------生成方法一
pageload（object sender, eventarges 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();
}
}
------生成方法二
<%@ WebHandler Language="C#" class="yzCodeHandler" %>
using System;
using System.Web;
using System.Drawing;
public class yzCodeHandler : IHttpHandler , System.Web.SessionState.IRequiresSessionState
{
public string charSet = "2,3,4,5,6,8,9,A,B,C,D,E,F,G,H,J,K,M,N,P,R,S,U,W,X,Y";
public void ProcessRequest (HttpContext context) {
string validateCode = CreateRandomCode(4);
context.Session["ValidateCode"] = validateCode;
CreateImage(validateCode, context);
}
public bool IsReusable {
get {
return false;
}
}
/// <summary>
/// 生成验证码
/// <param name="n">位数</param>
/// <returns>验证码字符串</returns>
private string CreateRandomCode(int n)
{
string[] CharArray = charSet.Split(',');
string randomCode = "";
int temp = -1;
Random rand = new Random();
for (int i = 0; i < n; i++)
{
if (temp != -1)
{
rand = new Random(i * temp * ((int)DateTime.Now.Ticks));
} int t = rand.Next(CharArray.Length - 1);
if (temp == t) {
return CreateRandomCode(n);
} temp = t;
randomCode += CharArray[t];
}
return randomCode;
}
private void CreateImage(string checkCode, HttpContext context)
{
int iwidth = (int)(checkCode.Length * 13);
System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 23);
Graphics g = Graphics.FromImage(image);
Font f = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Italic | System.Drawing.FontStyle.Bold)); // 前景色
Brush b = new System.Drawing.SolidBrush(Color.Black); // 背景色
g.Clear(Color.White); // 填充文字
g.DrawString(checkCode, f, b, 0, 1); // 随机线条
Pen linePen = new Pen(Color.Gray, 0); Random rand = new Random();
for (int i = 0; i < 5; i++) {
int x1 = rand.Next(image.Width);
int y1 = rand.Next(image.Height);
int x2 = rand.Next(image.Width);
int y2 = rand.Next(image.Height);
g.DrawLine(linePen, x1, y1, x2, y2);
} // 随机点
for (int i = 0; i < 30; i++)
{
int x = rand.Next(image.Width);
int y = rand.Next(image.Height);
image.SetPixel(x, y, Color.Gray);
} // 边框
g.DrawRectangle(new Pen(Color.Gray), 0, 0, image.Width - 1, image.Height - 1); // 输出图片
System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
context.Response.ClearContent();
context.Response.ContentType = "image/Jpeg";
context.Response.BinaryWrite(ms.ToArray());
g.Dispose();
image.Dispose();
}
}
----------------
验证方法
if (txtValidateCode.Text.ToUpper().Trim() == Session["ValidateCode"].ToString().ToUpper().Trim())
{
//true
}
else
{
//false
}