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Development of non-refresh verification code in ASP.NET

高洛峰

Jan 13, 2017 pm 02:13 PM

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Login.aspx.cs" Inherits="Login" %> 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml" > 
<head id="Head1" runat="server"> 
<title>无标题页</title> 
<script type="text/javascript"> 
function DoFresh() { 
document.getElementById("Image1").src = "VerifyCode.aspx"; 
} 
</script> 
</head> 
<body> 
<form id="form1" runat="server"> 
<div> 
<table> 
<tr> 
<td> 
验证码：<asp:TextBox ID="txtValidateCode" runat="server"></asp:TextBox> 
</td> 
<td> 
<asp:Image ID="Image1" runat="server" /> 
<a href="javascript:DoFresh();">看不清?</a> 
</td> 
</tr> 
<tr> 
<td align="center" colspan="2"> 
<br /> 
<asp:Literal ID="litErrorMsg" runat="server"></asp:Literal> 
<asp:Button ID="btnSubmit" runat="server" Text="确定" onclick="btnSubmit_Click" /> 
</td> 
</tr> 
</table> 
</div> 
</form> 
</body> 
</html> 


using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 

public partial class Login : System.Web.UI.Page 
{ 
protected void Page_Load(object sender, EventArgs e) 
{ 
if (!Page.IsPostBack) 
{ 
Image1.ImageUrl = "VerifyCode.aspx"; 
} 
} 
protected void btnSubmit_Click(object sender, EventArgs e) 
{ 
if (Session["ValidateCode"] != null) 
{ 
string outputValidateCode = Session["ValidateCode"] as string; 
string inputValidateCode = txtValidateCode.Text.Trim(); 
if (string.Compare(outputValidateCode, inputValidateCode, true) != 0) 
{ 
//Response.Write("<script>javascript:alert(&#39;输入的验证码错误！&#39;);</script>"); 
litErrorMsg.Text = "输入的验证码错误！"; 
} 
else 
{ 
//Response.Write("<script>javascript:alert(&#39;输入的验证码正确！&#39;);</script>"); 
litErrorMsg.Text = "输入的验证码正确！"; 
} 
} 
} 
#region 调用下面的方法实现客户端保存Cookie验证模式 
private void ValidateMethod() 
{ 
if (Request.Cookies["CheckCode"] == null) 
{ 
litErrorMsg.Text = "您的浏览器设置已被禁用 Cookies，您必须设置浏览器允许使用 Cookies 选项后才能使用本系统。"; 
litErrorMsg.Visible = true; 
return; 
} 
if (String.Compare(Request.Cookies["CheckCode"].Value, TextBox1.Text.ToString().Trim(), true) != 0) 
{ 
litErrorMsg.Text = "<font color=red>对不起，验证码错误！</font>"; 
litErrorMsg.Visible = true; 
return; 
} 
else 
{ 
litErrorMsg.Text = "<font color=green>恭喜，验证码输入正确！</font>"; 
litErrorMsg.Visible = true; 
} 
} 
#endregion 
}

//VerifyCode.aspx is the code generated by default

using System; 
using System.Data; 
using System.Configuration; 
using System.Collections; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 
using System.Drawing; 
using System.Drawing.Imaging; 
using System.Drawing.Drawing2D; 
using System.IO; 
public partial class VerifyCode : System.Web.UI.Page 
{ 
protected void Page_Load(object sender, EventArgs e) 
{ 
//GenerateValidateCode(); 
GenerateVerifyImage(4);//GenerateVerifyImage(int length) 
} 

