一、验证码简介
验证码功能一般是用于防止批量注册的,不少网站为了防止用户利用机器人自动注册、登录、灌水,都采用了验证码技术。所谓验证码,就是将一串随机产生的数字或字母或符号或文字,生成一幅图片, 图片里加上一些干扰象素(防止OCR),由用户肉眼识别其中的验证码信息,输入表单提交网站验证,验证成功后才能使用某项功能。
常见的验证码有如下几种:
1、纯数字验证码,一般为四位随机数字;
2、数字+字母验证码,一般从数字(0~9)和字母(A~Z和a~z)中随机抽出几个字符组成;
3、汉字验证码,相对而言,这种验证码比较少见一点,实现起来也相对复杂一些,但在不少网站中还是可以看到的;
验证码功能一般是用于防止批量注册的,不少网站为了防止用户利用机器人自动注册、登录、灌水,都采用了验证码技术。所谓验证码,就是将一串随机产生的数字或字母或符号或文字,生成一幅图片, 图片里加上一些干扰象素(防止OCR),由用户肉眼识别其中的验证码信息,输入表单提交网站验证,验证成功后才能使用某项功能。
常见的验证码有如下几种:
1、纯数字验证码,一般为四位随机数字;
2、数字+字母验证码,一般从数字(0~9)和字母(A~Z和a~z)中随机抽出几个字符组成;
3、汉字验证码,相对而言,这种验证码比较少见一点,实现起来也相对复杂一些,但在不少网站中还是可以看到的;
二、验证码的实现
1、纯数字验证码的实现
纯数字验证码的实现相对比较简单,可通过以下两种方法来实现
(1)使用随机数方式,代码如下:
private
String GetRandomint(
int
codeCount)
{
Random random = new Random();
string min = "" ;
string max = "" ;
for ( int i = 0 ; i < codeCount; i ++ )
{
min += " 1 " ;
max += " 9 " ;
}
return (random.Next(Convert.ToInt32(min),Convert.ToInt32(max)).ToString());
}
{
Random random = new Random();
string min = "" ;
string max = "" ;
for ( int i = 0 ; i < codeCount; i ++ )
{
min += " 1 " ;
max += " 9 " ;
}
return (random.Next(Convert.ToInt32(min),Convert.ToInt32(max)).ToString());
}
(2)使用随机组合方式,代码如下:
private
string
CreateRandomCode(
int
codeCount)
{
string allChar = " 0,1,2,3,4,5,6,7,8,9 " ;
string [] allCharArray = allChar.Split( ' , ' );
string randomCode = "" ;
int temp = - 1 ;
Random rand = new Random();
for ( int i = 0 ; i < codeCount; i ++ )
{
if (temp != - 1 )
{
rand = new Random(i * temp * (( int )DateTime.Now.Ticks));
}
int t = rand.Next( 9 );
if (temp == t)
{
return CreateRandomCode(codeCount);
}
temp = t;
randomCode += allCharArray[t];
}
return randomCode;
}
{
string allChar = " 0,1,2,3,4,5,6,7,8,9 " ;
string [] allCharArray = allChar.Split( ' , ' );
string randomCode = "" ;
int temp = - 1 ;
Random rand = new Random();
for ( int i = 0 ; i < codeCount; i ++ )
{
if (temp != - 1 )
{
rand = new Random(i * temp * (( int )DateTime.Now.Ticks));
}
int t = rand.Next( 9 );
if (temp == t)
{
return CreateRandomCode(codeCount);
}
temp = t;
randomCode += allCharArray[t];
}
return randomCode;
}
2、数字+字母验证码的实现,代码如下:
private
string
CreateRandomCode(
int
codeCount)
{
string allChar = " 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z " ;
string [] allCharArray = allChar.Split( ' , ' );
string randomCode = "" ;
int temp = - 1 ;
Random rand = new Random();
for ( int i = 0 ; i < codeCount; i ++ )
{
if (temp != - 1 )
{
rand = new Random(i * temp * (( int )DateTime.Now.Ticks));
}
int t = rand.Next( 61 );
if (temp == t)
{
return CreateRandomCode(codeCount);
}
temp = t;
randomCode += allCharArray[t];
}
return randomCode;
}
{
string allChar = " 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z " ;
string [] allCharArray = allChar.Split( ' , ' );
string randomCode = "" ;
int temp = - 1 ;
Random rand = new Random();
for ( int i = 0 ; i < codeCount; i ++ )
{
if (temp != - 1 )
{
rand = new Random(i * temp * (( int )DateTime.Now.Ticks));
}
int t = rand.Next( 61 );
if (temp == t)
{
return CreateRandomCode(codeCount);
}
temp = t;
randomCode += allCharArray[t];
}
return randomCode;
}
3、汉字验证码的实现,代码如下:
/**/
/*
此函数在汉字编码范围内随机创建含两个元素的十六进制字节数组,每个字节数组代表一个汉字,并将
四个字节数组存储在object数组中。
参数:strlength,代表需要产生的汉字个数
*/
public static object [] CreateRegionCode( int strlength)
{
// 定义一个字符串数组储存汉字编码的组成元素
string [] rBase = new String[ 16 ] { " 0 " , " 1 " , " 2 " , " 3 " , " 4 " , " 5 " , " 6 " , " 7 " , " 8 " , " 9 " , " a " , " b " , " c " , " d " , " e " , " f " };
Random rnd = new Random();
// 定义一个object数组用来
object [] bytes = new object [strlength];
/**/
/* 每循环一次产生一个含两个元素的十六进制字节数组,并将其放入bject数组中
每个汉字有四个区位码组成
区位码第1位和区位码第2位作为字节数组第一个元素
区位码第3位和区位码第4位作为字节数组第二个元素
*/
for ( int i = 0 ; i < strlength; i ++ )
{
// 区位码第1位
int r1 = rnd.Next( 11 , 14 );
string str_r1 = rBase[r1].Trim();
// 区位码第2位
rnd = new Random(r1 * unchecked (( int )DateTime.Now.Ticks) + i); // 更换随机数发生器的种子避免产生重复值
