随机生成验证码和图片

1.随机生成由数字和字母组成的验证码

 1         /// <summary>
 2         /// 生成由数字和字母组成的验证码
 3         /// </summary>
 4         /// <param name="length"></param>
 5         /// <returns></returns>
 6         public static string CreateValidateCodeWithStr(int length)
 7         {
 8             string str = @"0123456789abcdefghigklmnopqrstuvwxyzABCDEFGHIGKLMNOPQRSTUVWXYZ";
 9             StringBuilder validateNumberStr = new StringBuilder();
10             Random r = new Random();
11             for (int i = 0; i < length; i++)
12             {
13                 validateNumberStr.Append(str.Substring(0 + r.Next(61), 1));
14             }
15             return validateNumberStr.ToString();
16 
17

 

2.由验证码生成对应的图片

 1 /// <summary>
 2         /// 创建验证码的图片
 3         /// </summary>
 4         /// <param name="containsPage">要输出到的page对象</param>
 5         /// <param name="validateNum">验证码</param>
 6         public static byte[] CreateValidateGraphic(string validateCode)
 7         {
 8             Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 22);
 9             Graphics g = Graphics.FromImage(image);
10             try
11             {
12                 //生成随机生成器
13                 Random random = new Random();
14                 //清空图片背景色
15                 g.Clear(Color.White);
16                 //画图片的干扰线
17                 for (int i = 0; i < 25; i++)
18                 {
19                     int x1 = random.Next(image.Width);
20                     int x2 = random.Next(image.Width);
21                     int y1 = random.Next(image.Height);
22                     int y2 = random.Next(image.Height);
23                     g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
24                 }
25                 Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
26                 LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
27                  Color.Blue, Color.DarkRed, 1.2f, true);
28                 g.DrawString(validateCode, font, brush, 3, 2);
29                 //画图片的前景干扰点
30                 for (int i = 0; i < 100; i++)
31                 {
32                     int x = random.Next(image.Width);
33                     int y = random.Next(image.Height);
34                     image.SetPixel(x, y, Color.FromArgb(random.Next()));
35                 }
36                 //画图片的边框线
37                 g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
38                 //保存图片数据
39                 MemoryStream stream = new MemoryStream();
40                 image.Save(stream, ImageFormat.Jpeg);
41                 //输出图片流
42                 return stream.ToArray();
43             }
44             finally
45             {
46                 g.Dispose();
47                 image.Dispose();
48             }
49         }

3.在控制器中调用

1         public FileContentResult GetValidateCode()
2         {
3             string code = ValidateCode.CreateValidateCodeWithStr(4);
4             
5             return File(ValidateCode.CreateValidateGraphic(code),"image/jpeg");
6         }

4.在视图中调用

 1 <script>
 2     function RefValidateCode() {
 3         var r = Math.random();
 4         $("#img2").attr('src', '../Home/GetValidateCode?ashfjd=' + r + '');
 5     }
 6 </script>
 7 <div>
 8     <div style="padding: 40px;">       
 9         <img id="img2" src="@Url.Action("GetValidateCode", "Home")" onclick="RefValidateCode()" />
10     </div>
11 </div>

 

posted @ 2016-12-26 17:29  花生打代码会头痛  阅读(238)  评论(0)    收藏  举报