#region 【无刷新仿google波形扭曲彩色】验证码样式0___GenerateValidateCode() 
private void GenerateValidateCode() 
{ 
this.Length = this.length; 
this.FontSize = this.fontSize; 
this.Chaos = this.chaos; 
this.BackgroundColor = this.backgroundColor; 
this.ChaosColor = this.chaosColor; 
this.CodeSerial = this.codeSerial; 
this.Colors = this.colors; 
this.Fonts = this.fonts; 
this.Padding = this.padding; 
string VNum = this.CreateVerifyCode(); //取随机码 
Session["ValidateCode"] = VNum.ToUpper();//取得验证码，以便后来验证 
this.CreateImageOnPage(VNum, this.Context); // 输出图片 
//Cookie验证模式， 使用Cookies取验证码的值 
//Response.Cookies.Add(new HttpCookie("CheckCode", code.ToUpper())); 
} 
#endregion 
#region 验证码长度(默认4个验证码的长度) 
int length = 4; 
public int Length 
{ 
get { return length; } 
set { length = value; } 
} 
#endregion 
#region 验证码字体大小(为了显示扭曲效果，默认40像素，可以自行修改) 
int fontSize = 22; 
public int FontSize 
{ 
get { return fontSize; } 
set { fontSize = value; } 
} 
#endregion 
#region 边框补(默认1像素) 
int padding = 2; 
public int Padding 
{ 
get { return padding; } 
set { padding = value; } 
} 
#endregion 
#region 是否输出燥点(默认不输出) 
bool chaos = true; 
public bool Chaos 
{ 
get { return chaos; } 
set { chaos = value; } 
} 
#endregion 
#region 输出燥点的颜色(默认灰色) 
Color chaosColor = Color.LightGray; 
public Color ChaosColor 
{ 
get { return chaosColor; } 
set { chaosColor = value; } 
} 
#endregion 
#region 自定义背景色(默认白色) 
Color backgroundColor = Color.White; 
public Color BackgroundColor 
{ 
get { return backgroundColor; } 
set { backgroundColor = value; } 
} 
#endregion 
#region 自定义随机颜色数组 
Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple }; 
public Color[] Colors 
{ 
get { return colors; } 
set { colors = value; } 
} 
#endregion 
#region 自定义字体数组 
string[] fonts = { "Arial", "Georgia" }; 
public string[] Fonts 
{ 
get { return fonts; } 
set { fonts = value; } 
} 
#endregion 
#region 自定义随机码字符串序列(使用逗号分隔) 
string codeSerial = "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,v,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"; 
public string CodeSerial 
{ 
get { return codeSerial; } 
set { codeSerial = value; } 
} 
#endregion 
#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 
/// </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 Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase) 
{ 
Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height); 
// 将位图背景填充为白色 
System.Drawing.Graphics graph = Graphics.FromImage(destBmp); 
graph.FillRectangle(new SolidBrush(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 
#region 生成校验码图片 
public Bitmap CreateImageCode(string code) 
{ 
int fSize = FontSize; 
int fWidth = fSize + Padding; 
int imageWidth = (int)(code.Length * fWidth) + 4 + Padding * 2; 
int imageHeight = fSize * 2 + Padding; 
System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth, imageHeight); 
Graphics g = Graphics.FromImage(image); 
g.Clear(BackgroundColor); 
Random rand = new Random(); 
//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 = rand.Next(image.Width); 
int y = rand.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 = rand.Next(Colors.Length - 1); 
findex = rand.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, 4, 4); 
return image; 
} 
#endregion 
#region 将创建好的图片输出到页面 
public void CreateImageOnPage(string code, HttpContext context) 
{ 
Response.BufferOutput = true; //特别注意 
Response.Cache.SetExpires(DateTime.Now.AddMilliseconds(-1));//特别注意 
Response.Cache.SetCacheability(HttpCacheability.NoCache);//特别注意 
Response.AppendHeader("Pragma", "No-Cache"); //特别注意 
MemoryStream ms = new MemoryStream(); 
Bitmap image = this.CreateImageCode(code); 
image.Save(ms, ImageFormat.Jpeg); 
Response.ClearContent(); 
Response.ContentType = "image/JPEG"; 
Response.BinaryWrite(ms.ToArray()); 
Response.End(); 
ms.Close(); 
ms = null; 
image.Dispose(); 
image = null; 
} 
#endregion 
#region 生成随机字符码 
public string CreateVerifyCode(int codeLen) 
{ 
if (codeLen == 0) 
{ 
codeLen = Length; 
} 
string[] arr = CodeSerial.Split(&#39;,&#39;); 
string code = ""; 
int randValue = -1; 
Random rand = new Random(unchecked((int)DateTime.Now.Ticks)); 
for (int i = 0; i < codeLen; i++) 
{ 
randValue = rand.Next(0, arr.Length - 1); 
code += arr[randValue]; 
} 
return code; 
} 
public string CreateVerifyCode() 
{ 
return CreateVerifyCode(0); 
} 
#endregion 
#region 另一种验证码样式 GenerateVerifyImage(int length) 
/// <summary> 
/// 将创建好的图片输出到页面 
/// </summary> 
public void GenerateVerifyImage(int nLen) 
{ 
string validateCode = "";//生成的验证码 
int nBmpWidth = GetImagewidth(nLen); 
int nBmpHeight = GetImageHeight(); 
System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(nBmpWidth, nBmpHeight); 
//对图像进行弯曲 
TwistImage(bmp, true, 12, 2); 

