FindPwd/RandonNum.aspx.cs

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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;

public partial class RandonNum : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string str = Getrandom();
        //存储验证码
        Session["code"] = str;
        //图(取绝对路径)
        System.Drawing.Image img = System.Drawing.Image.FromFile(Server.MapPath("Image/1.jpg"));
        //绘图对象(指向图)
        Graphics g = Graphics.FromImage(img);
        //在图上写字
        //g.DrawString(str, new Font("Airal", 1, FontStyle.Bold), Brushes.Red, new Point(0, 0));
        //Font font = new System.Drawing.Font("Arial", 25, FontStyle.Bold);
        Font font = new System.Drawing.Font("", 25, FontStyle.Bold);

        //渐变色彩
        System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, img.Width, img.Height), Color.Tomato, Color.Red, 1.8f, true);
        //g.DrawString(str,font, brush, 2, 2);
        g.DrawString(str, font, brush, 8, -1);

        //画图片的边框线
        g.DrawRectangle(new Pen(Color.Silver), 0, 0, img.Width - 1, img.Height - 1);
        // 下载于www.51aspx.com
        //保存图片
        img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
    }

    private string Getrandom()
    {
        //获取随机数
        Random rand = new Random();
        //获取四位的随机数
        int i = rand.Next(1000, 10000);
        //获取由数字和字母组成的随机数
        string[] str = new string[] { "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 code = string.Empty; //只读
        for (int j = 0; j < 4; j++)
        {
            i = rand.Next(0, 36);
            code += str[i];
        }
        return code;
    }
}