图形验证码的c# 实现

GraphicValidate.ascx   客服端刷新文件代码


   
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GraphicValidate.aspx.cs  图形文件代码

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.IO;
using System.Drawing.Imaging;
using System.Drawing;

public partial class UserControl_GraphicValidate : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
      
        string tmp = RndNum(4);
        Session["v"] = tmp;
        this.ValidateCode(tmp);
       
    }

 

 

    private void ValidateCode(string VNum)
    {
        System.Drawing.Bitmap Img = null;
        System.Drawing.Graphics g = null;
        MemoryStream ms = null;

        int gheight = VNum.Length * 12;
        Img = new Bitmap(gheight, 25);
        g = Graphics.FromImage(Img);
        //背景颜色
        g.Clear(Color.White);
        //文字字体
        Font f = new Font("Arial Black", 10);
        //文字颜色
        SolidBrush s = new SolidBrush(Color.Black);
        g.DrawString(VNum, f, s, 3, 3);
        ms = new MemoryStream();
        Img.Save(ms, ImageFormat.Jpeg);
        Response.ClearContent();
        Response.ContentType = "image/Jpeg";
        Response.BinaryWrite(ms.ToArray());

        g.Dispose();
        Img.Dispose();
      
       Response.End();
       
    }

    private 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,v,w,x,y,z";
        string[] VcArray = Vchar.Split(new Char[] { ',' });
        string VNum = "";
        int temp = -1;

        Random rand = new Random();

        for (int i = 1; i < VcodeNum + 1; i++)
        {
            if (temp != -1)
            {
                rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks));
            }

            int t = rand.Next(35);
            if (temp != -1 && temp == t)
            {
                return RndNum(VcodeNum);
            }
            temp = t;
            VNum += VcArray[t];
        }
        return VNum;
    }

}

转载于:https://www.cnblogs.com/koolay/articles/922857.html

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