[原创]红马版验证码实现（中文+变形+噪点）

<%
@ Page Language
=
"
C#
"

%>



<!
DOCTYPE html PUBLIC
"
-//W3C//DTD XHTML 1.0 Transitional//EN
"

"
http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd
"
>



<
script runat
=
"
server
"
>


protected

void
Page_Load(
object
sender, EventArgs e)
{
VryImgGen gen
=

new
VryImgGen();

string
verifyCode
=
gen.CreateVerifyCode(
5
,
1
);
Session[
"
VerifyCode
"
]
=
verifyCode.ToUpper();
System.Drawing.Bitmap bitmap
=
gen.CreateImage(verifyCode);
System.IO.MemoryStream ms
=

new
System.IO.MemoryStream();
bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
Response.Clear();
Response.ContentType
=

"
image/Png
"
;
Response.BinaryWrite(ms.GetBuffer());
bitmap.Dispose();
ms.Dispose();
ms.Close();
Response.End();
}

</
script
>

using
System;

using
System.Data;

using
System.Configuration;

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.Text;


///

<summary>


///
Summary description for VryImgGen

///

</summary>


public
partial
class
VryImgGen
{


///

<summary>


///
供验证码生成汉字时选取的汉字集,若为空则按照《GB2312简体中文编码表》编码规则构造汉字

///

</summary>



public

static

string
ChineseChars
=
String.Empty;


///

<summary>


///
英文与数字串

///

</summary>



protected

static

readonly

string
EnglishOrNumChars
=

"
0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ
"
;


public
VryImgGen()
{
rnd
=

new
Random(
unchecked
((
int
)DateTime.Now.Ticks));
}


///

<summary>


///
全局随机数生成器

///

</summary>



private
Random rnd;


int
length
=

5
;

///

<summary>


///
验证码长度(默认6个验证码的长度)

///

</summary>



public

int
Length
{

get
{
return
length; }

set
{ length
=
value; }
}


int
fontSize
=

18
;

///

<summary>


///
验证码字体大小(为了显示扭曲效果，默认30像素，可以自行修改)

///

</summary>



public

int
FontSize
{

get
{
return
fontSize; }

set
{ fontSize
=
value; }
}


int
padding
=

4
;

///

<summary>


///
边框补(默认4像素)

///

</summary>



public

int
Padding
{

get
{
return
padding; }

set
{ padding
=
value; }
}


bool
chaos
=

true
;

///

<summary>


///
是否输出燥点(默认输出)

///

</summary>



public

bool
Chaos
{

get
{
return
chaos; }

set
{ chaos
=
value; }
}

Color chaosColor
=
Color.LightGray;

///

<summary>


///
输出燥点的颜色(默认灰色)

///

</summary>



public
Color ChaosColor
{

get
{
return
chaosColor; }

set
{ chaosColor
=
value; }
}

Color backgroundColor
=
Color.White;

///

<summary>


///
自定义背景色(默认白色)

///

</summary>



public
Color BackgroundColor
{

get
{
return
backgroundColor; }

set
{ backgroundColor
=
value; }
}

Color[] colors
=
{ Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };

///

<summary>


///
自定义随机颜色数组

///

</summary>



public
Color[] Colors
{

get
{
return
colors; }

set
{ colors
=
value; }
}


string
[] fonts
=
{
"
Arial
"
,
"
Georgia
"
};

///

<summary>


///
自定义字体数组

///

</summary>



public

string
[] Fonts
{

get
{
return
fonts; }

set
{ fonts
=
value; }
}


#region
产生波形滤镜效果



private

const

double
PI
=

3.1415926535897932384626433832795
;

private

const

double
PI2
=

6.283185307179586476925286766559
;


///

<summary>


///
正弦曲线Wave扭曲图片（Edit By 51aspx.com）

///

</summary>


///

<param name="srcBmp">
图片路径
</param>


///

<param name="bXDir">
如果扭曲则选择为True
</param>


///

<param name="nMultValue">
波形的幅度倍数，越大扭曲的程度越高，一般为3
</param>


///

<param name="dPhase">
波形的起始相位，取值区间[0-2*PI)
</param>


///

<returns></returns>



public
System.Drawing.Bitmap TwistImage(Bitmap srcBmp,
bool
bXDir,
double
dMultValue,
double
dPhase)
{
System.Drawing.Bitmap destBmp
=

new
Bitmap(srcBmp.Width, srcBmp.Height);


//
将位图背景填充为白色


System.Drawing.Graphics graph
=
System.Drawing.Graphics.FromImage(destBmp);
graph.FillRectangle(
new
SolidBrush(System.Drawing.Color.White),
0
,
0
, destBmp.Width, destBmp.Height);
graph.Dispose();


double
dBaseAxisLen
=
bXDir
?
(
double
)destBmp.Height : (
double
)destBmp.Width;


for
(
int
i
=

0
; i
<
destBmp.Width; i
++
)
{

for
(
int
j
=

0
; j
<
destBmp.Height; j
++
)
{

double
dx
=

0
;
dx
=
bXDir
?
(PI2
*
(
double
)j)
/
dBaseAxisLen : (PI2
*
(
double
)i)
/
dBaseAxisLen;
dx
+=
dPhase;

double
dy
=
Math.Sin(dx);


