Question

ASP.NET第三方控件！

那个有ASP.Net第三方的空间，要显示 产生验证码的 最好是能产生中文的或是产生的是 4位数英文的！！谢谢

Answer 1

确认好评后，我给你一个随机不重复的4位英文+数字的验证码代码。

Answer 2

asp.net 图片验证码的制作--不用第三方控件的呢
直接放代码，要用的来取！
验证码图片生成文件 showimg.aspx.cs代码
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;
using System.Drawing.Imaging;
using System.IO;

public partial class _Default : 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.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)];
}
//保存验证码的Cookie
//HttpCookie anycookie = new HttpCookie("validateCookie");
// anycookie.Values.Add("ChkCode", chkCode);
//HttpContext.Current.Response.Cookies["validateCookie"].Values["ChkCode"] =chkCode;
Session["GetCode"] = chkCode;
Bitmap bmp = new Bitmap(150, 30);
Graphics g = Graphics.FromImage(bmp);
g.Clear(Color.White);
//画噪线
for (int i = 0; i < 5; i++)
{
int x1 = rnd.Next(150);
int y1 = rnd.Next(30);
int x2 = rnd.Next(150);
int y2 = rnd.Next(30);
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, 16);
Color clr = color[rnd.Next(color.Length)];
g.DrawString(chkCode.ToString(), ft, new SolidBrush(clr), (float)i * 20 +
20, (float)6);
}
//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();
}

}
}
调用验证码
if (TextBox3.Text.ToUpper() == Session["GetCode"].ToString())
{验证码正确执行的代码}
else{验证码错误执行的代码<br/>//Response.Write("<script lanuage=javascript>alert('验证码错误！');location='javascript:history.go(-1)'</script>");}
//说明：.ToUpper()是把所有字母转换成大写，因为我们的验证码都是大大写的！

Answer 3

http://www.evget.com/zh-CN/product/1252/feature.aspx

Answer 4

自己写个就是，这东西值得用个控件，百度一下就得了