int r2;
if (r1 == 13 )
{
r2 = rnd.Next( 0 , 7 );
}
else
{
r2 = rnd.Next( 0 , 16 );
}
string str_r2 = rBase[r2].Trim();
// 区位码第3位
rnd = new Random(r2 * unchecked (( int )DateTime.Now.Ticks) + i);
int r3 = rnd.Next( 10 , 16 );
string str_r3 = rBase[r3].Trim();
// 区位码第4位
rnd = new Random(r3 * unchecked (( int )DateTime.Now.Ticks) + i);
int r4;
if (r3 == 10 )
{
r4 = rnd.Next( 1 , 16 );
}
else if (r3 == 15 )
{
r4 = rnd.Next( 0 , 15 );
}
else
{
r4 = rnd.Next( 0 , 16 );
}
string str_r4 = rBase[r4].Trim();
// 定义两个字节变量存储产生的随机汉字区位码
byte byte1 = Convert.ToByte(str_r1 + str_r2, 16 );
byte byte2 = Convert.ToByte(str_r3 + str_r4, 16 );
// 将两个字节变量存储在字节数组中
byte [] str_r = new byte [] { byte1, byte2 };
// 将产生的一个汉字的字节数组放入object数组中
bytes.SetValue(str_r, i);
}
return bytes;
}
/*
此函数在汉字编码范围内随机创建含两个元素的十六进制字节数组,每个字节数组代表一个汉字,并将
四个字节数组存储在object数组中。
参数:strlength,代表需要产生的汉字个数
*/
public static object [] CreateRegionCode( int strlength)
{
// 定义一个字符串数组储存汉字编码的组成元素
string [] rBase = new String[ 16 ] { " 0 " , " 1 " , " 2 " , " 3 " , " 4 " , " 5 " , " 6 " , " 7 " , " 8 " , " 9 " , " a " , " b " , " c " , " d " , " e " , " f " };
Random rnd = new Random();
// 定义一个object数组用来
object [] bytes = new object [strlength];
/**/
/* 每循环一次产生一个含两个元素的十六进制字节数组,并将其放入bject数组中
每个汉字有四个区位码组成
区位码第1位和区位码第2位作为字节数组第一个元素
区位码第3位和区位码第4位作为字节数组第二个元素
*/
for ( int i = 0 ; i < strlength; i ++ )
{
// 区位码第1位
int r1 = rnd.Next( 11 , 14 );
string str_r1 = rBase[r1].Trim();
// 区位码第2位
rnd = new Random(r1 * unchecked (( int )DateTime.Now.Ticks) + i); // 更换随机数发生器的种子避免产生重复值
int r2;
if (r1 == 13 )
{
r2 = rnd.Next( 0 , 7 );
}
else
{
r2 = rnd.Next( 0 , 16 );
}
string str_r2 = rBase[r2].Trim();
// 区位码第3位
rnd = new Random(r2 * unchecked (( int )DateTime.Now.Ticks) + i);
int r3 = rnd.Next( 10 , 16 );
string str_r3 = rBase[r3].Trim();
// 区位码第4位
rnd = new Random(r3 * unchecked (( int )DateTime.Now.Ticks) + i);
int r4;
if (r3 == 10 )
{
r4 = rnd.Next( 1 , 16 );
}
else if (r3 == 15 )
{
r4 = rnd.Next( 0 , 15 );
}
else
{
r4 = rnd.Next( 0 , 16 );
}
string str_r4 = rBase[r4].Trim();
// 定义两个字节变量存储产生的随机汉字区位码
byte byte1 = Convert.ToByte(str_r1 + str_r2, 16 );
byte byte2 = Convert.ToByte(str_r3 + str_r4, 16 );
// 将两个字节变量存储在字节数组中
byte [] str_r = new byte [] { byte1, byte2 };
// 将产生的一个汉字的字节数组放入object数组中
bytes.SetValue(str_r, i);
}
return bytes;
}
三、具体实例
(实例1)
前台代码display.aspx
<!--
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--><body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Image ID="Image1" runat="server" ImageUrl="png.aspx" /><br />
<br />
<asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="Button" />
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged">
<asp:ListItem Value="3">默认</asp:ListItem>
<asp:ListItem Value="1">文字</asp:ListItem>
<asp:ListItem Value="2">数字</asp:ListItem>
<asp:ListItem Value="3">混合</asp:ListItem>
</asp:DropDownList></div>
</form>
</body>
后台代码display.cs
<!--
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http://www.CodeHighlighter.com/
--> protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
switch (DropDownList1.SelectedValue)
{
case "1":
Image1.ImageUrl = "png.aspx?aa=1";
break;
case "2":
Image1.ImageUrl = "png.aspx?aa=2";
break;
case "3":
Image1.ImageUrl = "png.aspx?aa=3";
break;
}
}
protected void Button2_Click(object sender, EventArgs e)
{
if (TextBox1.Text == Session["gif"].ToString())
Response.Write("OK,正确");
else
Response.Write("验证码不符合");
}
后台代码png.cs
<!--
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--> public partial class png : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
switch (Request.QueryString["aa"])
{
case "1":
gif = stxt(10);
Session["gif"] = stxt(10);
break;
case "2":
gif = GetRandomint(4);
Session["gif"] = GetRandomint(4);
break;
case "3":
gif = CreateRandomCode(4);
Session["gif"] = CreateRandomCode(4);
break;
default:
