字符串未被識別為有效的DateTime

Question

我的代碼是.......

  string PName = Request.QueryString["ProductName"] as string;
  string myDate = Request.QueryString["period"];

 string sql = "select FileName from tblProduct Where ProductName=" + PName;



    DateTime dt1 = Convert.ToDateTime(myDate);
    DateTime dt2 = DateTime.Now;
    TimeSpan variable = dt2 - dt1;
    if (variable.TotalMinutes > 5)
    {
        //Response.Write("Download time is expired now");
        lblmsg.Visible = true;
        lblmsg.Text = "Download time is expired now";
    }
    else
    {
        //string url1 = " http://www.shreehans.co.in/files/" + PName +"";
        //Response .Redirect ()
        lblmsg.Visible = true;
        lblmsg.Text = "U can Still Download";
    }

而且我的URl帶有querystring參數...

mail.Body + = string.Format（“ http://www.abc.co.in/Download.aspx?period=” + DateTime.Now +“＆ProductName =” + productName +“ \\”>演示下載“）;

Answer 1

如果在url（查詢字符串）中包含日期，則應將其編碼為Server.UrlEncode(DateTime.Now) 。

Answer 2

此外：

1. 構造URI時，您缺少\\" 。
2. 您的SQL代碼容易受到SQL注入攻擊。

Answer 3

這樣可以解決您的問題

mail.Body += 
   string.Format("http://www.abc.co.in/Download.aspx?period=" + 
   DateTime.Now.ToString("dd-MMM-yyyy") + 
   "&ProductName=" + productName + "\">Demo Download");