关于校验码
我想问一下校验码的问题。就是象CSDN登陆的时候需输入校验码。哪个是随机生成的吗？怎样做的？谢谢 问题点数：20、回复次数：3Top
1 楼lincent（微笑流浪）回复于 2006-03-31 13:29:21 得分 1
生成随机字符串，然后调用.net里的图片处理类生成图片就OK了Top
2 楼ruanruoshi（软若石）回复于 2006-03-31 13:31:32 得分 18
//
//
//已有一页生成的代码在项目CommonWeb/CreateCheckCode.aspx里，此代码作为备份代码存在。
//
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Web;
namespace XuLongClass
{
/// <summary>
/// CheckCode 的摘要说明。
/// </summary>
public class CheckCode : System.Web.UI.Page
{
public static string GenerateCheckCode()
{
int number;
char code;
string checkCode = String.Empty;
System.Random random = new Random();
for(int i=0; i<5; i++)
{
number = random.Next();
if(number % 2 == 0)
code = (char)('0' + (char)(number % 10));
else
code = (char)('A' + (char)(number % 26));
checkCode += code.ToString();
}
System.Web.HttpContext.Current.Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));
return checkCode;
}
public static 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();
//清空图片背景色
g.Clear(Color.White);
//画图片的背景噪音线
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 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);
System.Web.HttpContext.Current.Response.ClearContent();
System.Web.HttpContext.Current.Response.ContentType = "image/Gif";
System.Web.HttpContext.Current.Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
}
}
Top
3 楼fphuang（人在哈尔滨·四月）回复于 2006-03-31 13:39:46 得分 1
来看看我的控件及例子吧
http://202.118.164.104/djld/webform1.aspxTop
