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// RandomImage.aspx.cs验证码生成页面后台
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.IO; using System.Drawing.Imaging; using System.Drawing.Drawing2D; using System.Drawing.Printing; public partial class RandomImage : System.Web.UI.Page
{ protected void Page_Load(object sender, EventArgs e) { CreateCheckCodeImage(GenerateCheckCode());
} /// <summary> /// 生成随机校验码字符串 /// </summary> /// <returns>生成的随机校验码字符串</returns> private string GenerateCheckCode() { int number; string strCode = string.Empty; //随机数种子
Random random = new Random(); for (int i = 0; i < 4; i++) //校验码长度为4
{ //随机的整数 number = random.Next(); //字符从0-9,A-Z中随机产生,对应的ASCII码分别为
//48-57,65-90 number = number % 36; if (number < 10) { number += 48; } else { number += 55; } strCode += ((char)number).ToString(); } //在session中保存校验码
Session["CheckCode"] = strCode; return strCode; } /// <summary>
/// 根据校验码输出图片 /// </summary> /// <param name="checkCode">产生的随机校验码</param> private void CreateCheckCodeImage(string checkCode) { //若校验码为空,则直接返回 if (checkCode == null || checkCode.Trim() == String.Empty) { return; } //根据校验码的长度确定输出图片的长度 System.Drawing.Bitmap image = new System.Drawing.Bitmap(55, 20);//(int)Math.Ceiling(Convert.ToDouble(checkCode.Length * 15)) //创建Graphics对象 Graphics g = Graphics.FromImage(image); try { //生成随机数种子 Random random = new Random(); //清空图片背景色 g.Clear(Color.White); //画图片的背景噪音线 10条 //--------------------------------------------------- for (int i = 0; i < 10; i++) { //噪音线起点坐标(x1,y1),终点坐标(x2,y2) int x1 = random.Next(image.Width); int x2 = random.Next(image.Width); int y1 = random.Next(image.Height); int y2 = random.Next(image.Height); //用银色画出噪音线
g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2); } //--------------------------------------------------- //Brush b = Brushes.Silver; //g.FillRectangle(b, 0, 0, image.Width, image.Height); //---------------------以上两种任选其一------------------------------ //输出图片中校验码的字体: 12号Arial,粗斜体 Font font = new Font("Arial",12,(FontStyle.Bold | FontStyle.Italic)); //线性渐变画刷
LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),Color.Blue,Color.Purple,1.2f,true); g.DrawString(checkCode, font, brush, 2, 2); //画图片的前景噪音点 50个
for (int i = 0; i < 50; 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.Peru),0,0,image.Width - 1,image.Height - 1); //创建内存流用于输出图片
using (MemoryStream ms = new MemoryStream()) { //图片格式指定为png image.Save(ms, ImageFormat.Jpeg); //清除缓冲区流中的所有输出 Response.ClearContent(); //输出流的HTTP MIME类型设置为"image/Png" Response.ContentType = "image/Jpeg"; //输出图片的二进制流 Response.BinaryWrite(ms.ToArray()); } } finally { //释放Bitmap对象和Graphics对象 g.Dispose(); image.Dispose(); } } } //-------------------------------------------------------------------- //测试页面 dafault.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" Debug="true" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www./TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www./1999/xhtml">
<head runat="server"> <title>无标题页</title> </head> <body> <form id="form1" runat="server"> <div> <asp:TextBox ID="txtCode" runat="server"></asp:TextBox> <asp:Image ID="Image1" runat="server" ImageUrl="~/RandomImage.aspx" /> <asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Button" /><hr /> <asp:Label ID="lblMsg" runat="server" Text="Label"></asp:Label> </div> </form> </body> </html> //---------------------------------------------------- //测试页面后台
using System;
using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; public partial class _Default : System.Web.UI.Page
{ protected void Page_Load(object sender, EventArgs e) { }
protected void Button1_Click(object sender, EventArgs e) { if (string.Compare(Session["CheckCode"].ToString(), this.txtCode.Text, true) != 0) { lblMsg.Text = "验证码错误,请输入正确的验证码。"; return; } else { lblMsg.Text = "成功"; } } } 本文来自CSDN博客,转载请标明出处:http://blog.csdn.net/dhping/archive/2009/06/11/4261761.aspx |
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