生成图片验证码-蒲公英云

生成图片验证码

原地址：http://www.cnblogs.com/luminji/p/4794453.html

控制器部分：

///

/// 验证码
///

///
public ActionResult CheckCode()
{
//首先实例化验证码的类
ValidateCode validateCode = new ValidateCode();
//生成验证码指定的长度
string code = validateCode.CreateValidateCode(4);
//创建验证码的图片
byte[] bytes = validateCode.CreateValidateGraphic(code);
//最后将验证码返回
return File(bytes, @”image/jpeg”);
}

工具类：

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace TMinjiP2P.Utility.Web
{
public class ValidateCode
{
///

/// 验证码的最大长度
///

public int MaxLength
{
get { return 10; }
}

    /// <summary>  
    /// 验证码的最小长度  
    /// </summary>  
    public int MinLength  
    \{  
        get \{ return 4; \}  
    \}
    /// <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;  
    \}
    //C\# MVC 升级版  
    /// <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;  
    \}
\}