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 CnCode : 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 = 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[])));
//输出的控制台
CreateImage(str1 + str2 + str3 + str4);
}
/*
此函数在汉字编码范围内随机创建含两个元素的十六进制字节数组,每个字节数组代表一个汉字,并将
四个字节数组存储在object数组中。
参数:strlength,代表需要产生的汉字个数
*/
public static object[] CreateRegionCode(int strlength)
{
//定义一个字符串数组储存汉字编码的组成元素
string[] rBase=new String [16]{"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};
Random rnd=new Random();
//定义一个object数组用来
object[] bytes=new object[strlength];
/**//*每循环一次产生一个含两个元素的十六进制字节数组,并将其放入bject数组中
每个汉字有四个区位码组成
区位码第1位和区位码第2位作为字节数组第一个元素
区位码第3位和区位码第4位作为字节数组第二个元素
*/
for(int i=0;i<strlength;i++)
{
//区位码第1位
int r1=rnd.Next(11,14);
string str_r1=rBase[r1].Trim();
//区位码第2位
rnd=new Random(r1*unchecked((int)DateTime.Now.Ticks)+i);//更换随机数发生器的种子避免产生重复值
int r2;
if (r1==13)
{
r2=rnd.Next(0,7);
}
else
{
r2=rnd.Next(0,16);
}
string str_r2=rBase[r2].Trim();
//区位码第3位
rnd=new Random(r2*unchecked((int)DateTime.Now.Ticks)+i);
int r3=rnd.Next(10,16);
string str_r3=rBase[r3].Trim();
//区位码第4位
rnd=new Random(r3*unchecked((int)DateTime.Now.Ticks)+i);
int r4;
if (r3==10)
{
r4=rnd.Next(1,16);
}
else if (r3==15)
{
r4=rnd.Next(0,15);
}
else
{
r4=rnd.Next(0,16);
}
string str_r4=rBase[r4].Trim();
//定义两个字节变量存储产生的随机汉字区位码
byte byte1=Convert.ToByte(str_r1 + str_r2,16);
byte byte2=Convert.ToByte(str_r3 + str_r4,16);
//将两个字节变量存储在字节数组中
byte[] str_r=new byte[]{byte1,byte2};
//将产生的一个汉字的字节数组放入object数组中
bytes.SetValue(str_r,i);
}
return bytes;
}
private void CreateImage(string checkCode)
{
int iwidth = (int)(checkCode.Length * 25);
System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 20);
Graphics g = Graphics.FromImage(image);
Font f = new System.Drawing.Font("Arial", 12, System.Drawing.FontStyle.Bold);
Brush b = new System.Drawing.SolidBrush(Color.White);
//g.FillRectangle(new System.Drawing.SolidBrush(Color.Blue),0,0,image.Width, image.Height);
g.Clear(Color.Blue);
g.DrawString(checkCode, f, b, 3, 3);
Pen blackPen = new Pen(Color.Black, 0);
Random rand = new Random();
for (int i = 0; i < 4; i++)
{
int y = rand.Next(image.Height);
g.DrawLine(blackPen, 0, y, image.Width, y);
}
System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
Response.ClearContent();
Response.ContentType = "image/png";
Response.BinaryWrite(ms.ToArray());
g.Dispose();
image.Dispose();
}
}
该文章转载自'大智の博客':?id=1274
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