gif = CreateRandomCode(4);
Session["gif"] = CreateRandomCode(4);
break;
}
CreateImage(Session["gif"].ToString());
}
private String GetRandomint(int codeCount)
{
Random random = new Random();
string min = "";
string max = "";
for (int i = 0; i < codeCount; i++)
{
min +="1";
max+="9";
}
return (random.Next(Convert.ToInt32(min),Convert.ToInt32(max)).ToString());
}
/**/
/*
此函数在汉字编码范围内随机创建含两个元素的十六进制字节数组,每个字节数组代表一个汉字,并将
四个字节数组存储在object数组中。
参数:strlength,代表需要产生的汉字个数
*/
public static object[] CreateRegionCode(int strlength)
{
//定义一个字符串数组储存汉字编码的组成元素
string[] rBase = new String[16] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
Random rnd = new Random();
//定义一个object数组用来
object[] bytes = new object[strlength];
/**/
/*每循环一次产生一个含两个元素的十六进制字节数组,并将其放入bject数组中
每个汉字有四个区位码组成
区位码第1位和区位码第2位作为字节数组第一个元素
区位码第3位和区位码第4位作为字节数组第二个元素
*/
for (int i = 0; i < strlength; i++)
{
//区位码第1位
int r1 = rnd.Next(11, 14);
string str_r1 = rBase[r1].Trim();
//区位码第2位
rnd = new Random(r1 * unchecked((int)DateTime.Now.Ticks) + i);//更换随机数发生器的种子避免产生重复值
int r2;
if (r1 == 13)
{
r2 = rnd.Next(0, 7);
}
else
{
r2 = rnd.Next(0, 16);
}
string str_r2 = rBase[r2].Trim();
//区位码第3位
rnd = new Random(r2 * unchecked((int)DateTime.Now.Ticks) + i);
int r3 = rnd.Next(10, 16);
string str_r3 = rBase[r3].Trim();
//区位码第4位
rnd = new Random(r3 * unchecked((int)DateTime.Now.Ticks) + i);
int r4;
if (r3 == 10)
{
r4 = rnd.Next(1, 16);
}
else if (r3 == 15)
{
r4 = rnd.Next(0, 15);
}
else
{
r4 = rnd.Next(0, 16);
}
string str_r4 = rBase[r4].Trim();
//定义两个字节变量存储产生的随机汉字区位码
byte byte1 = Convert.ToByte(str_r1 + str_r2, 16);
byte byte2 = Convert.ToByte(str_r3 + str_r4, 16);
//将两个字节变量存储在字节数组中
byte[] str_r = new byte[] { byte1, byte2 };
//将产生的一个汉字的字节数组放入object数组中
bytes.SetValue(str_r, i);
}
return bytes;
}
private string stxt(int num)
{
Encoding gb = Encoding.GetEncoding("gb2312");
//调用函数产生10个随机中文汉字编码
object[] bytes = CreateRegionCode(num);
string strtxt = "";
//根据汉字编码的字节数组解码出中文汉字
for (int i = 0; i < num; i++)
{
strtxt += gb.GetString((byte[])Convert.ChangeType(bytes[i], typeof(byte[])));
}
return strtxt;
}
/// <summary>
/// 这个是使用字母,数字混合
/// </summary>
/// <param name="VcodeNum"></param>
/// <returns></returns>
private string CreateRandomCode(int codeCount)
{
string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z";
string[] allCharArray = allChar.Split(',');
string randomCode = "";
int temp = -1;
Random rand = new Random();
for (int i = 0; i < codeCount; i++)
{
if (temp != -1)
{
rand = new Random(i * temp * ((int)DateTime.Now.Ticks));
}
int t = rand.Next(61);
if (temp == t)
{
return CreateRandomCode(codeCount);
}
temp = t;
randomCode += allCharArray[t];
}
return randomCode;
}
private void CreateImage(string checkCode)
{
int iwidth = (int)(checkCode.Length * 20);
System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 25);
Graphics g = Graphics.FromImage(image);
Font f = new System.Drawing.Font("Arial", 10, System.Drawing.FontStyle.Bold);
Brush b = new System.Drawing.SolidBrush(Color.White);
//g.FillRectangle(new System.Drawing.SolidBrush(Color.Blue),0,0,image.Width, image.Height);
g.Clear(Color.Black);
g.DrawString(checkCode, f, b, 3, 3);
Pen blackPen = new Pen(Color.Black, 0);
Random rand = new Random();
//for (int i=0;i<5;i++)
//{
// int y = rand.Next(image.Height);
// g.DrawLine(blackPen,0,y,image.W
(实例2):20101018续加
调用页面前台代码
调用页面后台代码
生成验证码前台文件
生成验证码后台文件
验证码数字
验证码数字+字母
验证码汉字
转摘: http://www.cnblogs.com/dreamof/archive/2009/01/22/1379822.html
(实例1)


<!--
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--><body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Image ID="Image1" runat="server" ImageUrl="png.aspx" /><br />
<br />
<asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="Button" />
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged">
<asp:ListItem Value="3">默认</asp:ListItem>
<asp:ListItem Value="1">文字</asp:ListItem>
