using
System;
using
System.Collections.Generic;
using
System.Linq;
using
System.Web;
using
System.Web.UI;
using
System.Web.UI.WebControls;
using
System.Text;
using
System.Drawing.Drawing2D;
using
System.Drawing;
using
System.IO;
using
System.Drawing.Imaging;
public
partial class ValidateCode : System.Web.UI.Page
{
private
string code;
private
const int ImageHeigth = 22; //验证码图片的高度
private
const double ImageLengthBase = 12.5; //验证码图片中每个字符的宽度
private
const int ImageLineNumber = 25; //噪音线的数量
private
const int ImagePointNumber = 100; //噪点的数量
private
int length;
public
static string VALIDATECODEKEY; //此处用来保存验证码到Session的Key的名称
//静态构造函数初始化验证码在Session中的Key名称
static
ValidateCode()
{
VALIDATECODEKEY =
"VALIDATECODEKEY";
}
//设置验证码的长度和内容
public
ValidateCode()
{
this
.length = 4;
this
.code =
string.Empty;
}
///
/// 产生随机的验证码并加入Session
///
/// 验证码长度
///
public
string CreateCode(int length)
{
if
(length <= 0)
{
return
string.Empty;
}
Random random =
new Random();
StringBuilder builder =
new StringBuilder();
//产生随机的验证码并拼接起来
for
(int i = 0; i < length; i++)
{
builder.Append(random.Next(0, 10));
}
this
.code = builder.ToString();
this
.Session[VALIDATECODEKEY] =
this.code;
return
this.code;
}
///
/// 根据长度产生验证码
/// 并将验证码画成图片
///
/// 验证码长度
public
void CreateValidateImage(int length)
{
this
.code =
this.CreateCode(length);
this
.CreateValidateImage(
this
.code);
}
///
/// 根据产生的验证码生成图片
///
/// 验证码
public
void CreateValidateImage(string code)
{
if
(!string.IsNullOrEmpty(code))
{
this
.Session[VALIDATECODEKEY] = code;
//初始化位图Bitmap对象，指定图片对象的大小(宽,高)
Bitmap image =
new Bitmap((int)Math.Ceiling((double)(code.Length * ImageLengthBase)), ImageHeigth);
//初始化一块画布
Graphics graphics = Graphics.FromImage(image);
Random random =
new Random();
try
{
int
num5;
graphics.Clear(Color.White);
//绘制噪音线
for
(num5 = 0; num5 < ImageLineNumber; num5++)
{
int
num = random.Next(image.Width);
int
num3 = random.Next(image.Height);
int
num2 = random.Next(image.Width);
int
num4 = random.Next(image.Height);
graphics.DrawLine(
new
Pen(Color.Silver), num, num3, num2, num4);
}
//验证码字体样式
Font font =
new Font("Tahoma", 12, FontStyle.Italic | FontStyle.Bold);
LinearGradientBrush brush =
new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
//绘制验证码到画布
graphics.DrawString(code, font, brush, (
float
)2, (
float
)2);
//绘制噪点
for
(num5 = 0; num5 < ImagePointNumber; num5++)
{
int
x = random.Next(image.Width);
int
y = random.Next(image.Height);
image.SetPixel(x, y, Color.FromArgb(random.Next()));
}
graphics.DrawRectangle(
new
Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
MemoryStream stream =
new MemoryStream();
//保存图片
image.Save(stream, ImageFormat.Gif);
base
.Response.ClearContent();
base
.Response.ContentType =
"image/Gif";
base
.Response.BinaryWrite(stream.ToArray());
}
finally
{
graphics.Dispose();
image.Dispose();
}
}
}
protected
override void OnLoad(EventArgs e)
{
this
.CreateValidateImage(
this
.length);
}
// Properties
public
string Code
{
get
{
return
this.Code;
}
}
public
int Length
{
get
{
return
this.length;
}
set
{
this
.length = value;
}
}
}
|
再次申明非本人原创。可以到网上下载ASPNETAJAXWeb.ValidateCode.dll直接使用