计算机专业毕业设计：[21]验证码的制作

1、在网页左侧有一个用户登录的界面，为防止恶意攻击，我们需要用户在登录的时候输入验证码，本节我们就讲述一下如何制作验证码图片

2、代码【<img id="Img1" src="image.aspx" alt="" width ="50px" height ="18px"/>】我们用图片标签，链接一个验证码页面

3、在【new】文件夹上单击右键，选择【新建项】

4、选择【Web窗体】命名为【image.aspx】点击【添加】

5、Web 窗体设计器生成的代码 override protected void O艘绒庳焰nInit(EventArgs e) { // // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。 // InitializeComponent(); base.OnInit(e); } /// <summary> /// 设计器支持所需的方法 - 不要使用代码编辑器修改 /// 此方法的内容。 /// </summary> private void InitializeComponent() { this.Load += new System.EventHandler(this.Page_Load); }

6、生成数字和字母的代码【 private string CreateAuthStr(int len) { int number; StringBuilder code = new StringBuilder(); string checkCode = String.Empty; Random random = new Random(); for (int i = 0; i < len; i++) { number = random.Next(); if (number % 2 == 0) { code.Append((char)('0' + (char)(number % 10))); } else { code.Append((char)('A' + (char)(number % 26))); } } checkCode = code.ToString(); Response.Cookies.Add(new HttpCookie("CheckCode", checkCode)); return checkCode.ToString(); }】

7、为了防止被其他软件识别出验证码，我们需要增加图片的背景噪音线和前景噪音点

8、因为代码比较多，也特别复杂，天使直接附上代码，同学们直接用我的就行了using System;using System.Data;using System.Configuration;using System.Collections;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using System.IO;using System.Drawing;using System.Drawing.Imaging;using System.Text;using System.Text.RegularExpressions;public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { //this.CreateCheckCodeImage(CreateAuthStr(5)); this.CreateCheckCodeImage(CreateAuthStr(5, true)); } #region Web 窗体设计器生成的代码 override protected void OnInit(EventArgs e) { // // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。 // InitializeComponent(); base.OnInit(e); } /// <summary> /// 设计器支持所需的方法 - 不要使用代码编辑器修改 /// 此方法的内容。 /// </summary> private void InitializeComponent() { this.Load += new System.EventHandler(this.Page_Load); } #endregion private string CreateAuthStr(int len) { int number; StringBuilder code = new StringBuilder(); string checkCode = String.Empty; Random random = new Random(); for (int i = 0; i < len; i++) { number = random.Next(); if (number % 2 == 0) { code.Append((char)('0' + (char)(number % 10))); } else { code.Append((char)('A' + (char)(number % 26))); } } checkCode = code.ToString(); Response.Cookies.Add(new HttpCookie("CheckCode", checkCode)); return checkCode.ToString(); } private string CreateAuthStr(int len, bool OnlyNum) { if (!OnlyNum) { return CreateAuthStr(len); } int number; string checkCode = String.Empty; StringBuilder code = new StringBuilder(); Random random = new Random(); for (int i = 0; i < len; i++) { number = random.Next(); code.Append((char)('0' + (char)(number % 10))); } checkCode = code.ToString(); Response.Cookies.Add(new HttpCookie("CheckCode", checkCode)); return checkCode.ToString(); } private void CreateCheckCodeImage(string checkCode) { if (checkCode == null || checkCode.Trim() == String.Empty) return; Bitmap image = new Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22); Graphics g = Graphics.FromImage(image); try { //生成随机生成器 Random random = new Random(); //清空图片背景色 g.Clear(Color.White); //画图片的背景噪音线 for (int i = 0; i < 25; i++) { int x1 = random.Next(image.Width); int x2 = random.Next(image.Width); int y1 = random.Next(image.Height); int y2 = random.Next(image.Height); g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2); } Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic)); System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true); g.DrawString(checkCode, font, brush, 2, 2); //画图片的前景噪音点 for (int i = 0; i < 100; i++) { int x = random.Next(image.Width); int y = random.Next(image.Height); image.SetPixel(x, y, Color.FromArgb(random.Next())); } //画图片的边框线 g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1); System.IO.MemoryStream ms = new System.IO.MemoryStream(); image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif); Response.ClearContent(); Response.ContentType = "image/Gif"; Response.BinaryWrite(ms.ToArray()); } finally { g.Dispose(); image.Dispose(); } } }

9、验证码已经生成，刷新一次自动生成一次