代码
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Drawing;
namespace SessionCode
{
public partial class checkimage : System.Web.UI.Page
{
/// <summary>
/// 验证码产生程序
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Page_Load(object sender, EventArgs e)
{
GetCode();
}
//产生code
protected void GetCode()
{
System.Random rand = new Random();
int len = 4; //这里设置验证码长度，我的定义为4，最近见到些网上上有随机4，5，6位的。这里自己写个随机函数就可以了。
char[] chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray();
System.Text.StringBuilder myStr = new System.Text.StringBuilder();
for (int iCount = 0; iCount < len; iCount++)
{
myStr.Append(chars[rand.Next(chars.Length)]);
}
string text = myStr.ToString();
// 保存验证码到 session 中以便其他模块使用
Session["code"] = text; //这里你的登陆页面判断输入验证码是否正确，if (txtCode.text == Session["code"]) 正确读库检索User/Password,不正确弹窗。自己写
Size ImageSize = Size.Empty;
Font myFont = new Font("MS Sans Serif", 12); //绘制在验证图片上的文字大小
// 计算验证码图片大小
using (Bitmap bmp = new Bitmap(5, 5))
{
using (Graphics g = Graphics.FromImage(bmp))
{
SizeF size = g.MeasureString(text, myFont, 10000);
ImageSize.Width = (int)size.Width + 3;
ImageSize.Height = (int)size.Height + 3;
}
}
// 创建验证码图片
using (Bitmap bmp = new Bitmap(ImageSize.Width, ImageSize.Height))
{
// 绘制验证码文本
using (Graphics g = Graphics.FromImage(bmp))
{
g.Clear(Color.White);
using (StringFormat f = new StringFormat())
{
f.Alignment = StringAlignment.Near;
f.LineAlignment = StringAlignment.Center;
f.FormatFlags = StringFormatFlags.NoWrap;
g.DrawString(text, myFont, Brushes.Black, new RectangleF(0, 0, ImageSize.Width, ImageSize.Height), f);
}//using
}//using
// 制造杂点 杂点面积占图片面积的 20%
int num = ImageSize.Width * ImageSize.Height * 20 / 100;
for (int iCount = 0; iCount < num; iCount++)
{
// 在随机的位置使用随机的颜色设置图片的像素
int x = rand.Next(ImageSize.Width);
int y = rand.Next(ImageSize.Height);
int r = rand.Next(255);
int g = rand.Next(255);
int b = rand.Next(255);
Color c = Color.FromArgb(r, g, b);
bmp.SetPixel(x, y, c);
}//for
// 输出图片
System.IO.MemoryStream ms = new System.IO.MemoryStream();
bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
this.Response.ContentType = "image/png";
ms.WriteTo(this.Response.OutputStream);
ms.Close();
}//using
myFont.Dispose();
}
}
}
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Drawing;
namespace SessionCode
{
public partial class checkimage : System.Web.UI.Page
{
/// <summary>
/// 验证码产生程序
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Page_Load(object sender, EventArgs e)
{
GetCode();
}
//产生code
protected void GetCode()
{
System.Random rand = new Random();
int len = 4; //这里设置验证码长度，我的定义为4，最近见到些网上上有随机4，5，6位的。这里自己写个随机函数就可以了。
char[] chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray();
System.Text.StringBuilder myStr = new System.Text.StringBuilder();
for (int iCount = 0; iCount < len; iCount++)
{
myStr.Append(chars[rand.Next(chars.Length)]);
}
string text = myStr.ToString();
// 保存验证码到 session 中以便其他模块使用
Session["code"] = text; //这里你的登陆页面判断输入验证码是否正确，if (txtCode.text == Session["code"]) 正确读库检索User/Password,不正确弹窗。自己写
Size ImageSize = Size.Empty;
Font myFont = new Font("MS Sans Serif", 12); //绘制在验证图片上的文字大小
// 计算验证码图片大小
using (Bitmap bmp = new Bitmap(5, 5))
{
using (Graphics g = Graphics.FromImage(bmp))
{
SizeF size = g.MeasureString(text, myFont, 10000);
ImageSize.Width = (int)size.Width + 3;
ImageSize.Height = (int)size.Height + 3;
}
}
// 创建验证码图片
using (Bitmap bmp = new Bitmap(ImageSize.Width, ImageSize.Height))
{
// 绘制验证码文本
using (Graphics g = Graphics.FromImage(bmp))
{
g.Clear(Color.White);
using (StringFormat f = new StringFormat())
{
f.Alignment = StringAlignment.Near;
f.LineAlignment = StringAlignment.Center;
f.FormatFlags = StringFormatFlags.NoWrap;
g.DrawString(text, myFont, Brushes.Black, new RectangleF(0, 0, ImageSize.Width, ImageSize.Height), f);
}//using
}//using
// 制造杂点 杂点面积占图片面积的 20%
int num = ImageSize.Width * ImageSize.Height * 20 / 100;
for (int iCount = 0; iCount < num; iCount++)
{
// 在随机的位置使用随机的颜色设置图片的像素
int x = rand.Next(ImageSize.Width);
int y = rand.Next(ImageSize.Height);
int r = rand.Next(255);
int g = rand.Next(255);
int b = rand.Next(255);
Color c = Color.FromArgb(r, g, b);
bmp.SetPixel(x, y, c);
}//for
// 输出图片
System.IO.MemoryStream ms = new System.IO.MemoryStream();
bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
this.Response.ContentType = "image/png";
ms.WriteTo(this.Response.OutputStream);
ms.Close();
}//using
myFont.Dispose();
}
}
}
