asp.net扩展login控件时,图片验证码的问题,
对login控件进行扩展,加入图片验证码,第一次运行是正确的,然后进入系统后 点注销,系统返回到login页面,这时图片显示不出来,只显示了alt的文字,各位有没有遇到过这问题,
其中验证码生成文件imageValidate.cs 中主要代码
public partial class imageValidate : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
//生成4位的验证码
/*string tmp = RndNum(4);
HttpCookie cookie = new HttpCookie( "ImageV ", tmp);
//Response.Cookies[ "ImageV "].Value=tmp;
Response.Cookies.Add(cookie);
this.ValidateCode(tmp);*/
CreateCheckCodeImage(GenerateCheckCode());
}
private string GenerateCheckCode()
{
int number;
char code;
string checkCode = String.Empty;
System.Random random = new Random();
for (int i = 0; i < 5; i++)
{
number = random.Next();
if (number % 2 == 0)
code = (char)( '0 ' + (char)(number % 10));
else
code = (char)( 'A ' + (char)(number % 26));
checkCode += code.ToString();
}
Response.Cookies.Add(new HttpCookie( "CheckCode ", checkCode));
return checkCode;
}
private void CreateCheckCodeImage(string checkCode)
{
if (checkCode == null || checkCode.Trim() == String.Empty)
return;