i = 0; i < length; i++)   {    verification[i] = dictionary[random.Next(dictionary.Length - 1)];   }   return new string(verification);  }   /// <summary>  /// 产生验证码（随机产生4-6位）  /// </summary>  /// <param name="type">验证码类型：数字，字符，符合</param>  /// <returns></returns>  public string CreateVerifyCode(VerifyCodeType type)  {   string verifyCode = string.Empty;   Random random = new Random();   int length = random.Next(4, 6);   switch (type)   {    case VerifyCodeType.NumberVerifyCode:     verifyCode = GetSingleObj().CreateNumberVerifyCode(length);     break;    case VerifyCodeType.AbcVerifyCode:     verifyCode = GetSingleObj().CreateAbcVerifyCode(length);     break;    case VerifyCodeType.MixVerifyCode:     verifyCode = GetSingleObj().CreateMixVerifyCode(length);     break;   }   return verifyCode;  }  #endregion   #region 验证码图片  /// <summary>  /// 验证码图片 => Bitmap  /// </summary>  /// <param name="verifyCode">验证码</param>  /// <param name="width">宽</param>  /// <param name="height">高</param>  /// <returns>Bitmap</returns>  public Bitmap CreateBitmapByImgVerifyCode(string verifyCode, int width, int height)  {   Font font = new Font("Arial", 14, (FontStyle.Bold | FontStyle.Italic));   Brush brush;   Bitmap bitmap = new Bitmap(width, height);   Graphics g = Graphics.FromImage(bitmap);   SizeF totalSizeF = g.MeasureString(verifyCode, font);   SizeF curCharSizeF;   PointF startPointF = new PointF(0, (height - totalSizeF.Height) / 2);   Random random = new Random(); //随机数产生器   g.Clear(Color.White); //清空图片背景色    for (int i = 0; i < verifyCode.Length; i++)   {    brush = new LinearGradientBrush(new Point(0, 0), new Point(1, 1), Color.FromArgb(random.Next(255), random.Next(255), random.Next(255)), Color.FromArgb(random.Next(255), random.Next(255), random.Next(255)));    g.DrawString(verifyCode[i].ToString(), font, brush, startPointF);    curCharSizeF = g.MeasureString(verifyCode[i].ToString(), font);    startPointF.X += curCharSizeF.Width;   }    //画图片的干扰线    for (int i = 0; i < 10; i++)   {    int x1 = random.Next(bitmap.Width);    int x2 = random.Next(bitmap.Width);    int y1 = random.Next(bitmap.Height);    int y2 = random.Next(bitmap.Height);    g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);   }    //画图片的前景干扰点    for (int i = 0; i < 100; i++)   {    int x = random.Next(bitmap.Width);    int y = random.Next(bitmap.Height);    bitmap.SetPixel(x, y, Color.FromArgb(random.Next()));   }    g.DrawRectangle(new Pen(Color.Silver), 0, 0, bitmap.Width - 1, bitmap.Height - 1); //画图片的边框线    g.Dispose();   return bitmap;  }   /// <summary>  /// 验证码图片 => byte[]  /// </summary>  /// <param name="verifyCode">验证码</param>  /// <param name="width">宽</param>  /// <param name="height">高</param>  /// <returns>byte[]</returns>  public byte[] CreateByteByImgVerifyCode(string verifyCode, int width, int height)  {   Font font = new Font("Arial", 14, (FontStyle.Bold | FontStyle.Italic));   Brush brush;   Bitmap bitmap = new Bitmap(width, height);   Graphics g = Graphics.FromImage(bitmap);   SizeF totalSizeF = g.MeasureString(verifyCode, font);   SizeF curCharSizeF;   PointF startPointF = new PointF(0, (height - totalSizeF.Height) / 2);   Random random = new Random(); //随机数产生器   g.Clear(Color.White); //清空图片背景色    for (int i = 0; i < verifyCode.Length; i++)   {    brush = new LinearGradientBrush(new Point(0, 0), new Point(1, 1), Color.FromArgb(random.Next(255), random.Next(255), random.Next(255)), Color.FromArgb(random.Next(255), random.Next(255), random.Next(255)));    