NET 很简单的一个生成随机验证码封装的一个类

1. using System;
2. using System.Data;
3. using System.Configuration;
4. using System.Web;
5. using System.Web.Security;
6. using System.Web.UI;
7. using System.Web.UI.WebControls;
8. using System.Web.UI.WebControls.WebParts;
9. using System.Web.UI.HtmlControls;
10. using System.Drawing;
12. /// <summary>
13. /// VerifyCode 的摘要说明 产生随机数
14. /// </summary>
15. public class VerifyCode
16. {
17.     public VerifyCode()
18.     {
20.     }
21.     //产生随机字符串
22.     /// <summary>
23.     /// 产生随机数
24.     /// </summary>
25.     /// <param name="num">需要的字符的个数</param>
26.     /// <returns>返回产生的随机数</returns>
27.     public string GenCode(int num)
28.     {
29.         //定义一个数组
30.         string[] source ={"0","1","2","3","4","5","6","7","8","9",
31.                             "A","B","C","D","E","F","G","H","I","J","K","L","M","N",
32.                             "O","P","Q","R","S","T","U","V","W","X","Y","Z"};
33.         //定义一个装数组的字符串
34.         string code = "";
35.         Random rd = new Random();
36.         for (int i = 0; i < num; i++)
37.         {
38.             code += source[rd.Next(0, source.Length)]; 
39.         }
40.         return code;//返回产生的随机数
41.     }
42.     //生成图片
43.     public void GenImg(string code, Page curPage)
44.     {
45.         Bitmap myPalette = new Bitmap(60, 20);//定义一个画板
46.         Graphics gh = Graphics.FromImage(myPalette);//在画板上定义绘图的实例
47.         Rectangle rc = new Rectangle(0, 0, 60, 20);//定义一个矩形
48.         gh.FillRectangle(new SolidBrush(Color.Blue), rc);//填充矩形
49.         gh.DrawString(code, new Font("宋体", 16), new SolidBrush(Color.White), rc);//在矩形内画出字符串
50.         myPalette.Save(curPage.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);//将图片显示出来
51.         curPage.Session["ValidateCode"] = code;//将字符串保存到Session中，以便需要时进行验证
52.         gh.Dispose();//关闭　
53.         myPalette.Dispose();
54.     }
55. }