iis6 简单随机码例子
解决 随机码 在win2003 iis6 的服务器不能显示
显示随机码 ：
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="login.aspx.cs" Inherits="TestDemo.login" %> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title></title> <script language="javascript" type="text/javascript"> function ChangeCode() { var date = new Date(); var myImg = document.getElementById("ImageCheck"); var GUID = document.getElementById("lblGUID"); if(GUID != null) { if(GUID.innerHTML != "" && GUID.innerHTML != null) { myImg.src = "Vcode.aspx?GUID="+GUID.innerHTML+"&flag="+date.getMilliseconds() } } return false; } </script> </head> <body> <form id="form1" runat="server" method="post" > <div> <asp:Label ID="lblGUID" runat="server" Style="display: none"></asp:Label> <a id="A2" href="" onclick="ChangeCode();return false;"> <asp:Image ID="ImageCheck" runat="server" ImageUrl="../Vcode.aspx?GUID=GUID" ImageAlign="AbsMiddle" ToolTip="看不清，换一个"></asp:Image></a> </div> </form> </body> </html>
//载入事件
protected void Page_Load(object sender, EventArgs e) { if (!this.IsPostBack) { this.ViewState["GUID"] = System.Guid.NewGuid().ToString(); this.lblGUID.Text = this.ViewState["GUID"].ToString(); } }
//随机码页面
空页面
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Vcode.aspx.cs" Inherits="TestDemo.Vcode" %>
后台
using System; using System.Collections.Generic; using System.Drawing; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; namespace TestDemo { public partial class Vcode : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { string checkCode = GetRandomCode(4); Session["CheckCode"] = checkCode; SetPageNoCache(); CreateImage(checkCode); } /// <summary> /// 设置页面不被缓存 /// </summary> private void SetPageNoCache() { Response.Buffer = true; Response.ExpiresAbsolute = System.DateTime.Now.AddSeconds(-1); Response.Expires = 0; Response.CacheControl = "no-cache"; Response.AppendHeader("Pragma", "No-Cache"); } private string CreateRandomCode(int codeCount) { string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,i,J,K,M,N,P,Q,R,S,T,U,W,X,Y,Z"; string[] allCharArray = allChar.Split(','); string randomCode = ""; int temp = -1; Random rand = new Random(); for (int i = 0; i < codeCount; i++) { if (temp != -1) { rand = new Random(i * temp * ((int)DateTime.Now.Ticks)); } int t = rand.Next(35); if (temp == t) { return CreateRandomCode(codeCount);//性能问题 } temp = t; randomCode += allCharArray[t]; } return randomCode; } private string GetRandomCode(int CodeCount) { string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,i,J,K,M,N,P,Q,R,S,T,U,W,X,Y,Z"; string[] allCharArray = allChar.Split(','); string RandomCode = ""; int temp = -1; Random rand = new Random(); for (int i = 0; i < CodeCount; i++) { if (temp != -1) { rand = new Random(temp * i * ((int)DateTime.Now.Ticks)); } int t = rand.Next(33); while (temp == t) { t = rand.Next(33); } temp = t; RandomCode += allCharArray[t]; } return RandomCode; } private void CreateImage(string checkCode) { int iwidth = (int)(checkCode.Length * 14); System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 20); Graphics g = Graphics.FromImage(image); Font f = new System.Drawing.Font("Arial ", 10);//, System.Drawing.FontStyle.Bold); Brush b = new System.Drawing.SolidBrush(Color.Black); Brush r = new System.Drawing.SolidBrush(Color.FromArgb(166, 8, 8)); //g.FillRectangle(new System.Drawing.SolidBrush(Color.Blue),0,0,image.Width, image.Height); // g.Clear(Color.AliceBlue);//背景色 g.Clear(System.Drawing.ColorTranslator.FromHtml("#99C1CB"));//背景色 char[] ch = checkCode.ToCharArray(); for (int i = 0; i < ch.Length; i++) { if (ch[i] >= '0' && ch[i] <= '9') { //数字用红色显示 g.DrawString(ch[i].ToString(), f, r, 3 + (i * 12), 3); } else { //字母用黑色显示 g.DrawString(ch[i].ToString(), f, b, 3 + (i * 12), 3); } } //for循环用来生成一些随机的水平线 // Pen blackPen = new Pen(Color.Black, 0); // Random rand = new Random(); // for (int i=0;i<5;i++) // { // int y = rand.Next(image.Height); // g.DrawLine(blackPen,0,y,image.Width,y); // } System.IO.MemoryStream ms = new System.IO.MemoryStream(); image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); //history back 不重复 Response.Cache.SetNoStore();//这一句 Response.ClearContent(); Response.ContentType = "image/Jpeg"; Response.BinaryWrite(ms.ToArray()); g.Dispose(); image.Dispose(); } } }
