Login 图片验证码 生成一个图片验证控件

第一种是：可以产生图片的图片验证码

1、类库文件

<ccid_nobr>

<ccid_code>using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Web.UI.WebControls; using System.ComponentModel; using System.Web.UI; namespace AuthCode { [Description("图形验证码控件"), ToolboxData("<{0}:ImageAuthCode runat=server> </{0}:ImageAuthCode>")] public class ImageAuthCode:Image { [Description("图形验证码产生网页地址"), DefaultValue("")] public string ValidateCodeUrl { get; set; } protected override void Render(HtmlTextWriter writer) { string sUrl, sScript; sUrl = this.ValidateCodeUrl; if (string.IsNullOrEmpty(sUrl)) { sUrl = "~/AuthCode.ashx"; } if (this.BorderWidth == Unit.Empty) { this.BorderWidth = Unit.Pixel(1); } if (this.AlternateText == string.Empty) { this.AlternateText = "图形验证码"; } this.ToolTip = "鼠标单击可以产生新的验证码"; this.ImageUrl = sUrl; if (!this.DesignMode) { sScript = String.Format("this.src='{0}? flag='+Math.random();", this.Page.ResolveClientUrl(sUrl)); this.Attributes["onclick"] = sScript; } this.Style[HtmlTextWriterStyle.Cursor] = "pointer"; base.Render(writer); } public bool ValidateCode(string Code) { if (this.Page.Session["CheckCode"] == null) return false; if (this.Page.Session["CheckCode"].ToString() == Code) { return true; } else { return false; } } } }

2、ashx文件如下

<ccid_nobr>

<ccid_code>using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Drawing; using System.Web.SessionState; namespace MyAuthCode { /// <summary> /// Summary description for AuthCode /// </summary> public class AuthCode : IHttpHandler, IRequiresSessionState { 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 * 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("Verdana", 12, (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, 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); System.IO.MemoryStream ms = new System.IO.MemoryStream(); image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif); HttpContext.Current.Response.ClearContent(); HttpContext.Current.Response.ContentType = "image/Gif"; HttpContext.Current.Response.BinaryWrite(ms.ToArray()); } finally { g.Dispose(); image.Dispose(); } } private string GenerateCheckCode() { int number; char code; string checkCode = String.Empty; System.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(); } HttpContext.Current.Session.Add("CheckCode", checkCode.Trim().ToLower()); //将 checkCode 写入 Session 中 return checkCode; } public void ProcessRequest(HttpContext context) { this.CreateCheckCodeImage(GenerateCheckCode()); } public bool IsReusable { get { return false; } } } }

3、增加工具箱和拖到页面使用

<ccid_nobr>

<ccid_code><%@ Register assembly="AuthCode" namespace="AuthCode" tagprefix="cc1" %> <cc1:ImageAuthCode ID="ImageAuthCode1" runat="server" Height="20px" Width="100px"/>

4、验证方法

<ccid_nobr>

<ccid_code>ImageAuthCode1.ValidateCode(TextBox1.Text.Trim().ToString()) 结果返回true或者false.

5、最重要的一点修改Web.Config配置文件

<ccid_nobr>

<ccid_code><location path="AuthCode.ashx"> <system.web> <authorization> <allow users="*"/> </authorization> </system.web> </location>

如果不增加此段代码，当你的时，图片验证码是无法显示的