<asp:ListItem Value="2">数字</asp:ListItem>
<asp:ListItem Value="3">混合</asp:ListItem>
</asp:DropDownList></div>
</form>
</body>


<!--
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--> protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
switch (DropDownList1.SelectedValue)
{
case "1":
Image1.ImageUrl = "png.aspx?aa=1";
break;
case "2":
Image1.ImageUrl = "png.aspx?aa=2";
break;
case "3":
Image1.ImageUrl = "png.aspx?aa=3";
break;
}
}
protected void Button2_Click(object sender, EventArgs e)
{
if (TextBox1.Text == Session["gif"].ToString())
Response.Write("OK,正确");
else
Response.Write("验证码不符合");
}


<!--
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--> public partial class png : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
switch (Request.QueryString["aa"])
{
case "1":
gif = stxt(10);
Session["gif"] = stxt(10);
break;
case "2":
gif = GetRandomint(4);
Session["gif"] = GetRandomint(4);
break;
case "3":
gif = CreateRandomCode(4);
Session["gif"] = CreateRandomCode(4);
break;
default:
gif = CreateRandomCode(4);
Session["gif"] = CreateRandomCode(4);
break;
}
CreateImage(Session["gif"].ToString());
}
private String GetRandomint(int codeCount)
{
Random random = new Random();
string min = "";
string max = "";
for (int i = 0; i < codeCount; i++)
{
min +="1";
max+="9";
}
return (random.Next(Convert.ToInt32(min),Convert.ToInt32(max)).ToString());
}
/**/
/*
此函数在汉字编码范围内随机创建含两个元素的十六进制字节数组,每个字节数组代表一个汉字,并将
四个字节数组存储在object数组中。
参数:strlength,代表需要产生的汉字个数
*/
public static object[] CreateRegionCode(int strlength)
{
//定义一个字符串数组储存汉字编码的组成元素
string[] rBase = new String[16] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
Random rnd = new Random();
//定义一个object数组用来
object[] bytes = new object[strlength];
/**/
/*每循环一次产生一个含两个元素的十六进制字节数组,并将其放入bject数组中
每个汉字有四个区位码组成
区位码第1位和区位码第2位作为字节数组第一个元素
区位码第3位和区位码第4位作为字节数组第二个元素
*/
for (int i = 0; i < strlength; i++)
{
//区位码第1位
int r1 = rnd.Next(11, 14);
string str_r1 = rBase[r1].Trim();
//区位码第2位
rnd = new Random(r1 * unchecked((int)DateTime.Now.Ticks) + i);//更换随机数发生器的种子避免产生重复值
int r2;
if (r1 == 13)
{
r2 = rnd.Next(0, 7);
}
else
{
r2 = rnd.Next(0, 16);
}
string str_r2 = rBase[r2].Trim();
//区位码第3位
rnd = new Random(r2 * unchecked((int)DateTime.Now.Ticks) + i);
int r3 = rnd.Next(10, 16);
string str_r3 = rBase[r3].Trim();
//区位码第4位
rnd = new Random(r3 * unchecked((int)DateTime.Now.Ticks) + i);
int r4;
if (r3 == 10)
{
r4 = rnd.Next(1, 16);
}
else if (r3 == 15)
{
r4 = rnd.Next(0, 15);
}
else
{
r4 = rnd.Next(0, 16);
}
string str_r4 = rBase[r4].Trim();
//定义两个字节变量存储产生的随机汉字区位码
byte byte1 = Convert.ToByte(str_r1 + str_r2, 16);
byte byte2 = Convert.ToByte(str_r3 + str_r4, 16);
//将两个字节变量存储在字节数组中
byte[] str_r = new byte[] { byte1, byte2 };
//将产生的一个汉字的字节数组放入object数组中
bytes.SetValue(str_r, i);
}
return bytes;
}
private string stxt(int num)
{
Encoding gb = Encoding.GetEncoding("gb2312");
//调用函数产生10个随机中文汉字编码
object[] bytes = CreateRegionCode(num);
string strtxt = "";
//根据汉字编码的字节数组解码出中文汉字
for (int i = 0; i < num; i++)
{
strtxt += gb.GetString((byte[])Convert.ChangeType(bytes[i], typeof(byte[])));
}
return strtxt;
}
/// <summary>
/// 这个是使用字母,数字混合
/// </summary>
/// <param name="VcodeNum"></param>
/// <returns></returns>
private string CreateRandomCode(int codeCount)
{
string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z";
string[] allCharArray = allChar.Split(',');
string randomCode = "";
int temp = -1;
Random rand = new Random();
for (int i = 0; i < codeCount; i++)
{
if (temp != -1)
{
rand = new Random(i * temp * ((int)DateTime.Now.Ticks));
}
int t = rand.Next(61);
if (temp == t)
{
return CreateRandomCode(codeCount);
}
temp = t;
randomCode += allCharArray[t];
}
return randomCode;
}
private void CreateImage(string checkCode)
{
int iwidth = (int)(checkCode.Length * 20);
System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 25);
