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;
using System.IO;
/// <summary>
/// 生成随机验证码
/// </summary>
public partial class ProductInfo_Login_Range : System.Web.UI.Page
{
Random random = new Random();
protected void Page_Load(object sender, EventArgs e)
{
string str = getRandomValidate(4);
Session.Add("RangeCode",str); //这一步是为了将验证码写入Session,进行验证,不能缺省,也可一使用cookie
//HttpCookie cook = new HttpCookie("code");
//cook.Value = str;
getImageValidate(str);
}
//得到随机字符串,长度自己定义
private string getRandomValidate(int len)
{
int num;
int tem;
string rtuStr = "";
for (int i = 0; i < len; i++)
{
num = random.Next();
if (num % 2 == 0)
tem = num % 10 + '0';//生成数字
else
tem = num % 26 + 'A';//生成字符
rtuStr += Convert.ToChar(tem).ToString();
}
return rtuStr;
}
//生成图像
private void getImageValidate(string strValue)
{
//string str = "OO00"; //前两个为字母O,后两个为数字0
int width = Convert.ToInt32(strValue.Length * 12); //计算图像宽度
Bitmap img = new Bitmap(width, 23);
Graphics gfc = Graphics.FromImage(img); //产生Graphics对象,进行画图
gfc.Clear(Color.White);