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;
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public partial class ValidateCode : System.Web.UI.Page
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{
protected void Page_Load(object sender, EventArgs e)
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{
this.CreateCheckCodeImage(GenerateCheckCode());
}
private string GenerateCheckCode()
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{
int number;
char code;
string checkCode = String.Empty;
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System.Random random = new Random();
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for (int i = 0; i < 5; i++)
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{
number = random.Next();
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if (number % 2 == 0)
code = (char)('0' + (char)(number % 10));
else
code = (char)('A' + (char)(number % 26));
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
checkCode += code.ToString();
}
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Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));
Session["CheckCode"] = checkCode;//用于客户端校验码比较
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return checkCode;
}
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private void CreateCheckCodeImage(string checkCode)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
if (checkCode == null || checkCode.Trim() == String.Empty)
return;
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
Graphics g = Graphics.FromImage(image);
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
try
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{
//生成随机生成器
Random random = new Random();
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
//清空图片背景色
g.Clear(Color.White);
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//画图片的背景噪音线
for (int i = 0; i < 25; i++)
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{
int x1 = random.Next(image.Width);
int x2 = random.Next(image.Width);
int y1 = random.Next(image.Height);
int y2 = random.Next(image.Height);
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
}
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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);
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
//画图片的前景噪音点
for (int i = 0; i < 100; i++)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
int x = random.Next(image.Width);
int y = random.Next(image.Height);
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
image.SetPixel(x, y, Color.FromArgb(random.Next()));
}
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
//画图片的边框线
g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
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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
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
g.Dispose();
image.Dispose();
}
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}
}
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)