Graphics g = Graphics.FromImage(image);
Font f = new System.Drawing.Font("Arial", 10, System.Drawing.FontStyle.Bold);
Brush b = new System.Drawing.SolidBrush(Color.White);
//g.FillRectangle(new System.Drawing.SolidBrush(Color.Blue),0,0,image.Width, image.Height);
g.Clear(Color.Black);
g.DrawString(checkCode, f, b, 3, 3);
Pen blackPen = new Pen(Color.Black, 0);
Random rand = new Random();
//for (int i=0;i<5;i++)
//{
// int y = rand.Next(image.Height);
// g.DrawLine(blackPen,0,y,image.W
idth,y);
//}
System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
Response.ClearContent();
Response.ContentType = "image/Jpeg";
Response.BinaryWrite(ms.ToArray());
g.Dispose();
image.Dispose();
}
}
//}
System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
Response.ClearContent();
Response.ContentType = "image/Jpeg";
Response.BinaryWrite(ms.ToArray());
g.Dispose();
image.Dispose();
}
}
(实例2):20101018续加


<!--
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--> < script language ="Javascript" >
function Regist()
{
var url = "" ;
url = " /GZPI/Service/Registry/ViewProtocol.aspx " ;
window.open(url);
return false ;
}
function LoginClick()
{
if (document.Login.UserName.value == "" )
{
alert( " 用户名不能为空! " );
return false ;
}
document.Login.submit();
document.Login.Password.value = "" ;
return false ;
}
function f_refreshtype()
{
var Image1 = document.getElementById( " IMGCheckCode " );
if (Image1 != null )
{
Image1.src = Image1.src + " ? " ;
}
}
</ script >
< TABLE cellSpacing ="0" cellPadding ="5" width ="100%" border ="0" >
< TR >
< TD class ="fontblack" align ="right" width ="30%" > 用 户 名: </ TD >
< TD vAlign ="bottom" align ="left" width ="62%" >< input id ="Text1" style ="BORDER-RIGHT: #43a7e2 1px solid; BORDER-TOP: #43a7e2 1px solid; BACKGROUND: #fcfcfc; BORDER-LEFT: #43a7e2 1px solid; BORDER-BOTTOM: #43a7e2 1px solid"
size ="13" name ="UserName" width ="100px" >
</ TD >
</ TR >
< TR >
< TD class ="fontblack" align ="right" height ="23" > 密 码: </ TD >
< TD vAlign ="bottom" align ="left" height ="23" >< input id ="Password1" style ="BORDER-RIGHT: #43a7e2 1px solid; BORDER-TOP: #43a7e2 1px solid; BACKGROUND: #fcfcfc; BORDER-LEFT: #43a7e2 1px solid; BORDER-BOTTOM: #43a7e2 1px solid"
type ="password" size ="13" name ="Password" width ="100px" >
</ TD >
</ TR >
< TR >
< TD class ="fontblack" align ="right" height ="23" > 校 验 码: </ TD >
< TD valign ="top" align ="left" height ="23" >< FONT face ="宋体" >< INPUT id ="CheckCode" style ="BORDER-RIGHT: #43a7e2 1px solid; BORDER-TOP: #43a7e2 1px solid; BACKGROUND: #fcfcfc; BORDER-LEFT: #43a7e2 1px solid; BORDER-BOTTOM: #43a7e2 1px solid"
width ="100px" size ="13" name ="CheckCode" > </ FONT >< a style ="CURSOR: hand" onclick ="f_refreshtype()" title ="看不清楚?点击获取新的校验码!" border ="0" >< IMG id ="IMGCheckCode" src ="../GenerateCheckCode.aspx" ></ a >
</ TD >
</ TR >
< TR vAlign ="bottom" align ="center" >
< TD class ="dlbuttom" colSpan ="2" height ="23" >< input id ="Image1" style ="CURSOR: hand" onclick ="return LoginClick();" tabIndex ="3" type ="image"
height ="17" width ="55" src ="images/login.gif" border ="0" name ="OkButton" >
< input type ="image" onClick ="return Regist();" border ='0' src ='images/zuce.gif' width ='55'
height ='17' ID ="Image2" NAME ="Image2" >
</ TD >
</ TR >
</ TABLE >
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--> < script language ="Javascript" >
function Regist()
{
var url = "" ;
url = " /GZPI/Service/Registry/ViewProtocol.aspx " ;
window.open(url);
return false ;
}
function LoginClick()
{
if (document.Login.UserName.value == "" )
{
alert( " 用户名不能为空! " );
return false ;
}
document.Login.submit();
document.Login.Password.value = "" ;
return false ;
}
function f_refreshtype()
{
var Image1 = document.getElementById( " IMGCheckCode " );
if (Image1 != null )
