生成中文验证码

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)
{
//获取GB2312编码页（表）
Encoding gb = Encoding.GetEncoding("gb2312");

//调用函数产生4个随机中文汉字编码
object[] bytes = ChineseCode.CreateRegionCode(4);

//根据汉字编码的字节数组解码出中文汉字
string str1 = gb.GetString((byte[])Convert.ChangeType(bytes[0], typeof(byte[])));
string str2 = gb.GetString((byte[])Convert.ChangeType(bytes[1], typeof(byte[])));
string str3 = gb.GetString((byte[])Convert.ChangeType(bytes[2], typeof(byte[])));
string str4 = gb.GetString((byte[])Convert.ChangeType(bytes[3], typeof(byte[])));
string[] str = new string[] { str1, str2, str3, str4 };

CreateCheckCodeImage(str);

PublicCla.HZ = str1 + str2 + str3 + str4;         ///（PublicCla.HZ）这个是保存的四个文字信息
}

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)), 70);
System.Drawing.Graphics g = Graphics.FromImage(image);

try
{
//生成随机生成器
Random random = new Random();

//清空图片背景色
g.Clear(Color.White);

//画图片的背景噪音线
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);
}

//定义颜色
Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };
//定义字体
string[] f = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" };

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);
}

//画图片的前景噪音点
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()));
}

//画图片的边框线
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();
}
}
}