C# 生成验证码 方法一
注意命名空间的引用
在项目中新建Validcode.aspx
<%@ Page Language="C#" AutoEventWireup="true" EnableViewState="false"%> <%@ Import Namespace="System.Drawing" %> <%@ Import Namespace="System.Drawing.Drawing2D" %> <%@ Import Namespace="System.Drawing.Imaging" %> <%@ Import Namespace="System.IO" %> <%@ Import Namespace="System.Text" %> <html xmlns="http://www.w3.org/1999/xhtml"> <head id="Head1" runat="server"> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>验证码</title> <!--禁止浏览器从本地缓存中调阅页面--> <meta http-equiv="pragram" content="no-cache" /> <!--必须重新加载页面--> <meta http-equiv="cache-control" content="no-cache, must-revalidate" /> <!--网页在缓存中的过期时间--> <meta http-equiv="expires" content="-1" /> <script type="text/C#" runat="server"> /* * 使用方法 * <img id="imgValidateCode" border="1" src="ValidateCode.aspx" style="cursor:hand" onclick="this.src='ValidateCode.aspx?'+Math.random()" title="点击更换验证码" /> */ static readonly char[] codeList = new char[]{'0','1','2','3','4','5','6','7','8','9'}; string sessionKey = "ValidateCode";//保存在Session中所用的KEY int codeLength = 4; //验证码字符长度 int width = 64; //验证码图片宽度 int height = 20; //验证码图片高度 int fontSize = 13; //验证码字体大小 protected void Page_Load(object sender, EventArgs e) { //获取验证码字符串 string strCode = GetValidateCode(); //将验证码字符串保存到Session中 Session[sessionKey] = strCode; //实例化图片 using (Bitmap img = new Bitmap(width, height)) { //获取画板 using (Graphics g = Graphics.FromImage(img)) { //填充底纹 // g.FillRectangle(new HatchBrush(HatchStyle.Horizontal, Color.LightYellow, Color.LightSkyBlue), 0, 0, width, height); g.Clear(Color.LightCyan); Random rand = new Random(); for (int i = 0; i < 150; i++) { int x = rand.Next(img.Width); int y = rand.Next(img.Height); g.DrawPie(new Pen(Color.LightGray, 0f), x, y, 4, 4, 1, 1); } //绘制验证码 using (Font font = new Font("Rockwell", fontSize, FontStyle.Bold | FontStyle.Italic)) { g.DrawString(strCode, font, new LinearGradientBrush(new Point(0, 0), new Point(0, 5), Color.Blue, Color.Chocolate), (width - font.SizeInPoints * codeLength) / 2, (height - font.SizeInPoints) / 3); } using (MemoryStream mStream = new MemoryStream()) { //将图片存入内存中 img.Save(mStream, ImageFormat.Gif); //将图片输出至页面 Response.ClearContent(); Response.ContentType = "image/gif"; Response.BinaryWrite(mStream.ToArray()); } } } Response.End(); } //生成验证码 public string GetValidateCode() { Random rand = new Random(); StringBuilder strBuilder = new StringBuilder(codeLength); for (int i = 0; i < codeLength; i++) { strBuilder.Append(codeList[rand.Next(0, codeList.Length)]); } return strBuilder.ToString(); } </script> </head> <body> </body> </html>
客户端
<form id="form1" runat="server"> <ul> <li><asp:TextBox ID="txt_LoginName" runat="server" class="loginuser" ></asp:TextBox></li> <li><asp:TextBox ID="txt_PassWord" runat="server" class="loginpwd" TextMode ="Password"></asp:TextBox></li> <li><label>验证码：</label><asp:TextBox ID="txt_CheckCode" runat="server" class="loginBox" style="width: 100px;" type="text" CssClass="loginCode" size="20" maxlength="15"></asp:TextBox> <img align="absmiddle" id="Img1" style="cursor: pointer;" src="Validcode.aspx?k=" alt="验证码" title="看不清,换张图片?" onclick="this.src+=Math.random();" /><label>点击图片刷新</label> </li> <li> <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="请输入登录名" ControlToValidate="txt_LoginName" Display="Dynamic" Width="74px"></asp:RequiredFieldValidator> <asp:CustomValidator ID="CustomValidator1" runat="server" ControlToValidate="txt_LoginName" Display="Dynamic" ErrorMessage="登录名不正确" onservervalidate="CustomValidator1_ServerValidate" Width="72px"></asp:CustomValidator> <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ErrorMessage="请输入密码" ControlToValidate="txt_PassWord" Display="Dynamic" Width="62px"></asp:RequiredFieldValidator> <asp:CustomValidator