迷你验证码

迷你验证码

前台部分

<div>
     <table>
       <tr><td>▶请输入验证码/Yanzheng:</td><td><asp:TextBox ID="TxtYanzheng" runat="server"
                     BorderStyle="Solid" BorderColor="#943e00"></asp:TextBox></td><td><img src="checkCode.aspx" οnclick="this.src='checkCode.aspx?aaa='+new Date()" alt="图片看不清？点击重新得到验证码" /><asp:Label    ID="Label1" runat="server"></asp:Label>      

  //('checkCode.aspx )这个页子在下面有代码

            <asp:ImageButton ID="ImageButton1" runat="server" ImageUrl="~/Image/a05.gif"
                οnclick="ImageButton1_Click" /></td></tr>          
    </table>
</div>

在后台相应的事件中加载下面的代码

  protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
        {
            if (Session["CheckCode"] != null)
            {
                if (Session["CheckCode"].ToString().ToUpper() == TxtYanzheng.Text.Trim().ToString().ToUpper())
                //这样写可以不能区分大小写
                {

                    Label1.Text = "验证成功";

                }
                else
                {

                    Label1.Text = "Session is wrong";
                }
            }
        }

、、、、、、、、、、、、checkCode.aspx 、、、、、、、、、、、、、、、、、、、、

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.IO;

namespace 肯德基宅急送
{
    public partial class checkCode : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            CreateCheckCodeImage(GenerateCheckCode());//调用下面两个方法;
        }
         /// <summary>
    /// 生成验证码的随机数
    /// </summary>
    /// <returns>返回五位随机数</returns>
    private string GenerateCheckCode()
    {
        int number;
        char code;
        string checkCode = String.Empty;

        Random random = new Random();

        for (int i = 0; i < 5; i++)//可以任意设定生成验证码的位数
        {
            number = random.Next();

            if (number % 2 == 0)
                code = (char)('0' + (char)(number % 10));
            else
                code = (char)('A' + (char)(number % 26));

            checkCode += code.ToString();
        }

        Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));//写入COOKIS
        Session["CheckCode"] = checkCode;  //写入Session，可以任意选一下
        return checkCode;
    }

    /// <summary>
    /// 生成验证码图片
    /// </summary>
    /// <param name="checkCode"></param>
    private void CreateCheckCodeImage(string checkCode)
    {
        if (checkCode == null || checkCode.Trim() == String.Empty)
            return;

        Bitmap image = new Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
        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);

            //画图片的背景噪音线
            for (int i = 0; i < 25; 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);
            }

            Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
            LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
            g.DrawString(checkCode, font, brush, 2, 2);

            //画图片的前景噪音点
            for (int i = 0; i < 100; 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);

            MemoryStream ms = new MemoryStream();
            image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
            Response.ClearContent();
            Response.ContentType = "image/Gif";
            Response.BinaryWrite(ms.ToArray());
        }
        finally
        {//释放对象资源
            g.Dispose();
            image.Dispose();
        }
    }

}
    }

这就是验证码的效果：程序运行之后会到这个界面；

这个是向文本框内输入看到的验证码，然后单击下一步；

当我输入正确后，就会提示验证成功，然后验证码变成一个新的号码，我再输入时，输入的不全就单击下一步；

因为在上=面我输入的不全，所以就会提示验证失败。