asp.net实现验证码程序
1、可以实现验证码的自动更新。
2、验证码html代码
<li class="mjiao2"><span>验 证 码：</span>
<input class="search1" type="text" id="Txt_Code2" runat="server" />
<img id="img3" src="/VerifyCodeNew.aspx" title="看不清？点击更换" alt="验证码" style="cursor: pointer;
margin-right: 20px;" onclick="this.src=this.src+'?';" width="100" height="32" />
<%-- <div id="span_code2" style="color: Red;"></div>--%>
<span id="span_code2" style="width: 100px;"></span>
</li>
3、跳转页面。这里的页面只是空页面，主要是需要后台代码
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="VerifyCodeNew.aspx.cs" Inherits="VerifyCodeNew" %>
<!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 runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>
4、
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;
public partial class VerifyCodeNew : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Initialization();
}
private void Initialization()
{
VerifyCodeNew v = new VerifyCodeNew();
v.Length = this.length;
v.FontSize = this.fontSize;
v.Chaos = this.chaos;
v.BackgroundColor = this.backgroundColor;
v.ChaosColor = this.chaosColor;
v.CodeSerial = this.codeSerial;
v.Colors = this.colors;
v.Fonts = this.fonts;
v.Padding = this.padding;
string code = v.CreateVerifyCode(); //取随机码
v.CreateImageOnPage(code, this.Context); // 输出图片
Response.Cookies.Add(new HttpCookie("CheckCodeNew", code.ToUpper()));// 使用Cookies取验证码的值
}
#region how to use the code
//aspx page
//<img id="imgVerify" src="VerifyCode.aspx?" alt="看不清？点击更换" style="cursor:pointer" onclick="this.src=this.src+'?'" /><br />
/// <summary>
/// 验证输入
/// </summary>
/// <param name="code">验证码</param>
/// <returns>是否正确</returns>
private bool Checkcode(String code)
{
if (Request.Cookies["CheckCodeNew"] == null)
return false;//cookie不存在
if (String.Compare(Request.Cookies["CheckCodeNew"].Value, code.Trim().ToUpper(), true) != 0)
return false;//对不起，验证码错误！
else
return true;//恭喜，验证码输入正确
}
#endregion
#region 验证码长度(默认6个验证码的长度)
int length = 4;
private 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 = 38;
private int FontSize
{
get { return fontSize; }
set { fontSize = value; }
}
#endregion
#region 边框补(默认1像素)
int padding = 2;
private int Padding
{
get { return padding; }
set { padding = value; }
}
#endregion
#region 是否输出燥点(默认输出)
bool chaos = true;
private 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;
Color chaosColor = Color.Black;
private Color ChaosColor
{
get { return chaosColor; }
set { chaosColor = value; }
}
#endregion
#region 自定义背景色(默认白色)
Color backgroundColor = Color.White;
private Color BackgroundColor
{
get { return backgroundColor; }
set { backgroundColor = value; }
}
#endregion
#region 自定义随机颜色数组
Color[] colors = { Color.Black };
private Color[] Colors
{
get { return colors; }
set { colors = value; }
}
#endregion
#region 自定义字体数组
string[] fonts = { "Arial"};
private 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 = "1,2,3,4,5,6,7,8,A,B,C,D,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,U,V,W,X,Y,Z";
private 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（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>
private 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
#region 生成校验码图片
private 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 * 70;
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.Regular);
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;
}
#endregion
#region 将创建好的图片输出到页面
private void CreateImageOnPage(string code, HttpContext context)
{
System.IO.MemoryStream ms = new System.IO.MemoryStream();
Bitmap image = this.CreateImageCode(code);
image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
context.Response.ClearContent();
context.Response.ContentType = "image/Jpeg";
context.Response.BinaryWrite(ms.GetBuffer());
ms.Close();
ms = null;
image.Dispose();
image = null;
}
#endregion
#region 生成随机字符码
private string CreateVerifyCode(int codeLen)
{
if (codeLen == 0)
{
codeLen = Length;
}
string[] arr = CodeSerial.Split(',');
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;
}
private string CreateVerifyCode()
{
return CreateVerifyCode(0);
}
#endregion
}