//
取得当前点的颜色



int
nOldX
=

0
, nOldY
=

0
;
nOldX
=
bXDir
?
i
+
(
int
)(dy
*
dMultValue) : i;
nOldY
=
bXDir
?
j : j
+
(
int
)(dy
*
dMultValue);

System.Drawing.Color color
=
srcBmp.GetPixel(i, j);

if
(nOldX
>=

0

&&
nOldX
<
destBmp.Width

&&
nOldY
>=

0

&&
nOldY
<
destBmp.Height)
{
destBmp.SetPixel(nOldX, nOldY, color);
}
}
}


return
destBmp;
}




#endregion



///

<summary>


///
生成校验码图片

///

</summary>


///

<param name="code">
验证码
</param>


///

<returns></returns>



public
Bitmap CreateImage(
string
code)
{

int
fSize
=
FontSize;

int
fWidth
=
fSize
+
Padding;


int
imageWidth
=
(
int
)(code.Length
*
fWidth)
+

4

+
Padding
*

2
;

int
imageHeight
=
fSize
*

2

+
Padding
*

2
;

System.Drawing.Bitmap image
=

new
System.Drawing.Bitmap(imageWidth, imageHeight);

Graphics g
=
Graphics.FromImage(image);

g.Clear(BackgroundColor);


//
给背景添加随机生成的燥点



if
(
this
.Chaos)
{

Pen pen
=

new
Pen(ChaosColor,
0
);

int
c
=
Length
*

10
;


for
(
int
i
=

0
; i
<
c; i
++
)
{

int
x
=
rnd.Next(image.Width);

int
y
=
rnd.Next(image.Height);

g.DrawRectangle(pen, x, y,
1
,
1
);
}
}


int
left
=

0
, top
=

0
, top1
=

1
, top2
=

1
;


int
n1
=
(imageHeight
-
FontSize
-
Padding
*

2
);

int
n2
=
n1
/

4
;
top1
=
n2;
top2
=
n2
*

2
;

Font f;
Brush b;


int
cindex, findex;


//
随机字体和颜色的验证码字符



for
(
int
i
=

0
; i
<
code.Length; i
++
)
{
cindex
=
rnd.Next(Colors.Length
-

1
);
findex
=
rnd.Next(Fonts.Length
-

1
);

f
=

new
System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold);
b
=

new
System.Drawing.SolidBrush(Colors[cindex]);


if
(i
%

2

==

1
)
{
top
=
top2;
}

else

{
top
=
top1;
}

left
=
i
*
fWidth;

g.DrawString(code.Substring(i,
1
), f, b, left, top);
}


//
画一个边框 边框颜色为Color.Gainsboro


g.DrawRectangle(
new
Pen(Color.Gainsboro,
0
),
0
,
0
, image.Width
-

1
, image.Height
-

1
);
g.Dispose();


//
产生波形（Add By 51aspx.com）


image
=
TwistImage(image,
true
,
8
,
4
);


return
image;
}


///

<summary>


///
生成随机字符码

///

</summary>


///

<param name="codeLen">
字符串长度
</param>


///

<param name="zhCharsCount">
中文字符数
</param>


///

<returns></returns>



public

string
CreateVerifyCode(
int
codeLen,
int
zhCharsCount)
{

char
[] chs
=

new

char
[codeLen];


int
index;

for
(
int
i
=

0
; i
<
zhCharsCount; i
++
)
{
index
=
rnd.Next(
0
, codeLen);

if
(chs[index]
==

'
\0
'
)
chs[index]
=
CreateZhChar();

else


--
i;
}

for
(
int
i
=

0
; i
<
codeLen; i
++
)
{

if
(chs[i]
==

'
\0
'
)
chs[i]
=
CreateEnOrNumChar();
}


return

new

string
(chs,
0
, chs.Length);
}


///

<summary>


///
生成默认长度5的随机字符码

///

</summary>


///

<returns></returns>



public

string
CreateVerifyCode()
{

return
CreateVerifyCode(Length,
0
);
}


///

<summary>


///
生成英文或数字字符

///

</summary>


///

<returns></returns>



protected

char
CreateEnOrNumChar()
{

return
EnglishOrNumChars[rnd.Next(
0
, EnglishOrNumChars.Length)];
}


///

<summary>


///
生成汉字字符

///

</summary>


///

<returns></returns>



protected

char
CreateZhChar()
{

//
若提供了汉字集，查询汉字集选取汉字



if
(ChineseChars.Length
>

0
)
{

return
ChineseChars[rnd.Next(
0
, ChineseChars.Length)];
}

//
若没有提供汉字集，则根据《GB2312简体中文编码表》编码规则构造汉字



else

{

byte
[] bytes
=

new

byte
[
2
];


//
第一个字节值在0xb0, 0xf7之间


bytes[
0
]
=
(
byte
)rnd.Next(
0xb0
,
0xf8
);

//
第二个字节值在0xa1, 0xfe之间


bytes[
1
]
=
(
byte
)rnd.Next(
0xa1
,
0xff
);


//
根据汉字编码的字节数组解码出中文汉字



string
str1
=
Encoding.GetEncoding(
"
gb2312
"
).GetString(bytes);


return
str1[
0
];
}
}
}

<
img
src
="VerifyCode.aspx"
id
="valiCode"
alt
="验证码"

/>


<
a
title
="刷新验证码"
href
="#"
onclick
="javascript:document.getElementById('valiCode').src='VerifyCode.aspx?id='+Math.random();return false;"
>
看不清，换张图片？
</
a
>