.net实现验证码功能
转自：http://www.cnblogs.com/dreamof/archive/2009/01/22/1379822.html
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；
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：
(2)使用随机组合方式，代码如下：
2、数字+字母验证码的实现，代码如下：
3、汉字验证码的实现，代码如下：
/**/ /* 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)
<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>
protectedvoid 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; } } protectedvoid 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"); }
publicpartialclass png : System.Web.UI.Page { protectedvoid 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 */ publicstaticobject[] 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 =newobject[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); } elseif (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 =newbyte[] { 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; } privatestring 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> privatestring 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; }
privatevoid 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+字母
验证码汉字
<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>
protectedvoid 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; } } protectedvoid 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"); }
publicpartialclass png : System.Web.UI.Page { protectedvoid 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 */ publicstaticobject[] 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 =newobject[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); } elseif (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 =newbyte[] { 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; } privatestring 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> privatestring 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; }
privatevoid 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
调用页面前台代码
<
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
>
调用页面后台代码
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; }
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; }
生成验证码前台文件
<
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
>
生成验证码后台文件
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(); } } } }
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