{
Image1.src = Image1.src + " ? " ;
}
}
</ script >
< TABLE cellSpacing ="0" cellPadding ="5" width ="100%" border ="0" >
< TR >
< TD class ="fontblack" align ="right" width ="30%" > 用 户 名: </ TD >
< TD vAlign ="bottom" align ="left" width ="62%" >< input id ="Text1" style ="BORDER-RIGHT: #43a7e2 1px solid; BORDER-TOP: #43a7e2 1px solid; BACKGROUND: #fcfcfc; BORDER-LEFT: #43a7e2 1px solid; BORDER-BOTTOM: #43a7e2 1px solid"
size ="13" name ="UserName" width ="100px" >
</ TD >
</ TR >
< TR >
< TD class ="fontblack" align ="right" height ="23" > 密 码: </ TD >
< TD vAlign ="bottom" align ="left" height ="23" >< input id ="Password1" style ="BORDER-RIGHT: #43a7e2 1px solid; BORDER-TOP: #43a7e2 1px solid; BACKGROUND: #fcfcfc; BORDER-LEFT: #43a7e2 1px solid; BORDER-BOTTOM: #43a7e2 1px solid"
type ="password" size ="13" name ="Password" width ="100px" >
</ TD >
</ TR >
< TR >
< TD class ="fontblack" align ="right" height ="23" > 校 验 码: </ TD >
< TD valign ="top" align ="left" height ="23" >< FONT face ="宋体" >< INPUT id ="CheckCode" style ="BORDER-RIGHT: #43a7e2 1px solid; BORDER-TOP: #43a7e2 1px solid; BACKGROUND: #fcfcfc; BORDER-LEFT: #43a7e2 1px solid; BORDER-BOTTOM: #43a7e2 1px solid"
width ="100px" size ="13" name ="CheckCode" > </ FONT >< a style ="CURSOR: hand" onclick ="f_refreshtype()" title ="看不清楚?点击获取新的校验码!" border ="0" >< IMG id ="IMGCheckCode" src ="../GenerateCheckCode.aspx" ></ a >
</ TD >
</ TR >
< TR vAlign ="bottom" align ="center" >
< TD class ="dlbuttom" colSpan ="2" height ="23" >< input id ="Image1" style ="CURSOR: hand" onclick ="return LoginClick();" tabIndex ="3" type ="image"
height ="17" width ="55" src ="images/login.gif" border ="0" name ="OkButton" >
< input type ="image" onClick ="return Regist();" border ='0' src ='images/zuce.gif' width ='55'
height ='17' ID ="Image2" NAME ="Image2" >
</ TD >
</ TR >
</ TABLE >


<!--
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--> private void OK_Click(object sender, System.EventArgs e)
{
if (!CheckCodeSame(CheckCode.Text.Trim()))
{
System.Web.HttpContext.Current.Response.Write(" < Script Language ='JavaScript' > window.alert( ' 校验码错误!请重新输入! ' );window.close(); </ script > ");
return;
}
int userType = 1;
try
{
userType = int.Parse(UserType.Text);
}
catch
{
}
GatewayManager gateway = new GatewayManager(corpCode.Text,collegeCode.Text,chargeCode.Text,userName.Text,password.Text,userType);
gateway.Login(this);
}
/// < summary >
/// 判断输入的校验码是否正确
/// </ summary >
/// < param name ="checkCode" ></ param >
/// < returns ></ returns >
public static bool CheckCodeSame(string checkCode)
{
bool bSame = false; ;
if (HttpContext.Current.Session["CheckCode"] != null)
{
if (checkCode.ToUpper() == HttpContext.Current.Session["CheckCode"].ToString().ToUpper())
{
bSame = true;
}
}
return bSame;
}
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--> private void OK_Click(object sender, System.EventArgs e)
{
if (!CheckCodeSame(CheckCode.Text.Trim()))
{
System.Web.HttpContext.Current.Response.Write(" < Script Language ='JavaScript' > window.alert( ' 校验码错误!请重新输入! ' );window.close(); </ script > ");
return;
}
int userType = 1;
try
{
userType = int.Parse(UserType.Text);
}
catch
{
}
GatewayManager gateway = new GatewayManager(corpCode.Text,collegeCode.Text,chargeCode.Text,userName.Text,password.Text,userType);
gateway.Login(this);
}
/// < summary >
/// 判断输入的校验码是否正确
/// </ summary >
/// < param name ="checkCode" ></ param >
/// < returns ></ returns >
public static bool CheckCodeSame(string checkCode)
{
bool bSame = false; ;
if (HttpContext.Current.Session["CheckCode"] != null)
{
if (checkCode.ToUpper() == HttpContext.Current.Session["CheckCode"].ToString().ToUpper())
{
bSame = true;
}
}
return bSame;
}


<!--
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--> < HTML >
< HEAD >
