aps.net的验证码
IRequiresSessionState加这一个解析不然显示不出来针对session
using (System.Drawing.Bitmap bitmp = new System.Drawing.Bitmap(150, 80))
{
using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmp))
{
Random rand = new Random();
int code = rand.Next(1000,9999);
string strcode = code.ToString();
HttpContext.Current.Session["Code"] = strcode;
g.DrawString(strcode, new System.Drawing.Font("宋体", 18), System.Drawing.Brushes.Green, new System.Drawing.PointF(0, 0));
bitmp.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
}
}
鼠标点击能够随机读取每一张不同的数字
<img src="yzm.ashx" onclick="this.src='yzm.ashx?a='+new Date()"/>加一个时间