前台生成验证码案例

cshtml注册页面

<img id="valiCode" style="cursor: pointer;" onclick="this.src = '@Url.Action("GetValidateCode", "Account")?time=' + (new Date()).getTime();" src="GetValidateCode" alt="验证码" />
</br>
新建一个GetValidateCode页面

@{
ViewBag.Title = "GetValidateCode";
}

@Html.Action("GetValidateCode", "Account");
</br>
验证码实体类

using System;

using System.Drawing;

using System.Drawing.Imaging;

using System.Web.UI;

using System.Drawing.Drawing2D;

using System.IO;

namespace Game.Entity.Accounts
{
/// <summary>

/// 生成验证码的类

/// </summary>

public class ValidateCode
{

public ValidateCode()
{

}

/// <summary>
/// 验证码的最大长度
/// </summary>
public int MaxLength
{

get { return 10; }

}
/// <summary>
/// 验证码的最小长度
/// </summary>
public int MinLength
{

get { return 1; }

}
/// <summary>
/// 生成验证码
/// </summary>
/// <param name="length">指定验证码的长度</param>
/// <returns></returns>
public string CreateValidateCode(int length)
{

int[] randMembers = new int[length];

int[] validateNums = new int[length];

string validateNumberStr = "";

//生成起始序列值

int seekSeek = unchecked((int)DateTime.Now.Ticks);

Random seekRand = new Random(seekSeek);

int beginSeek = (int)seekRand.Next(0, Int32.MaxValue - length * 10000);

int[] seeks = new int[length];

for (int i = 0; i < length; i++)
{

beginSeek += 10000;

seeks[i] = beginSeek;

}

//生成随机数字

for (int i = 0; i < length; i++)
{

Random rand = new Random(seeks[i]);

int pownum = 1 * (int)Math.Pow(10, length);

randMembers[i] = rand.Next(pownum, Int32.MaxValue);

}

//抽取随机数字

for (int i = 0; i < length; i++)
{

string numStr = randMembers[i].ToString();

int numLength = numStr.Length;

Random rand = new Random();

int numPosition = rand.Next(0, numLength - 1);

validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));

}

//生成验证码

for (int i = 0; i < length; i++)
{

validateNumberStr += validateNums[i].ToString();

}

return validateNumberStr;

}
/// <summary>
/// 创建验证码的图片
/// </summary>
/// <param name="containsPage">要输出到的page对象</param>
/// <param name="validateNum">验证码</param>
public byte[] CreateValidateGraphic(string validateCode)
{

Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 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);

//画图片的干扰线

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 Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));

LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),

Color.Blue, Color.DarkRed, 1.2f, true);

g.DrawString(validateCode, font, brush, 3, 2);

//画图片的前景干扰点

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);

//保存图片数据

MemoryStream stream = new MemoryStream();

image.Save(stream, ImageFormat.Jpeg);

//输出图片流

return stream.ToArray();

}

finally
{

g.Dispose();

image.Dispose();

}

}
/// <summary>
/// 得到验证码图片的长度
/// </summary>
/// <param name="validateNumLength">验证码的长度</param>
/// <returns></returns>
public static int GetImageWidth(int validateNumLength)
{

return (int)(validateNumLength * 12.0);

}
/// <summary>
/// 得到验证码的高度
/// </summary>
/// <returns></returns>
public static double GetImageHeight()
{

return 22.5;

}

}
}

控制器代码
/// <summary>
/// 验证码
/// </summary>
/// <returns></returns>
[AllowAnonymous]
public ActionResult GetValidateCode()
{

ValidateCode vCode = new ValidateCode();

string code = vCode.CreateValidateCode(5);

Session["ValidateCode"] = code;

byte[] bytes = vCode.CreateValidateGraphic(code);

return File(bytes, @"image/jpeg");

}

登录验证

Session["ValidateCode"].ToString() != model.code