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.Design;
using System.Drawing;
public partial class imagecode : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
this. CreateCheckCodeImage(RndNum());
}
private string RndNum()
{
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();
}
Response.Cookies.Add(new HttpCookie("yzmcode", checkCode));
return checkCode;
}
private 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 < 25; 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.Silver), 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);
Response.ClearContent();
Response.ContentType = "image/Gif";
Response.BinaryWrite(ms. ToArray());
}
finally
{
g.Dispose();
image. Dispose();
}
}
}
//验证码使用页login.aspx中的代码
<asp:ImageButton ID="yzm" runat="server" ImageUrl="imagecode.aspx" />
<asp:LinkButton ID="ChangeCode" runat="server" text="Can't see clearly? Change the verification code" />
<asp:Button ID="Button1" runat="server" Text="Button" /></div>
//ogin.aspx.cs中的代码
Add to
You don't need to write any code, click "Can't see clearly?" Change the verification code" to refresh the verification code later
protected void ChangeCode_Click(object sender, EventArgs e)
{
}
//提交按钮代码这里是通过cookies来验证的
protected void Button1_Click(object sender, EventArgs e)
{
if (String.Compare(Request.Cookies["yzmcode"]. Value, a.Text, true) != 0)
{
Response.Write("<scrip去掉t>alert('CAPTCHA error!')"</scrip去掉t>);
}
else
{ Response.Write("<scrip去掉t>alert('Validate!!')</scrip去掉t>"; }
}
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Posted on 4/2/2015 10:26:51 AM
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Posted on 4/4/2015 10:58:42 AM