复制代码 代码如下:

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;

using System.Drawing.Drawing2D;

public partial class _Default : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

Bitmap bmp = new Bitmap(50, 25);

Graphics g = Graphics.FromImage(bmp);

SolidBrush sb = new SolidBrush(getColor());

g.DrawString(CheckNumber(), new Font("宋体", 16), sb, 0, 0);

bmp.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Gif);

}

public static string CheckNumber()

{

string checkcode = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

int len = 4;

string tmpstr = "";

int iRandNum;

Random rnd = new Random();

for (int i = 0; i < len; i++)

{

iRandNum = rnd.Next(checkcode.Length);

tmpstr += checkcode[iRandNum];

}

return tmpstr;

}

private Color getColor()

{

Random r = new Random();

return Color.FromArgb(r.Next(256), r.Next(256), r.Next(256));

}

}