網站的驗證碼及無重新整理調用

 驗證碼CS檔案完整代碼:

使用者請根據自己使用摘取page_load()事件和其他的方法.

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;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;

public partial class UserVote_CheckCode : System.Web.UI.Page
{
    protected void Page_Load(object sender, System.EventArgs e)
    {
        CreateCheckCodeImage(GenerateCheckCode());
    }

    private string GenerateCheckCode()
    {
        int number;
        char code;
        string checkCode = String.Empty;

        Random random = new Random();

        for (int i = 0; i < 5; i++)
        {
            number = random.Next();

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

            checkCode += code.ToString();
        }

        Session["CheckCode"] = checkCode;

        return checkCode;
    }

    private void CreateCheckCodeImage(string checkCode)
    {
        if (checkCode == null || checkCode.Trim() == String.Empty)
            return;

        System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 13.5)), 22);
        Graphics g = Graphics.FromImage(image);

        try
        {
            //產生隨機產生器
            Random random = new Random();

            //清空圖片背景色
            g.Clear(Color.White);

            //畫圖片的背景雜音線
            for (int i = 0; i < 16; 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", 14, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
            System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
            g.DrawString(checkCode, font, brush, 1, 0);

            //畫圖片的前景噪音點
            for (int i = 0; i < 100; i++)
            {
                int x = random.Next(image.Width);
                int y = random.Next(image.Height);

                //Bitmap.SetPixel 方法 ：設定 Bitmap 對象中指定像素的顏色。
                image.SetPixel(x, y, Color.FromArgb(random.Next()));
            }

            //畫圖片的邊框線
            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.ContentType = "image/Gif";
            Response.BinaryWrite(ms.ToArray());
        }
        finally
        {
            g.Dispose();
            image.Dispose();
        }
    }
}

建立一個新的ASPX頁面,調用剛才的ASPX頁(驗證碼的頁面什麼都沒有)

 <img id="imgVerify" src="CommonControl/CheckCode.aspx" alt="看不清？點擊更換" onclick="this.src=this.src+'?'" />

其中CommonControl/CheckCode.aspx是我調用的驗證碼也面的名字,onclick="this.src=this.src+'?'"代表圖片地址重新導向,這樣不會引起整個頁面重新整理才會改變驗證碼!

在第一段代碼中定義了一個SESSION,用來傳驗證碼,你可以取到該值進行判斷哦:)