前台引用.aspx：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="YanZhengCode.aspx.cs" Inherits="YanZhengCode" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<img id="Image1" onclick="javascript:suiji();"src="YanZhengCode.aspx" alt="看不清楚，请单击我。" border="0"style="height:25px;60px;border: 0px; cursor: pointer;" />
<script language="javascript" type="text/javascript">
function suiji() {
document.getElementById("Image1").src = "gif_zl.aspx?chen=" + number;
}
</script>
</div>
</form>
</body>
</html>
YanZhengCode.cs
C#代码
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;
using System.IO;
using System;
public partial class YanZhengCode : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
//string str = Request["chen"];
BuildCode();
//ShuImg();
}
private void BuildCode()
{
Color[] strcolor = { Color.Red, Color.Blue, Color.Brown, Color.Black, Color.Tomato };
string[] strfont = { "华文中宋" };
Random rands = new Random();
Bitmap images = new Bitmap(80, 26); //图片大小
Graphics g = Graphics.FromImage(images);
Font f = new Font(strfont[0], 20); //字体大小
//笔刷填充色
Brush b = new SolidBrush(Color.Tomato);
Brush b2 = new SolidBrush(strcolor[rands.Next(0, strcolor.Length)]);
Brush b3 = new SolidBrush(Color.Red);
Brush b4 = new SolidBrush(Color.FromArgb(128, Color.Green));
g.Clear(Color.Wheat);
//线条颜色
Pen p = new Pen(Color.Red, 0);
Pen p2 = new Pen(Color.Turquoise, 0);
Random rand = new Random();
for (int i = 0; i < 40; i++)
{
int y = rand.Next(images.Height);
int x = rand.Next(images.Width);
//g.DrawLine(p, 0, y, images.Width, y);
g.DrawRectangle(p2, x, y, 1, 1);
}
//int degree = 5;
//Point tempPoint = new Point();
//degree = ~degree + 1;
//g.RotateTransform(degree);
//tempPoint.X = 20;
//tempPoint.Y = 4;
g.DrawRectangle(p, 0, 0, images.Width - 1, images.Height - 1); //绘图区域
string strCode = rand.Next(1000, 10000).ToString();
Session["yanzhencode"] = strCode;
g.DrawString(strCode.Substring(0, 1), f, b, 2, -1);
g.DrawString(strCode.Substring(1, 1), f, b2, 19, -1);
g.DrawString(strCode.Substring(2, 1), f, b3, 37, -1);
g.DrawString(strCode.Substring(3, 1), f, b4, 50, -1);
System.IO.MemoryStream ms = new System.IO.MemoryStream();
images.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
Response.ClearContent();
Response.ContentType = "image/jpeg";
Response.BinaryWrite(ms.ToArray());
//Response.Cookies.Add(new HttpCookie("chne", "6780"));
g.Dispose();
images.Dispose();
}
private void ShuImg()
{
Response.ContentType = "image/*"; //设置发送头为图像数据
Response.Clear(); //清空发送数据
Random rand = new Random();
Stream stream = OpenFile(Server.MapPath("pic/" + rand.Next(1, 6).ToString() + ".jpg")); //打开文件流
Bitmap bit = new Bitmap(stream);
bit.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);//保存到输出流中
stream.Close();
bit.Dispose();
Response.Flush(); //输出到客户端
}
}
**************************************二*******************
using System; using System.IO; using System.Drawing; using System.Drawing.Imaging; using System.Text; using System.Collections; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; /**//// <summary> /// /// ** asp.net(C#) 生成验证码 ** /// /// File: GenerateCheckCode.aspx.cs /// /// Author: 周振兴 (Zxjay 飘遥) /// /// E-Mail: tda7264@163.com /// /// Date: 07-04-10 /// /// </summary> public partial class GenerateCheckCode : System.Web.UI.Page ...{ protected void Page_Load(object sender, EventArgs e) ...{ string chkCode = string.Empty; //颜色列表，用于验证码、噪线、噪点 Color[] color =...{ Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue }; //字体列表，用于验证码 string[] font =...{ "Times New Roman", "MS Mincho", "Book Antiqua", "Gungsuh", "PMingLiU", "Impact" }; //验证码的字符集，去掉了一些容易混淆的字符 char[] character =...{ '2', '3', '4', '5', '6', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' }; Random rnd = new Random(); //生成验证码字符串 for (int i = 0; i < 4; i++) ...{ chkCode += character[rnd.Next(character.Length)]; } Bitmap bmp = new Bitmap(100, 40); Graphics g = Graphics.FromImage(bmp); g.Clear(Color.White); //画噪线 for (int i = 0; i < 10; i++) ...{ int x1 = rnd.Next(100); int y1 = rnd.Next(40); int x2 = rnd.Next(100); int y2 = rnd.Next(40); Color clr = color[rnd.Next(color.Length)]; g.DrawLine(new Pen(clr), x1, y1, x2, y2); } //画验证码字符串 for (int i = 0; i < chkCode.Length; i++) ...{ string fnt = font[rnd.Next(font.Length)]; Font ft = new Font(fnt, 18); Color clr = color[rnd.Next(color.Length)]; g.DrawString(chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 20 + 8, (float)8); } //画噪点 for (int i = 0; i < 100; i++) ...{ int x = rnd.Next(bmp.Width); int y = rnd.Next(bmp.Height); Color clr = color[rnd.Next(color.Length)]; bmp.SetPixel(x, y, clr); } //清除该页输出缓存，设置该页无缓存 Response.Buffer = true; Response.ExpiresAbsolute = System.DateTime.Now.AddMilliseconds(0); Response.Expires = 0; Response.CacheControl = "no-cache"; Response.AppendHeader("Pragma", "No-Cache"); //将验证码图片写入内存流，并将其以 "image/Png" 格式输出 MemoryStream ms = new MemoryStream(); try ...{ bmp.Save(ms, ImageFormat.Png); Response.ClearContent(); Response.ContentType = "image/Png"; Response.BinaryWrite(ms.ToArray()); } finally ...{ //显式释放资源 bmp.Dispose(); g.Dispose(); } } }
使用方法如下：
新建名为 GenerateCheckCode.aspx 的文件，将上述代码拷贝到代码文件 GenerateCheckCode.aspx.cs
在需要验证码的地方放置语句 <asp:Image ID="img1" runat="server" ImageUrl="~/GenerateCheckCode.aspx" /> 即可。