.NET中的无刷新验证码的开发(完整代码)

<%@ 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('输入的验证码错误!');</script>");
                litErrorMsg.Text = "输入的验证码错误!";
            }
            else
            {
                //Response.Write("<script>javascript:alert('输入的验证码正确!');</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为默认生成的代码

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
        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(',');

        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
}

原文地址:https://www.cnblogs.com/phone/p/1826175.html