using System;
using System.Data;
using System.Configuration;
using System.Collections;
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.Text;
using System.Drawing;
public partial class Img : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string[] str = new string[4];
string serverCode=;
//生成隨機(jī)生成器
Random random = new Random();
for (int i = 0; i < 4; i++)
{
str[i] = random.Next(10).ToString().Substring(0,1);
}
CreateCheckCodeImage(str);
foreach(string s in str)
{
serverCode += s;
}
Session[serverCode] = serverCode;
}
private void CreateCheckCodeImage(string[] checkCode)
{
if (checkCode == null || checkCode.Length <= 0)
return;
System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 32.5)), 30);
System.Drawing.Graphics g = Graphics.FromImage(image);
try
{
Random random = new Random();
//清空?qǐng)D片背景色
g.Clear(Color.White);
//畫(huà)圖片的背景噪音線
for (int i = 0; i < 20; 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.Silver), x1, y1, x2, y2);
}
//定義顏色
Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };
//定義字體
string[] f = { Verdana, Microsoft Sans Serif, Comic Sans MS, Arial, 宋體 };
for (int k = 0; k <= checkCode.Length - 1; k++)
{
int cindex = random.Next(7);
int findex = random.Next(5);
Font drawFont = new Font(f[findex], 16, (System.Drawing.FontStyle.Bold));
SolidBrush drawBrush = new SolidBrush(c[cindex]);
float x = 5.0F;
float y = 0.0F;
float width = 20.0F;
float height = 25.0F;
int sjx = random.Next(10);
int sjy = random.Next(image.Height - (int)height);
RectangleF drawRect = new RectangleF(x + sjx + (k * 25), y + sjy, width, height);
StringFormat drawFormat = new StringFormat();
drawFormat.Alignment = StringAlignment.Center;
g.DrawString(checkCode[k], drawFont, drawBrush, drawRect, drawFormat);
}
//畫(huà)圖片的前景噪音點(diǎn)
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(huà)圖片的邊框線
g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
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();
}
}
}