< title > GenerateCheckCode </ title >
< meta name ="GENERATOR" Content ="Microsoft Visual Studio .NET 7.1" >
< meta name ="CODE_LANGUAGE" Content ="C#" >
< meta name ="vs_defaultClientScript" content ="JavaScript" >
< meta name ="vs_targetSchema" content ="http://schemas.microsoft.com/intellisense/ie5" >
</ HEAD >
< body >
< form id ="form1" runat ="server" >
< div >< FONT face ="宋体" ></ FONT >
</ div >
</ form >
</ body >
</ HTML >
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--> < HTML >
< HEAD >
< title > GenerateCheckCode </ title >
< meta name ="GENERATOR" Content ="Microsoft Visual Studio .NET 7.1" >
< meta name ="CODE_LANGUAGE" Content ="C#" >
< meta name ="vs_defaultClientScript" content ="JavaScript" >
< meta name ="vs_targetSchema" content ="http://schemas.microsoft.com/intellisense/ie5" >
</ HEAD >
< body >
< form id ="form1" runat ="server" >
< div >< FONT face ="宋体" ></ FONT >
</ div >
</ form >
</ body >
</ HTML >


<!--
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--> using System;
using System.Collections;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;
using System.Drawing.Drawing2D;
namespace GZPI.Gateway
{
/// <summary>
/// GenerateCheckCode 的摘要说明。
/// </summary>
public class GenerateCheckCode : System.Web.UI.Page
{
private void Page_Load( object sender, System.EventArgs e)
{
// 在此处放置用户代码以初始化页面
this .CreateCheckCodeImage(GenerateCheckCodes( 4 ));
}
#region Web 窗体设计器生成的代码
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base .OnInit(e);
}
/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this .Load += new System.EventHandler( this .Page_Load);
}
#endregion
private string GenerateCheckCodes( int iCount)
{
int number;
string checkCode = String.Empty;
int iSeed = DateTime.Now.Millisecond;
System.Random random = new Random(iSeed);
for ( int i = 0 ; i < iCount; i ++ )
{
number = random.Next( 10 );
checkCode += number.ToString();
}
Session[ " CheckCode " ] = checkCode;
return checkCode;
}
private void CreateCheckCodeImage( string checkCode)
{
if (checkCode == null || checkCode.Trim() == String.Empty)
return ;
int iWordWidth = 15 ;
int iImageWidth = checkCode.Length * iWordWidth;
Bitmap image = new Bitmap(iImageWidth, 20 );
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);
// 画图片的背景噪音点
for ( int i = 0 ; i < 20 ; 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);
}
// 画图片的背景噪音线
for ( int i = 0 ; i < 2 ; i ++ )
{
int x1 = 0 ;
int x2 = image.Width;
int y1 = random.Next(image.Height);
int y2 = random.Next(image.Height);
if (i == 0 )
{
g.DrawLine( new Pen(Color.Gray, 2 ), x1, y1, x2, y2);
}
}
for ( int i = 0 ; i < checkCode.Length; i ++ )
{
string Code = checkCode[i].ToString();
int xLeft = iWordWidth * (i);
random = new Random(xLeft);
int iSeed = DateTime.Now.Millisecond;
int iValue = random.Next(iSeed) % 4 ;
if (iValue == 0 )
{
Font font = new Font( " Arial " , 13 , (FontStyle.Bold | System.Drawing.FontStyle.Italic));
Rectangle rc = new Rectangle(xLeft, 0 , iWordWidth, image.Height);
LinearGradientBrush brush = new LinearGradientBrush(rc, Color.Blue, Color.Red, 1.5f , true );
g.DrawString(Code, font, brush, xLeft, 2 );
}
else if (iValue == 1 )
{
Font font = new System.Drawing.Font( " 楷体 " , 13 , (FontStyle.Bold));
Rectangle rc = new Rectangle(xLeft, 0 , iWordWidth, image.Height);
LinearGradientBrush brush = new LinearGradientBrush(rc, Color.Blue, Color.DarkRed, 1.3f , true );
g.DrawString(Code, font, brush, xLeft, 2 );
}
else if (iValue == 2 )
{
Font font = new System.Drawing.Font( " 宋体 " , 13 , (System.Drawing.FontStyle.Bold));
Rectangle rc = new Rectangle(xLeft, 0 , iWordWidth, image.Height);
LinearGradientBrush brush = new LinearGradientBrush(rc, Color.Green, Color.Blue, 1.2f , true );
g.DrawString(Code, font, brush, xLeft, 2 );
}
else if (iValue == 3 )
{
Font font = new System.Drawing.Font( " 黑体 " , 13 , (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Bold));
