本文介紹的ASP.NET產生驗證碼代碼，來源於eping的部落格，挺簡單，內容細節都說得很清楚，實現方法下文
using System;
using System.Data;
using System.Configuration;
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; //添加引用 public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
//調用自訂方法繪製驗證碼
CreateCheckCodeImage(GenerateCheckCode());
} private string GenerateCheckCode()
{
//建立整型型變數
int number;
//建立字元型變數
char code;
//建立字串變數並初始化為空白
string checkCode = String.Empty;
//建立Random對象
Random random = new Random();
//使用For迴圈產生4個數字
for (int i = 0; i < 4; i++)
{
//產生一個隨機數
number = random.Next();
//將數字轉換成為字元型
code = (char)('0' + (char)(number % 10)); checkCode += code.ToString();
}
//將產生的隨機數添加到Cookies中
Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));
//返回字串
return checkCode;
} private void CreateCheckCodeImage(string checkCode)
{
//判斷字串不等於空和null
if (checkCode == null || checkCode.Trim() == String.Empty)
return;
//建立一個位元影像對象
System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
//建立Graphics對象
Graphics g = Graphics.FromImage(image); try
{
//產生隨機產生器
Random random = new Random(); //清空圖片背景色
g.Clear(Color.White); //畫圖片的背景雜音線
for (int i = 0; i < 2; 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.Black), x1, y1, x2, y2);
} Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold));
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); //畫圖片的前景噪音點
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()));
} //畫圖片的邊框線
g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1); //將圖片輸出到頁面上
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();
}
}
}
<img id="imgCode" alt="看不清，請點擊我！" src="CheckCode.aspx"
style="cursor: hand; width: 76px; height: 21px" onclick="this.src=this.src+'?'" /> |
