(给DotNet加星标，提升.Net技能)

转自：殷慈航cnblogs.com/jiyuwu/p/11803979.html

很多人写的博客大家看了会一知半解，不知道怎么用，应该引用什么类库或者代码不全，这样很多小白很是头疼，尤其是尝新技术更是如此。我们这边不止告诉你步骤，而且还提供开源demo。

随着时间的推移，我们的demo库会日益强大请及时收藏

GitHub：https://github.com/jiyuwu/TemplateCore

一、首先你需要Nuget引用类库

Install-Package ZKWeb.System.Drawing -Version 4.0.1

二、创建公共类VerifyCodeHelper和CommonHelper

1、CommonHelper中添加图形处理方法

#region 验证码public static byte[] Bitmap2Byte(Bitmap bitmap){using (MemoryStream stream = new MemoryStream())    {        bitmap.Save(stream, ImageFormat.Jpeg);byte[] data = new byte[stream.Length];        stream.Seek(0, SeekOrigin.Begin);        stream.Read(data, 0, Convert.ToInt32(stream.Length));return data;    }}#endregionpublic static string CodeJson(string code, string msg){return "{\"code\":\"" + code + "\",\"msg\":\"" + msg + "\"}";}

2、VerifyCodeHelper添加图形处理方法

public  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 };

/// /// 1.数字验证码/// /// /// 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;    }/// /// 2.字母验证码/// /// 字符长度/// 验证码字符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);    }/// /// 3.混合验证码/// /// 字符长度/// 验证码字符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);    }/// /// 产生验证码(随机产生4-6位)/// /// 验证码类型：数字，字符，符合/// 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/// /// 验证码图片 => Bitmap/// /// 验证码/// 宽/// 高/// Bitmappublic 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;    }/// /// 验证码图片 => byte[]/// /// 验证码/// 宽/// 高/// byte[]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

三、后台控制器根据请求返回相应图形数据

#region 验证码#region 混合验证码[HttpGet]public string MixVerifyCodeJson(){string code = VerifyCodeHelper.GetSingleObj().CreateVerifyCode(VerifyCodeHelper.VerifyCodeType.MixVerifyCode);var bitmap = VerifyCodeHelper.GetSingleObj().CreateBitmapByImgVerifyCode(code, 100, 40);byte[] imgBt = CommonHelper.Bitmap2Byte(bitmap);string uuid = Guid.NewGuid().ToString();return CommonHelper.CodeJson(uuid, Convert.ToBase64String(imgBt));}[HttpGet]public IActionResult 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.Png);return File(stream.ToArray(), "image/png");}#endregion

#region 数字验证码[HttpGet]public string NumberVerifyCodeJson(){string code = VerifyCodeHelper.GetSingleObj().CreateVerifyCode(VerifyCodeHelper.VerifyCodeType.NumberVerifyCode);var bitmap = VerifyCodeHelper.GetSingleObj().CreateBitmapByImgVerifyCode(code, 100, 40);byte[] imgBt = CommonHelper.Bitmap2Byte(bitmap);string uuid = Guid.NewGuid().ToString();return CommonHelper.CodeJson(uuid, Convert.ToBase64String(imgBt));}[HttpGet]public IActionResult NumberVerifyCode(){string code = VerifyCodeHelper.GetSingleObj().CreateVerifyCode(VerifyCodeHelper.VerifyCodeType.NumberVerifyCode);var bitmap = VerifyCodeHelper.GetSingleObj().CreateBitmapByImgVerifyCode(code, 100, 40);    MemoryStream stream = new MemoryStream();    bitmap.Save(stream, ImageFormat.Png);return File(stream.ToArray(), "image/png");}#endregion

