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;
{
/// <summary>
/// image 的摘要說明。
/// </summary>
public class image : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
// 在此處放置用戶代碼以初始化頁面
this.CreateCheckCodeImage(GenerateCheckCode());
}
//產生隨機數的函數
private string GenerateCheckCode()
{
int number;
char code;
//空字符串且爲只讀屬性
string checkCode = String.Empty;
//新建一個隨機數產生器
System.Random random = new Random();
{ //隨機產生一個整數
number = random.Next();
//如果隨機數是偶數 取餘
if(number % 2 == 0)
code = (char)('0' + (char)(number % 10));
else
//如果隨機數是奇數 選擇從[A-Z]
code = (char)('A' + (char)(number % 26));
//5個字符的組合
checkCode += code.ToString();
}
//將字符串checkCode寫入Cookies並且返回字符串checkCode
Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));
}
//建立一個隨機圖形
private void CreateCheckCodeImage(string checkCode)
{
if(checkCode == null || checkCode.Trim() == String.Empty)
return;
//建立一個位圖文件 確立長寬
System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
Graphics g = Graphics.FromImage(image);
{
//生成隨機生成器
Random random = new Random();
g.Clear(Color.White);
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);
}
//把產生的隨機數以字體的形式寫入畫面
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);
for(int i=0; i<100; i++)
{
int x = random.Next(image.Width);
int y = random.Next(image.Height);
}
g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
Response.ClearContent();
Response.ContentType = "image/Gif";
Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
#region Web 窗體設計器生成的代碼
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 該調用是 ASP.NET Web 窗體設計器所必需的。
//
InitializeComponent();
base.OnInit(e);
}
/// <summary>
/// 設計器支持所需的方法 - 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
}
}