如何判断校验码输入项TEXTBOX与形成的验证码图象生成的内容一致?
验证码类:CheckCode.aspx.cs
using System;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using System.Text;
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;
public partial class VCode : 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();
}
}
}
登陆项:
<td style= "width: 100px " align= "right ">
校验码: </td>
<td style= "width: 203px " align= "left ">
<asp:TextBox ID= "txtCheckCode " runat= "server " Width= "88px " OnTextChanged= "txtCheckCode_TextChanged "> </asp:TextBox>
</td>
[解决办法]
Session( "CheckCode1 ") = CheckCode;
=========================
改为：Session[ "CheckCode1 "] = CheckCode;
还有if语句里面也写错了，应改为：
if (txtCheckCode.Text != Session( "CheckCode1 ").tostring())