#region 字母验证码[HttpGet]public IActionResult 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");}[HttpGet]public string AbcVerifyCodeJson(){string code = VerifyCodeHelper.GetSingleObj().CreateVerifyCode(VerifyCodeHelper.VerifyCodeType.AbcVerifyCode);var bitmap = VerifyCodeHelper.GetSingleObj().CreateBitmapByImgVerifyCode(code, 100, 40);byte[] imgBt = CommonHelper.Bitmap2Byte(bitmap);string uuid = Guid.NewGuid().ToString();return CommonHelper.CodeJson(uuid, Convert.ToBase64String(imgBt));}#endregion#endregion

四、前端请求分为直接请求文件或json图形数据并渲染至Img标签

<script type="text/javascript">$(function () {    refreshNumJson();    refreshMixJson();    refreshAbcJson();});function refreshNum() {var id = document.getElementById("numImg");var str = "/Verify/NumberVerifyCode?random=" + Math.random();    id.setAttribute("src", str);}function refreshNumJson() {    $.ajax({type: "get",contentType: 'application/json',url: '/Verify/NumberVerifyCodeJson?' + Math.random(),dataType: 'json',async: false,success: function (data) {            $("#numImgJson").attr("src", "data:image/png;base64," + data.msg);console.log(data.code);        },error: function (xhr) {console.log(xhr.responseText);        }    });}function refreshMix() {var id = document.getElementById("mixImg");var str = "/Verify/MixVerifyCode?random=" + Math.random();    id.setAttribute("src", str);}function refreshMixJson() {    $.ajax({type: "get",contentType: 'application/json',url: '/Verify/MixVerifyCodeJson?' + Math.random(),dataType: 'json',async: false,success: function (data) {            $("#mixImgJson").attr("src", "data:image/png;base64," + data.msg);console.log(data.code);        },error: function (xhr) {console.log(xhr.responseText);        }    });}function refreshAbc() {var id = document.getElementById("abcImg");var str = "/Verify/AbcVerifyCode?random=" + Math.random();    id.setAttribute("src", str);}function refreshAbcJson() {    $.ajax({type: "get",contentType: 'application/json',url: '/Verify/AbcVerifyCodeJson?' + Math.random(),dataType: 'json',async: false,success: function (data) {            $("#abcImgJson").attr("src", "data:image/png;base64," + data.msg);console.log(data.code);        },error: function (xhr) {console.log(xhr.responseText);        }    });}script>

<h2>图形数字验证码h2><img id="numImgJson" title="数字验证码Json获取"alt="vcode" style="cursor:pointer;" onclick="refreshNumJson()" />

<a href="javascript:void(0);" onclick="refreshNumJson()">看不清，换一张a><img id="numImg" title="数字验证码" src="/Verify/NumberVerifyCode?random=1994"alt="vcode" style="cursor:pointer;" onclick="refreshNum()" /><a href="javascript:void(0);" onclick="refreshNum()">看不清，换一张a><h2>图形字母验证码h2><img id="abcImgJson" title="图形字母验证码Json获取"alt="vcode" style="cursor:pointer;" onclick="refreshAbcJson()" /><a href="javascript:void(0);" onclick="refreshAbcJson()">看不清，换一张a><img id="abcImg" title="图形字母验证码" src="/Verify/AbcVerifyCode?random=1994"alt="vcode" style="cursor:pointer;" onclick="refreshAbc()" /><a href="javascript:void(0);" onclick="refreshAbc()">看不清，换一张a><h2>图形混合验证码h2><img id="mixImgJson" title="图形混合验证码Json获取"alt="vcode" style="cursor:pointer;" onclick="refreshMixJson()" /><a href="javascript:void(0);" onclick="refreshMixJson()">看不清，换一张a><img id="mixImg" title="图形混合验证码" src="/Verify/MixVerifyCode?random=1994"alt="vcode" style="cursor:pointer;" onclick="refreshMix()" /><a href="javascript:void(0);" onclick="refreshMix()">看不清，换一张a>

五、效果如图

注意：我们机遇屋该项目将长期为大家提供ASP.NET Core各种好用demo，旨在帮助.NET开发者提升竞争力和开发速度，建议尽早收藏该模板集合项目。

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