asp.net中用C#生产验证码

来源：互联网发布：宜家代工工厂淘宝编辑：程序博客网时间：2024/05/16 23:53

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;

namespace MY_MIS
{
    public partial class CheckCode : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            this.CreateCheckCodeImage(GenerateCheckCode());
        }

        private string GenerateCheckCode()
        {
            int number;
            char code;
            string checkCode = String.Empty;

System.Random random = new Random();

            for (int i = 0; i < 6; i++)
            {
                number = random.Next();

                //if (number % 2 == 0)
                    code = (char)('0' + (char)(number % 10));
                //else
                //    code = (char)('A' + (char)(number % 26));

                checkCode += code.ToString();
            }
            Session["CheckCode"] = checkCode;

return checkCode;
}

        private void CreateCheckCodeImage(string checkCode)
        {
            if (checkCode == null || checkCode.Trim() == String.Empty)
                return;

System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
Graphics g = Graphics.FromImage(image);

            try
            {
                //生成随机生成器
                Random random = new Random();

//清空圖片背景色

g.Clear(Color.White);

//花图片的背景噪音色

                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 System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
                System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
                g.DrawString(checkCode, font, brush, 2, 2);

// 画图片的前景噪音点

                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);

                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
                Response.ClearContent();
                Response.ContentType = "image/Gif";
                Response.BinaryWrite(ms.ToArray());
            }
            finally
            {
                g.Dispose();
                image.Dispose();
            }
        }
    }
}

//显示验证码：可用以下方式在所需验证码的页面中调用产生验证码的页面