g.DrawString(verifyCode[i].ToString(), font, brush, startPointF);    curCharSizeF = g.MeasureString(verifyCode[i].ToString(), font);    startPointF.X += curCharSizeF.Width;   }    //画图片的干扰线    for (int i = 0; i < 10; i++)   {    int x1 = random.Next(bitmap.Width);    int x2 = random.Next(bitmap.Width);    int y1 = random.Next(bitmap.Height);    int y2 = random.Next(bitmap.Height);    g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);   }    //画图片的前景干扰点    for (int i = 0; i < 100; i++)   {    int x = random.Next(bitmap.Width);    int y = random.Next(bitmap.Height);    bitmap.SetPixel(x, y, Color.FromArgb(random.Next()));   }    g.DrawRectangle(new Pen(Color.Silver), 0, 0, bitmap.Width - 1, bitmap.Height - 1); //画图片的边框线    g.Dispose();    //保存图片数据    MemoryStream stream = new MemoryStream();   bitmap.Save(stream, ImageFormat.Jpeg);   //输出图片流    return stream.ToArray();   }  #endregion }}

using System.DrawingCore.Imaging;using System.IO;using Common.Helper;using Microsoft.AspNetCore.Mvc; namespace WebApplicationApi.Controllers{ public class VerifyCodeController : Controller {  public IActionResult Index()  {   return View();  }   /// <summary>  /// 数字验证码  /// </summary>  /// <returns></returns>  public FileContentResult NumberVerifyCode()  {   string code = VerifyCodeHelper.GetSingleObj().CreateVerifyCode(VerifyCodeHelper.VerifyCodeType.NumberVerifyCode);   byte[] codeImage = VerifyCodeHelper.GetSingleObj().CreateByteByImgVerifyCode(code, 100, 40);   return File(codeImage, @"image/jpeg");  }   /// <summary>  /// 字母验证码  /// </summary>  /// <returns></returns>  public FileContentResult AbcVerifyCode()  {   string code = VerifyCodeHelper.GetSingleObj().CreateVerifyCode(VerifyCodeHelper.VerifyCodeType.AbcVerifyCode);   var bitmap = VerifyCodeHelper.GetSingleObj().CreateBitmapByImgVerifyCode(code, 100, 40);   MemoryStream stream = new MemoryStream();   bitmap.Save(stream, ImageFormat.Png);   return File(stream.ToArray(), "image/png");  }   /// <summary>  /// 混合验证码  /// </summary>  /// <returns></returns>  public FileContentResult MixVerifyCode()  {   string code = VerifyCodeHelper.GetSingleObj().CreateVerifyCode(VerifyCodeHelper.VerifyCodeType.MixVerifyCode);   var bitmap = VerifyCodeHelper.GetSingleObj().CreateBitmapByImgVerifyCode(code, 100, 40);   MemoryStream stream = new MemoryStream();   bitmap.Save(stream, ImageFormat.Gif);   return File(stream.ToArray(), "image/gif");  }  }}

@{ Layout = null;}<!DOCTYPE html><html><head> <meta name="viewport" content="width=device-width" /> <title>Index</title></head><body> <figure>  <h3>图片验证码</h3>  <fieldset>   <legend>数字验证码</legend>   <img id="nubImg" title="数字验证码" src="/VerifyCode/NumberVerifyCode?random=" alt="vcode" onclick="refresh()" style="cursor:pointer;" />  </fieldset>  <fieldset>   <legend>数字验证码</legend>   <img id="abcImg" title="字母验证码" src="/VerifyCode/AbcVerifyCode" alt="vcode" onclick="this.src=this.src+'?'" style="cursor:pointer;" />  </fieldset>  <fieldset>   <legend>混合验证码</legend>   <img id="mixImg" title="数字字母混合验证码" src="/VerifyCode/MixVerifyCode" alt="vcode" onclick="this.src=this.src+'?'" style="cursor:pointer;" />  </fieldset> </figure>  <script type="text/javascript">  function refresh() {   var id = document.getElementById("nubImg");   var str = "/VerifyCode/NumberVerifyCode?random=" + Math.random();   id.setAttribute("src", str);  } </script> </body></html>