我找到一个 c#经典验证码源代码..但是不会使用...
我知道把生成的这个图片弄到页面上去.但不知道怎么对比...
求求你们再帮助我一次吧!!谢谢!!!
-----
ASP.net 验证码(C#)
/* Copyright all(c) 2005 ZhongFeng, http://blog.csdn.net/SW515 */
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();
}
}
}
我知道把生成的这个图片弄到页面上去.但不知道怎么对比...
求求你们再帮助我一次吧!!谢谢!!!
-----
ASP.net 验证码(C#)
/* Copyright all(c) 2005 ZhongFeng, http://blog.csdn.net/SW515 */
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();
}
}
}
这代码有内存漏洞~
“System.IO.MemoryStream ms = new System.IO.MemoryStream();”
既然用了非托管资源就要在后面释放:
ms.Close();
ms.Dispose();
---请问有必要吗?要怎么修改?
你在d.aspx要引用这个验证码。那就再d.aspx里面写一个<img src="v.aspx" alt="验证码"/>;
这样图片就会显示验证码了。即src的值就是你验证码的页面!你要读取那就很简单拉,验证码页面是把验证码码放入cookies的
Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));
根据以上那句可以知道cookies的key为CheckCode,
那么你可以根据文本框内容和该cookies的值比较。如果一样则验证码正确!
拆成3句
string checkcode = GenerateCheckCode();
Session["CheckCode"] = checkcode ;
CreateCheckCodeImage(checkcode );
判断用:
if(文本框.Text == Session["CheckCode"].ToString())
{
//正确
}
else
{
//错误
}