验证码 使用语言 ASP.NET
1.首先建立一个aspx页面。在后台cs文件中写入如下代码
注意:应用DLLusing System.Drawing;
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 WebApplication1
{
public partial class yanzhegnma : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
CreateCheckCodeImage(GenerateCheckCode());
}
public static string GenerateCheckCode()
{
int number;
char code;
string checkCode = String.Empty;
System.Random random = new Random();
for (int i = 0; i < 4; i++)
{
number = random.Next();
if (number % 2 == 0)
code = (char)('0' + (char)(number % 10));
else
code = (char)('A' + (char)(number % 26));
checkCode += code.ToString();
}
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 < 2; 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.Black), 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);
HttpContext.Current.Response.ClearContent();
HttpContext.Current.Response.ContentType = "image/Gif";
HttpContext.Current.Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
}
}
第二部 在用到验证码的地方写入如下代码
<form id="form1" runat="server">
<div>
<img alt="刷新" onclick="this.src='yanzhegnma.aspx?id=' + Math.random() * 10000" src="yanzhegnma.aspx"
style="width: 295px" />
</div>
</form>
具体逻辑和注意事件应用的文件名称。切记。 这是简单的验证码实现方法。小程序仅供娱乐。。。黑桃K