C#..

/*反射工厂关键代码*/

 

 

 

namespace GameCardSale.DALFactory
{
    /// <summary>
    /// 提供数据访问实体的工厂
    /// </summary>
    public sealed class DataAccess
    {
        //数据集名称        
        private static readonly string dalFile =  ConfigurationManager.AppSettings["WebDAL"];
        //命名空间
        private static readonly string nameSpace = ConfigurationManager.AppSettings["NameSpace"];

        #region UserInfoService
        /// <summary>
        /// 获取对 UserInfo 表的数据访问实体
        /// </summary>
        /// <returns></returns>
        public static GameCardSale.IDAL.IUserInfoService CreateUserInfoService()
        {
            return Assembly.Load(dalFile).CreateInstance(nameSpace + ".UserInfoService") as IUserInfoService;
        }
        #endregion
    }
}

 

 

 

 

/*Csharp 验证码 */

 

public class ValidateCode : System.Web.UI.Page
 {
  private void Page_Load(object sender, System.EventArgs e)
  {
   this.CreateCheckCodeImage(GenerateCheckCode());
  }

  #region Web 窗体设计器生成的代码
  override protected void OnInit(EventArgs e)
  {
   //
   // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
   //
   InitializeComponent();
   base.OnInit(e);
  }
  
  /// <summary>
  /// 设计器支持所需的方法 - 不要使用代码编辑器修改
  /// 此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {    
   this.Load += new System.EventHandler(this.Page_Load);
  }
  #endregion

  private 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();
   }

   Response.Cookies.Add(new HttpCookie("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);
    Response.ClearContent();
    Response.ContentType = "image/Gif";
    Response.BinaryWrite(ms.ToArray());
   }
   finally
   {
    g.Dispose();
    image.Dispose();
   }
  }
 }

 

 

　　假如以上验证码生成器页面名为：CheckCode.aspx ，那么在登录页面中使用“<IMG> ” 这个 HTML 元素来显示生成的验证码图片：<IMG src ="CheckCode.aspx ">
　　在登录页面的登录按钮的处理事件中使用以下代码判断验证码：

  private void btnLogin_Click(object sender, System.Web.UI.ImageClickEventArgs e)
  {
   if (Request.Cookies["CheckCode "] == null)
   {
    lblMessage.Text = "您的浏览器设置已被禁用 Cookies，您必须设置浏览器允许使用 Cookies 选项后才能使用本系统。";
    lblMessage.Visible = true;
    return ;
   }

   if (String.Compare(Request.Cookies["CheckCode "].Value, txtCheckCode.Text, true ) != 0)
   {
    lblMessage.Text = "验证码错误，请输入正确的验证码。";
    lblMessage.Visible = true;
    return ;
   }

 

----------------------------------------------------------------------------------------------------------------------------------

 

设置网页过期:

<!--禁用缓存部分开始--> 
<meta http-equiv="Expires" content="0" /> 
<meta http-equiv="Progma" content="no-cache" /> 
<meta http-equiv="cache-control" content="no-cache,must-revalidate" /> 
<!--禁用缓存部分结束--> 


ASP.net 代码如下： 
放在页面代码Page_Onload 
  HttpContext.Current.Response.Expires = 0; 
  Response.ExpiresAbsolute = DateTime.Now - 1; 
  Response.AddHeader("progma", "no-cache"); 
  Response.AddHeader("cache-control", "private"); 
  Response.CacheControl = "no-cache"; 

PHP网页   
  header("Expires:   Mon,   26   Jul   1997   05:00:00   GMT");   
  header("Cache-Control:   no-cache,   must-revalidate");   
  header("Pragma:   no-cache");


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