我已经在 asp.net 中实现了 CAPTCHA,它在验证之前运行良好,但是当我要验证它时,程序会忽略任何输入文本并表现为“不正确”,你能告诉我它有什么问题吗?请问我可以吗?这是代码:
public partial class WebForm1 : System.Web.UI.Page
{
//string strResult;
protected string Captcha()
{
string alphabt = "QWERTYUIOPASDFGHJKLZXCVBNM0123456789";
Random rand = new Random();
int num1 = rand.Next(1, 36);
int num2 = rand.Next(1, 36);
int num3 = rand.Next(1, 36);
int num4 = rand.Next(1, 36);
int num5 = rand.Next(1, 36);
int num6 = rand.Next(1, 36);
string subStr1 = alphabt.Substring(num1, 1);
string subStr2 = alphabt.Substring(num2, 1);
string subStr3 = alphabt.Substring(num3, 1);
string subStr4 = alphabt.Substring(num4, 1);
string subStr5 = alphabt.Substring(num5, 1);
string subStr6 = alphabt.Substring(num6, 1);
string result = subStr1 + subStr2 + subStr3 + subStr4 + subStr5 + subStr6;
Session["res"] = result;
Bitmap bmpImage = new Bitmap(Server.MapPath("~/Image/bg1.jpg"));
Graphics objGraphic = Graphics.FromImage(bmpImage);
objGraphic.DrawString(result, new Font("arial", 12, FontStyle.Strikeout), SystemBrushes.WindowText, new PointF());
string time = DateTime.Now.Ticks.ToString();//due to browser image cashing
//bmpImage.Save(Server.MapPath("~/Image/securityImage.jpg"));
//return "~/Image/securityImage.jpg";
bmpImage.Save(Server.MapPath("~/Image/securityImage" + time + ".jpg"));
return "~/Image/securityImage" + time + ".jpg";
}
protected bool CaptchaValidate()
{
if (Session["res"].ToString() == TextBox1.Text)
return true;
return false;
}
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
Image1.ImageUrl = Captcha();
}
protected void btn1_Click(object sender, EventArgs e) //using ajax to refresh the picture
{
Image1.ImageUrl = Captcha();
}
protected void Button2_Click(object sender, EventArgs e)
{
if (CaptchaValidate() == false)
Label1.Text = "Incorrect ";
else
Label1.Text = "correct";
}
}
提前致谢...