ID="CustomValidator2" runat="server" ControlToValidate="txt_PassWord" Display="Dynamic" ErrorMessage="密码不正确" onservervalidate="CustomValidator2_ServerValidate" Width="62px"></asp:CustomValidator> <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ErrorMessage="请输入验证码" ControlToValidate="txt_CheckCode" Display="Dynamic" Width="73px" ></asp:RequiredFieldValidator> <asp:CustomValidator ID="CustomValidator3" runat="server" ControlToValidate="txt_CheckCode" Display="Dynamic" ErrorMessage="验证码不正确" onservervalidate="CustomValidator3_ServerValidate" Width="73px"></asp:CustomValidator> </li> <li><asp:Button ID="Button1" runat="server" Text="登录" class="loginbtn" value="登录" onclick="Button1_Click" /><label><input name="" type="checkbox" value="" checked="checked" />记住密码</label><label><a href="Reg.aspx">点此注册会员</a></label></li> </ul> </form>
服务端
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Data; using System.Web.Services; public partial class Manage_Login : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } protected void Button1_Click(object sender, EventArgs e) { if (Page.IsValid) { string Password = txt_PassWord.Text.ToString().Trim().Replace("'", "''").Replace("=", ""); string UserID = txt_LoginName.Text.ToString().Trim().Replace("'", "''").Replace("=", ""); Password = func.md5(Password); string CheckCode = txt_CheckCode.Text.ToString().Trim(); UserID = UserID.Replace("'", "''").Replace("=", ""); string sql = "select * from DeviceUser where LoginName='" + UserID + "' and IsChecked = 1 "; DataTable dt = new DataTable(); dt = db.GreatDs(sql).Tables[0]; if (dt.Rows.Count > 0) { string pw1 = dt.Rows[0]["Password"].ToString(); if (Password == dt.Rows[0]["Password"].ToString()) { string ID = dt.Rows[0]["ID"].ToString(); DateTime datetime = DateTime.Now;//定义时间对象 HttpCookie DeviceUserIDcookie = System.Web.HttpContext.Current.Response.Cookies["DeviceUserID"]; DeviceUserIDcookie.Values.Add("ID",dt.Rows[0]["ID"].ToString().Trim()) ; DeviceUserIDcookie.Values.Add("LoginTime", datetime.ToString()); TimeSpan ts = new TimeSpan(1, 0, 0, 0);//cookie有效作用时间，具体查msdn DeviceUserIDcookie.Expires = datetime.Add(ts);//添加作用时间 System.Web.HttpContext.Current.Response.AppendCookie(DeviceUserIDcookie);//确定写入cookie中 Response.Redirect("index.aspx"); } } } } protected void CustomValidator1_ServerValidate(object source, ServerValidateEventArgs args) { string LoginName = txt_LoginName.Text.ToString().Trim().Replace("'", "''").Replace("=", ""); LoginName = LoginName.Replace("'", "''").Replace("=", ""); string sql = "select count(id) from DeviceUser where LoginName='" + LoginName + "' and IsChecked = 1 "; int Count = int.Parse(db.ExeSQLs(sql)); if (Count == 0) { args.IsValid = false; } else { args.IsValid = true; } } protected void CustomValidator2_ServerValidate(object source, ServerValidateEventArgs args) { string Password = txt_PassWord.Text.ToString().Trim().Replace("'", "''").Replace("=", ""); string LoginName = txt_LoginName.Text.ToString().Trim().Replace("'", "''").Replace("=", ""); Password = func.md5(Password); string CheckCode = txt_CheckCode.Text.ToString().Trim(); LoginName = LoginName.Replace("'", "''").Replace("=", ""); string sql = "select * from DeviceUser where LoginName='" + LoginName + "' "; DataTable dt = new DataTable(); dt = db.GreatDs(sql).Tables[0]; if (dt.Rows.Count > 0) { string pw1 = dt.Rows[0]["Password"].ToString(); if (Password == pw1) { args.IsValid = true; } else { args.IsValid = false; } } else { args.IsValid = true; } } protected void CustomValidator3_ServerValidate(object source, ServerValidateEventArgs args) { if (args.Value != "") { string CheckCode = args.Value; string ValidateCodeSession = ""; if (Session["ValidateCode"] != null) { ValidateCodeSession = Session["ValidateCode"].ToString(); } if (CheckCode == ValidateCodeSession) { args.IsValid = true; } else { args.IsValid = false; } } } }
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