c#_生成圖片式驗證碼

廢話很少說直接上代碼。

 1     class Check_Code
 2     {
 3         /// <summary>
 4         /// 生成隨機驗證碼數字+字母
 5         /// </summary>
 6         /// <param name="codelen">驗證碼長度</param>
 7         /// <returns>返回驗證碼</returns>
 8         public static string MakeCode(int codelen)
 9         {
10             if (codelen < 1)
11             {
12                 return string.Empty;
13             }
14             int number;
15             StringBuilder strCheckCode = new StringBuilder();
16             Random random = new Random();
17             for (int index = 0; index < codelen; index++)
18             {
19                 number = random.Next();
20                 if (number % 2 == 0)
21                 {
22                     strCheckCode.Append((char)('0' + (char)(number % 10)));//生成隨機數字
23                 }
24                 else
25                 {
26                     strCheckCode.Append((char)('A' + (char)(number % 26)));//生成隨機字母
27                 }
28             }
29             return strCheckCode.ToString();
30         }
31         public static MemoryStream CheckCodeImage(string CheckCode)
32         {
33             if (string.IsNullOrEmpty(CheckCode))
34             {
35                 return null;
36             }
37             Bitmap image = new Bitmap((int)Math.Ceiling((CheckCode.Length * 12.5)), 22);
38             Graphics graphic = Graphics.FromImage(image);//建立一個驗證碼圖片
39             try
40             {
41                 Random random = new Random();
42                 graphic.Clear(Color.White);
43                 int x1 = 0, y1 = 0, x2 = 0, y2 = 0;
44                 for (int index = 0; index < 25; index++)
45                 {
46                     x1 = random.Next(image.Width);
47                     x2 = random.Next(image.Width);
48                     y1 = random.Next(image.Height);
49                     y2 = random.Next(image.Height);
50                     graphic.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
51                 }
52                 Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));//Font設置字體，字號，字形
53                 //設置圖形漸變色的起始顏色與終止顏色，漸變角度
54                 LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Red, Color.DarkRed, 1.2f, true);
55                 graphic.DrawString(CheckCode, font, brush, 2, 2);
56                 int X = 0; int Y = 0;
57                 //繪製圖片的前景噪點
58                 for (int i = 0; i < 100; i++)
59                 {
60                     X = random.Next(image.Width);
61                     Y = random.Next(image.Height);
62                     image.SetPixel(X, Y, Color.FromArgb(random.Next()));
63                 }
64                 //畫圖片的邊框線
65                 graphic.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
66                 //將圖片保存爲stream流返回
67                 MemoryStream ms = new MemoryStream();
68                 image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
69                 return ms;
70             }
71             finally
72             {
73                 graphic.Dispose();
74                 image.Dispose();
75             }
76         }
77     }

 生成驗證碼圖片，須要先生成驗證碼，再將驗證碼處理爲圖片。

轉載引用黎木博客-https://www.cnblogs.com/running-mydream/p/4071528.html