验证码生成示例

 

Code
<%@ Page Language="C#" AutoEventWireup="true" Inherits="Kirin.Private.Page" %>
<%@ Import Namespace="System.Drawing" %>
<script runat="server">
    protected void Page_Load(object sender, EventArgs e)
    {
        string target = Request.QueryString["action"];
        string code = string.Empty;

        Ui.CancelCache();

        code = Ui.GetVerifyNum(4);


        if (target == "AdminLoginVerify" || target == "VoneVerify" || target == "ShenzhouVerify" || target == "YeepayVerify" || target == "NumberVerify")
        {
            CreateVerifyImg(target, code);
        }
    }
    /**//// <summary>
    /// 生成验证码图片
    /// </summary>
    /// <param name="sTarget">应用目标</param>
    private void CreateVerifyImg(string sTarget, string checkCode)
    { 
        if (string.IsNullOrEmpty(checkCode))
            return;
        Session[sTarget] = checkCode.Replace(" ", ""); //将字符串保存到Session中，以便需要时进行验证\'
        System.Drawing.Image imgPhoto = System.Drawing.Image.FromFile(Request.MapPath("bg.jpg"));
        int phWidth = imgPhoto.Width;
        int phHeight = imgPhoto.Height;
        System.Drawing.Bitmap image = new System.Drawing.Bitmap(phWidth, phHeight, System.Drawing.Imaging.PixelFormat.Format64bppArgb);
        image.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);


        Graphics g = Graphics.FromImage(image);
        try
        {
            //随机种子
            Random random = new Random();

            //图片背景
            g.Clear(Color.WhiteSmoke);

            //画图片的背景噪音线
           
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
            g.DrawImage(
               imgPhoto,                               // Photo Image object
               new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
               0,                                      // x-coordinate of the portion of the source image to draw. 
               0,                                      // y-coordinate of the portion of the source image to draw. 
               phWidth,                                // Width of the portion of the source image to draw. 
               phHeight,                               // Height of the portion of the source image to draw. 
               GraphicsUnit.Pixel);                    // Units of measure 


           
            System.Drawing.FontStyle newFontStyle = FontStyle.Bold | FontStyle.Italic;
            Font font = new System.Drawing.Font("黑体", random.Next(20, 33), newFontStyle);
            Font font2 = new System.Drawing.Font("黑体", random.Next(20, 33), newFontStyle);
            Font font3 = new System.Drawing.Font("黑体", random.Next(20, 33), newFontStyle);
            Font font4 = new System.Drawing.Font("黑体", random.Next(20, 33), newFontStyle);
            
            int i, j, k;
            Color color = Color.FromArgb(i = random.Next(0, 255), j = random.Next(0, 255), k = random.Next(0, 255));
            string[] arr = checkCode.Split(\' \');

            System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), color, Color.Orchid, 90, true);
            g.DrawString(arr[0], font, brush, 2, 2);
            g.DrawString(arr[1], font2, brush, 26, 6);
            g.DrawString(arr[2], font3, brush, 48, 2);
            g.DrawString(arr[3], font4, brush, 72, 6);


            //画图片的前景噪音点            
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
            Response.ClearContent();
            Response.ContentType = "image/jpeg";
            Response.BinaryWrite(ms.ToArray());
        }
        catch
        {
            g.Dispose();
            image.Dispose();
        }
    }
</script>