第一步生成验证码 新增一个ValidateCode.aspx页面 在ValidateCode.aspx.cs的代码如下 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; using System.Drawing.Imaging; public partial class ValidateCode : System.Web.UI.Page { //该页面将用于生成验证码图片 protected void Page_Load(object sender, EventArgs e) { //调用函数将验证码生成图片 this.CreateCheckCodeImage(GenerateCheckCode()); } private string GenerateCheckCode() { //产生五位的随机字符串 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(); } //Response.Cookies.Add(new HttpCookie("CheckCode", checkCode)); Session["CheckCode"] = checkCode;//用于客户端校验码比较 return checkCode; } private void CreateCheckCodeImage(string checkCode) { //将验证码生成图片显示 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("Arial", 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); Response.ClearContent(); Response.ContentType = "image/Gif"; Response.BinaryWrite(ms.ToArray()); } finally { g.Dispose(); image.Dispose(); } } }
第二步测试验证码 建立Test.aspx form id="form1" runat="server"> <div> <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox> <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" /><br /> <asp:Image ID="Image1" runat="server" ImageUrl="~/ValidateCode.aspx" />//该图片将用于显示验证码 </div> </form> Test.aspx.cs代码 protected void Page_Load(object sender, EventArgs e) { } protected void Button1_Click(object sender, EventArgs e) { if (this.TextBox1.Text.ToString().Trim() == Session["CheckCode"].ToString()) { Response.Write("<script lauguage=''''javascript''''>alert(''''验证成功'''');</script>"); } }
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