png.aspx.cs

学习积累的代码段

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.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Drawing.Text;
using System.Drawing;
using System.Text; 

public partial class png : System.Web.UI.Page
{
    private readonly string ImagePath = "Validator.jpg";
    private static string gif = "";

    protected void Page_Load(object sender, EventArgs e)
    {

        switch (Request.QueryString["aa"])
        {
            case "1":
                gif = stxt();
                Session["gif"]= stxt();
                break;
            case "2":
                gif = GetRandomint();
                 Session["gif"]= GetRandomint();
                break;
            case "3":
                gif = RndNum(3);
                 Session["gif"]= RndNum(3);
                break;
            default:
                gif = RndNum(3);
                 Session["gif"]= GetRandomint();
                break;
        }
        
        ///创建Bmp位图
        Bitmap bitMapImage = new System.Drawing.Bitmap(Server.MapPath(ImagePath));
        Graphics graphicImage = Graphics.FromImage(bitMapImage);

        ///设置画笔的输出模式
        graphicImage.SmoothingMode = SmoothingMode.HighSpeed;
        ///添加文本字符串
        graphicImage.DrawString(gif, new Font("Arial", 20, FontStyle.Bold), SystemBrushes.WindowText, new Point(0, 0));

        ///设置图像输出的格式
        Response.ContentType = "image/jpeg";

        ///保存数据流
        bitMapImage.Save(Response.OutputStream, ImageFormat.Jpeg);

        ///释放占用的资源
        graphicImage.Dispose();
        bitMapImage.Dispose();
    }
    private String GetRandomint()
    {
        Random random = new Random();
        return (random.Next(100000, 999999).ToString());
    }
            /**//* 
        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 string stxt()
    {
        Encoding gb = Encoding.GetEncoding("gb2312");

        //调用函数产生4个随机中文汉字编码 
        object[] bytes = CreateRegionCode(3);

        //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 txt = str1 + str2 + str3;
        return txt;
    }
    /// <summary>
    /// 这个是使用文字,字母,数字混合
    /// </summary>
    /// <param name="VcodeNum"></param>
    /// <returns></returns>
    public String RndNum(int VcodeNum)
    {
        String Vchar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z,呵,哈,弹,簧,秤,嬉,戏";
        String[] VcArray = Vchar.Split(',');
        String VNum = "";
        Random random = new Random();
        for (int i = 1; i <= VcodeNum; i++)
        {
            int iNum = 0;
            while ((iNum = Convert.ToInt32(VcArray.Length * random.NextDouble())) == VcArray.Length)
            {
                iNum = Convert.ToInt32(VcArray.Length * random.NextDouble());
            }
                 VNum += VcArray[iNum];
            }
        return VNum;
    } 
}