Rectangle rc = new Rectangle(xLeft, 0 , iWordWidth, image.Height);
LinearGradientBrush brush = new LinearGradientBrush(rc, Color.Blue, Color.Green, 1.8f , true );
g.DrawString(Code, font, brush, xLeft, 2 );
}
}
////// 画图片的前景噪音点
// for (int i = 0; i < 8; 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.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
}
}
Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/
--> using System;
using System.Collections;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;
using System.Drawing.Drawing2D;
namespace GZPI.Gateway
{
/// <summary>
/// GenerateCheckCode 的摘要说明。
/// </summary>
public class GenerateCheckCode : System.Web.UI.Page
{
private void Page_Load( object sender, System.EventArgs e)
{
// 在此处放置用户代码以初始化页面
this .CreateCheckCodeImage(GenerateCheckCodes( 4 ));
}
#region Web 窗体设计器生成的代码
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base .OnInit(e);
}
/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this .Load += new System.EventHandler( this .Page_Load);
}
#endregion
private string GenerateCheckCodes( int iCount)
{
int number;
string checkCode = String.Empty;
int iSeed = DateTime.Now.Millisecond;
System.Random random = new Random(iSeed);
for ( int i = 0 ; i < iCount; i ++ )
{
number = random.Next( 10 );
checkCode += number.ToString();
}
Session[ " CheckCode " ] = checkCode;
return checkCode;
}
private void CreateCheckCodeImage( string checkCode)
{
if (checkCode == null || checkCode.Trim() == String.Empty)
return ;
int iWordWidth = 15 ;
int iImageWidth = checkCode.Length * iWordWidth;
Bitmap image = new Bitmap(iImageWidth, 20 );
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);
// 画图片的背景噪音点
for ( int i = 0 ; i < 20 ; 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);
}
// 画图片的背景噪音线
for ( int i = 0 ; i < 2 ; i ++ )
{
int x1 = 0 ;
int x2 = image.Width;
int y1 = random.Next(image.Height);
int y2 = random.Next(image.Height);
if (i == 0 )
{
g.DrawLine( new Pen(Color.Gray, 2 ), x1, y1, x2, y2);
}
}
for ( int i = 0 ; i < checkCode.Length; i ++ )
{
string Code = checkCode[i].ToString();
int xLeft = iWordWidth * (i);
random = new Random(xLeft);
int iSeed = DateTime.Now.Millisecond;
int iValue = random.Next(iSeed) % 4 ;
if (iValue == 0 )
{
Font font = new Font( " Arial " , 13 , (FontStyle.Bold | System.Drawing.FontStyle.Italic));
Rectangle rc = new Rectangle(xLeft, 0 , iWordWidth, image.Height);
LinearGradientBrush brush = new LinearGradientBrush(rc, Color.Blue, Color.Red, 1.5f , true );
g.DrawString(Code, font, brush, xLeft, 2 );
}
else if (iValue == 1 )
{
Font font = new System.Drawing.Font( " 楷体 " , 13 , (FontStyle.Bold));
Rectangle rc = new Rectangle(xLeft, 0 , iWordWidth, image.Height);
LinearGradientBrush brush = new LinearGradientBrush(rc, Color.Blue, Color.DarkRed, 1.3f , true );
g.DrawString(Code, font, brush, xLeft, 2 );
}
else if (iValue == 2 )
{
Font font = new System.Drawing.Font( " 宋体 " , 13 , (System.Drawing.FontStyle.Bold));
Rectangle rc = new Rectangle(xLeft, 0 , iWordWidth, image.Height);
LinearGradientBrush brush = new LinearGradientBrush(rc, Color.Green, Color.Blue, 1.2f , true );
g.DrawString(Code, font, brush, xLeft, 2 );
}
else if (iValue == 3 )
{
Font font = new System.Drawing.Font( " 黑体 " , 13 , (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Bold));
Rectangle rc = new Rectangle(xLeft, 0 , iWordWidth, image.Height);
LinearGradientBrush brush = new LinearGradientBrush(rc, Color.Blue, Color.Green, 1.8f , true );
g.DrawString(Code, font, brush, xLeft, 2 );
}
}
////// 画图片的前景噪音点
// for (int i = 0; i < 8; 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.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
}
}
四、效果图展示
验证码数字

验证码数字+字母

验证码汉字

转摘: http://www.cnblogs.com/dreamof/archive/2009/01/22/1379822.html