///<Author>
///圖形驗證碼產生頁面
///Abraxas@163.com
///引用方式:<asp:Image ImageUrl="AbraxasValCode.aspx?n=6"></asp:Image>(n為驗證碼位元)
///</Author>
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.IO;
namespace Abraxas
{
/// <summary>
/// AbraxasValCode 的摘要說明。
/// </summary>
public class AbraxasValCode : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
// 在此處放置使用者代碼以初始化頁面
string valCode = RandomString(int.Parse(Request.QueryString["n"]));
Session.Add("ValCode", valCode);
DrawImage(valCode);
}
//產生隨機字串
private string RandomString(int bit)
{
string chars = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z" ;
string[] charArray = chars.Split(',');
string result = "";
Random rdm = new Random();
for (int i = 0; i < bit; i++)
{
result += charArray[rdm.Next(36)];
}
return result;
}
//將驗證碼繪成圖形
private void DrawImage(string valCode)
{
//產生位元影像
Bitmap bmp = new Bitmap(valCode.Length*16, 25);
Graphics g = Graphics.FromImage(bmp);
try
{
g.Clear(Color.White);
//定義顏色和字型集
Color[] c = {Color.Red, Color.Green, Color.Navy, Color.DarkCyan, Color.Blue, Color.Purple};
string[] fonts = {"Microsoft Sans Serif", "Times New Roman", "Lucida Console", "Arial", "Verdana"};
//繪製背景網格
Pen p = new Pen(Color.LightGray, 0);
int y = 5;
do
{
g.DrawLine(p, 0, y, bmp.Width, y);
y += 5;
}
while(y < bmp.Height);
int x = 5;
do
{
g.DrawLine(p, x, 0, x, bmp.Height);
x += 5;
}
while(x < bmp.Width);
//輸出驗證碼字元
Random rdm = new Random();
for (int i = 0; i < valCode.Length; i++)
{
int ci = rdm.Next(c.Length);
int fi = rdm.Next(fonts.Length);
Font f = new Font(fonts[fi], 12, FontStyle.Bold);
Brush b = new SolidBrush(c[ci]);
g.DrawString(valCode.Substring(i,1), f, b, 5+(i*14), rdm.Next(2,5));
}
//繪製邊框
g.DrawRectangle(p, 0, 0, bmp.Width-1, bmp.Height-1);
//輸出到頁面
MemoryStream ms = new MemoryStream();
bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
Response.Cache.SetNoStore();
Response.ClearContent();
Response.ContentType = "image/Gif";
Response.BinaryWrite(ms.ToArray());
Response.End();
}
finally
{
g.Dispose();
bmp.Dispose();
}
}
#region Web Form設計器產生的程式碼
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 該調用是 ASP.NET Web Form設計器所必需的。
//
InitializeComponent();
base.OnInit(e);
}
/// <summary>
/// 設計器支援所需的方法 - 不要使用代碼編輯器修改
/// 此方法的內容。
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}