好久没上论坛了，原本这期该来黑马，但是学校的毕设太恶心，所以只好等待下一期。今天心里痒痒，想着来写点东西。写什么好呢，那就从验证码说起吧。

1. <font color="#000"><font face="宋体,">（一）GenerateCode方法：主要是用来产生随机字符串。
   
2. 
   
3.   /// <summary>
   
4.   /// 随机生成字符串
   
5.   /// </summary>
   
6.   /// <param name="number">字符串长度</param>
   
7.   /// <returns></returns>
   
8.   protected string GenerateCode(int number)
   
9.   {
   
10.   string checkCode = string.Empty;
    
11.   string vChar="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,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";
    
12.   string[] vcArray = vChar.Split(',');
    
13. 
    
14.   int temp = -1;//记录上次随机数值，尽量避免产生几个一样的随机数
    
15.   Random rand = new Random();
    
16.   for (int i = 1; i < number+1; i++)
    
17.   {
    
18.   if (temp != -1)
    
19.   {
    
20.   rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks));
    
21.   }
    
22.   int t = rand.Next(vcArray.Length);
    
23.   if (temp != -1 && temp == t)
    
24.   {
    
25.   return GenerateCode(number);
    
26.   }
    
27.   temp = t;
    
28.   checkCode += vcArray[t];
    
29.   }
    
30.   Response.Cookies.Add(new HttpCookie("CheckCode",checkCode));
    
31.    
    
32. （二）将随机生成的字符串转化成验证码图片
    
33. 
    
34.   /// <summary>
    
35.   /// 生成验证码图片
    
36.   /// </summary>
    
37.   /// <param name="checkCode">随机字符串</param>
    
38.   private void CreateCheckImage(string checkCode)
    
39.   {
    
40.   if (checkCode == null || checkCode.Trim() == string.Empty)
    
41.   {
    
42.   return;
    
43.   }
    
44. 
    
45.   System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length*12.5)),22);
    
46.   Graphics g = Graphics.FromImage(image);
    
47.   try
    
48.   {
    
49.   Random radom = new Random();
    
50.   g.Clear(Color.White);
    
51.   for (int i = 0; i < 2; i++)
    
52.   {
    
53.   int x1 = radom.Next(image.Width);
    
54.   int x2 = radom.Next(image.Width);
    
55.   int y1 = radom.Next(image.Height);
    
56.   int y2 = radom.Next(image.Height);
    
57.   g.DrawLine(new Pen(Color.Black), x1, y1, x2, y2);
    
58.   }
    
59.   Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
    
60.   LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
    
61.   g.DrawString(checkCode, font, brush, 2, 2);
    
62. 
    
63.   //画图片的前景噪音点
    
64.   for (int i = 0; i < 50; i++)
    
65.   {
    
66.   int x = radom.Next(image.Width);
    
67.   int y = radom.Next(image.Height);
    
68.   image.SetPixel(x, y, Color.FromArgb(radom.Next()));
    
69.   }
    
70. 
    
71.   //画图片的边框线
    
72.   g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
    
73.   System.IO.MemoryStream ms = new System.IO.MemoryStream();
    
74.   image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
    
75.   Response.ClearContent();
    
76.   Response.ContentType = "image/Gif";
    
77.   Response.BinaryWrite(ms.ToArray());
    
78. 
    
79.   }
    
80.   catch { }
    
81.   finally
    
82.   {
    
83.   g.Dispose();
    
84.   image.Dispose();
    
85.   }
    
86.   }
    
87. 
    
88. 最后在网页中添加一个Image控件，用来显示验证码图片，并将其的ImageUrl属性设置为验证码页面的名称</font></font>

复制代码

好久没上论坛了，原本这期该来黑马，但是学校的毕设太恶心，所以只好等待下一期。今天心里痒痒，想着来写点东西。写什么好呢，那就从验证码说起吧。

1. <font color="#000"><font face="宋体,">（一）GenerateCode方法：主要是用来产生随机字符串。
   
2. 
   
3.   /// <summary>
   
4.   /// 随机生成字符串
   
5.   /// </summary>
   
6.   /// <param name="number">字符串长度</param>
   
7.   /// <returns></returns>
   
8.   protected string GenerateCode(int number)
   
9.   {
   
10.   string checkCode = string.Empty;
    
11.   string vChar="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,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";
    
12.   string[] vcArray = vChar.Split(',');
    
13. 
    
14.   int temp = -1;//记录上次随机数值，尽量避免产生几个一样的随机数
    
15.   Random rand = new Random();
    
16.   for (int i = 1; i < number+1; i++)
    
17.   {
    
18.   if (temp != -1)
    
19.   {
    
20.   rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks));
    
21.   }
    
22.   int t = rand.Next(vcArray.Length);
    
23.   if (temp != -1 && temp == t)
    
24.   {
    
25.   return GenerateCode(number);
    
26.   }
    
27.   temp = t;
    
28.   checkCode += vcArray[t];
    
29.   }
    
30.   Response.Cookies.Add(new HttpCookie("CheckCode",checkCode));
    
31.    
    
32. （二）将随机生成的字符串转化成验证码图片
    
33. 
    
34.   /// <summary>
    
35.   /// 生成验证码图片
    
36.   /// </summary>
    
37.   /// <param name="checkCode">随机字符串</param>
    
38.   private void CreateCheckImage(string checkCode)
    
39.   {
    
40.   if (checkCode == null || checkCode.Trim() == string.Empty)
    
41.   {
    
42.   return;
    
43.   }
    
44. 
    
45.   System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length*12.5)),22);
    
46.   Graphics g = Graphics.FromImage(image);
    
47.   try
    
48.   {
    
49.   Random radom = new Random();
    
50.   g.Clear(Color.White);
    
51.   for (int i = 0; i < 2; i++)
    
52.   {
    
53.   int x1 = radom.Next(image.Width);
    
54.   int x2 = radom.Next(image.Width);
    
55.   int y1 = radom.Next(image.Height);
    
56.   int y2 = radom.Next(image.Height);
    
57.   g.DrawLine(new Pen(Color.Black), x1, y1, x2, y2);
    
58.   }
    
59.   Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
    
60.   LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
    
61.   g.DrawString(checkCode, font, brush, 2, 2);
    
62. 
    
63.   //画图片的前景噪音点
    
64.   for (int i = 0; i < 50; i++)
    
65.   {
    
66.   int x = radom.Next(image.Width);
    
67.   int y = radom.Next(image.Height);
    
68.   image.SetPixel(x, y, Color.FromArgb(radom.Next()));
    
69.   }
    
70. 
    
71.   //画图片的边框线
    
72.   g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
    
73.   System.IO.MemoryStream ms = new System.IO.MemoryStream();
    
74.   image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
    
75.   Response.ClearContent();
    
76.   Response.ContentType = "image/Gif";
    
77.   Response.BinaryWrite(ms.ToArray());
    
78. 
    
79.   }
    
80.   catch { }
    
81.   finally
    
82.   {
    
83.   g.Dispose();
    
84.   image.Dispose();
    
85.   }
    
86.   }
    
87. 
    
88. 最后在网页中添加一个Image控件，用来显示验证码图片，并将其的ImageUrl属性设置为验证码页面的名称</font></font>

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