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MVC 生成验证码

news 2025/7/8 15:38:55

在mvc 出现之前生成验证码思路

在一个html页面上，生成一个验证码，在把这个页面嵌入到需要验证码的页面中。

JS生成验证码

<script type="text/javascript">jQuery(function ($) {/**生成一个随机数**/function randomNum(min, max) {return Math.floor(Math.random() * (max - min) + min);}/**生成一个随机色**/function randomColor(min, max) {var r = randomNum(min, max);var g = randomNum(min, max);var b = randomNum(min, max);return "rgb(" + r + "," + g + "," + b + ")";}var code = drawPic();document.getElementById("changeImg").onclick = function (e) {e.preventDefault();code = drawPic();}/**绘制验证码图片**/function drawPic() {var canvas = document.getElementById("canvas");var width = canvas.width;var height = canvas.height;//获取该canvas的2D绘图环境 var ctx = canvas.getContext('2d');ctx.textBaseline = 'bottom';/**绘制背景色**/ctx.fillStyle = randomColor(180, 240);//颜色若太深可能导致看不清ctx.fillRect(0, 0, width, height);/**绘制文字**/var str = 'ABCEFGHJKLMNPQRSTWXY123456789';var code = "";//生成四个验证码for (var i = 1; i <= 4; i++) {var txt = str[randomNum(0, str.length)];code = code + txt;ctx.fillStyle = randomColor(50, 160);//随机生成字体颜色ctx.font = randomNum(15, 40) + 'px SimHei';//随机生成字体大小var x = 10 + i * 25;var y = randomNum(25, 35);var deg = randomNum(-45, 45);//修改坐标原点和旋转角度ctx.translate(x, y);ctx.rotate(deg * Math.PI / 180);ctx.fillText(txt, 0, 0);//恢复坐标原点和旋转角度ctx.rotate(-deg * Math.PI / 180);ctx.translate(-x, -y);}/**绘制干扰线**/for (var i = 0; i < 3; i++) {ctx.strokeStyle = randomColor(40, 180);ctx.beginPath();ctx.moveTo(randomNum(0, width / 2), randomNum(0, height / 2));ctx.lineTo(randomNum(0, width / 2), randomNum(0, height));ctx.stroke();}/**绘制干扰点**/for (var i = 0; i < 50; i++) {ctx.fillStyle = randomColor(255);ctx.beginPath();ctx.arc(randomNum(0, width), randomNum(0, height), 1, 0, 2 * Math.PI);ctx.fill();}$("#code").val(code);return code;}});</script>

在这里插入图片描述

MVC中验证码

》》》定义一个生成验证码的类

public class VerifyCodeHelper{public static Bitmap CreateVerifyCode(out string code){//建立Bitmap对象，绘图Bitmap bitmap = new Bitmap(200, 60);Graphics graph = Graphics.FromImage(bitmap);graph.FillRectangle(new SolidBrush(Color.White), 0, 0, 200, 60);Font font = new Font(FontFamily.GenericSerif, 48, FontStyle.Bold, GraphicsUnit.Pixel);Random r = new Random();string letters = "ABCDEFGHIJKLMNPQRSTUVWXYZ0123456789";StringBuilder sb = new StringBuilder();//添加随机的五个字母for (int x = 0; x < 5; x++){string letter = letters.Substring(r.Next(0, letters.Length - 1), 1);sb.Append(letter);graph.DrawString(letter, font, new SolidBrush(Color.Black), x * 38, r.Next(0, 15));}code = sb.ToString();//混淆背景Pen linePen = new Pen(new SolidBrush(Color.Black), 2);for (int x = 0; x < 6; x++)graph.DrawLine(linePen, new Point(r.Next(0, 199), r.Next(0, 59)), new Point(r.Next(0, 199), r.Next(0, 59)));return bitmap;}}

》》》》Action

        /// <summary>/// 验证码 FileContentResult/// </summary>/// <returns></returns>[AllowAnonymous]public ActionResult VerifyCode(){string code = "";Bitmap bitmap = VerifyCodeHelper.CreateVerifyCode(out code);   //声明一个内存流      MemoryStream stream = new MemoryStream();//把bitmap存入这个  流中bitmap.Save(stream, ImageFormat.Gif);// Controller中File方法  返回  FileContentResult， // FileContentResult继承FileResult，FileResult又继承    ActionResultreturn File(stream.ToArray(), "image/gif");//返回FileContentResult图片}/// <summary>/// 验证码  直接写入Response/// </summary>[AllowAnonymous]public void Verify(){string code = "";Bitmap bitmap = VerifyCodeHelper.CreateVerifyCode(out code);bitmap.Save(base.Response.OutputStream, ImageFormat.Gif);base.Response.ContentType = "image/gif";}