// 1. 生成随机背景颜色 
int nRed, nGreen, nBlue; // 背景的三元色 
System.Random rd = new Random((int)System.DateTime.Now.Ticks); 
nRed = rd.Next(255) % 128 + 128; 
nGreen = rd.Next(255) % 128 + 128; 
nBlue = rd.Next(255) % 128 + 128; 
// 2. 填充位图背景 
System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage(bmp); 
graph.FillRectangle(new SolidBrush(System.Drawing.Color.FromArgb(nRed, nGreen, nBlue)) 
, 0 
, 0 
, nBmpWidth 
, nBmpHeight); 

// 3. 绘制干扰线条，采用比背景略深一些的颜色 
int nLines = 3; 
System.Drawing.Pen pen = new System.Drawing.Pen(System.Drawing.Color.FromArgb(nRed - 17, nGreen - 17, nBlue - 17), 2); 
for (int a = 0; a < nLines; a++) 
{ 
int x1 = rd.Next() % nBmpWidth; 
int y1 = rd.Next() % nBmpHeight; 
int x2 = rd.Next() % nBmpWidth; 
int y2 = rd.Next() % nBmpHeight; 
graph.DrawLine(pen, x1, y1, x2, y2); 
} 
// 采用的字符集，可以随即拓展，并可以控制字符出现的几率 
string strCode = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; 
// 4. 循环取得字符，并绘制 
for (int i = 0; i < nLen; i++) 
{ 
int x = (i * 13 + rd.Next(3)); 
int y = rd.Next(4) + 1; 
// 确定字体 
System.Drawing.Font font = new System.Drawing.Font("Courier New",//文字字体类型 
12 + rd.Next() % 4,//文字字体大小 
System.Drawing.FontStyle.Bold);//文字字体样式 
char c = strCode[rd.Next(strCode.Length)]; // 随机获取字符 
validateCode += c.ToString(); 
// 绘制字符 
graph.DrawString(c.ToString(), 
font, 
new SolidBrush(System.Drawing.Color.FromArgb(nRed - 60 + y * 3, nGreen - 60 + y * 3, nBlue - 40 + y * 3)), 
x, 
y); 
} 
Session["ValidateCode"] = validateCode; 
//对图像进行弯曲 
TwistImage(bmp, true, 4, 4); 
Response.BufferOutput = true; //特别注意 
Response.Cache.SetExpires(DateTime.Now.AddMilliseconds(-1));//特别注意 
Response.Cache.SetCacheability(HttpCacheability.NoCache);//特别注意 
Response.AppendHeader("Pragma", "No-Cache"); //特别注意 
// 5. 输出字节流 
MemoryStream bstream = new MemoryStream(); 
bmp.Save(bstream, ImageFormat.Jpeg); 
Response.ClearContent(); 
Response.ContentType = "image/JPEG"; 
Response.BinaryWrite(bstream.ToArray()); 
Response.End(); 
bstream.Close(); 
bstream = null; 
bmp.Dispose(); 
bmp = null; 
graph.Dispose(); 
} 
///<summary> 
///得到验证码图片的宽度 
///</summary> 
///<paramname="validateNumLength">验证码的长度</param> 
///<returns></returns> 
public static int GetImagewidth(int validateNumLength) 
{ 
return (int)(13 * validateNumLength + 5); 
} 
///<summary> 
///得到验证码的高度 
///</summary> 
///<returns></returns> 
public static int GetImageHeight() 
{ 
return 25; 
} 
#endregion 
}

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