Error: Unable to evaluate expression because the code is optimized . . .

[jagdeep gupta]

The code was executing fine but now an exception is generated: "exc = {Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack.}"

  protected void bsin_Click(object sender, EventArgs e)
    {
        con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
        com = new SqlCommand("Select *From register Where loginname=@loginname And password=@password", con);
        com.Parameters.Add("@loginname", SqlDbType.NVarChar).Value = txtun.Text;
        com.Parameters.Add("@password", SqlDbType.NVarChar).Value = txtpass.Text;
        try
        {
            if (con.State == ConnectionState.Closed)
                con.Open();
           dr = com.ExecuteReader();
            if (dr.Read())
            {
                Session["username"] = txtun.Text;
                Session["password"]=txtpass.Text;
                lplwronguserid.Visible = false;
                Response.Redirect("home.aspx");
 
 
            }
            else
            {
                lplwronguserid.Text = "Wrong Password OR UserID*";
                //Response.Write("Wrong Password OR UserID");
 
 
            }
        }
        catch (Exception exc)
        {
        }
        finally
        {
            con.Close();
        }
 
 
 
 
 
    }
 

[Frinavale]

You have:

 Select *From register Where loginname=@loginname And password=@password

But you need a space in between the * and the From...like this:

Select * From register Where loginname=@loginname And password=@password

-Frinny

[jagdeep gupta]

I have changed that as well but still it is showing the same problem

[ck9663]

This looks like a java/C/C+/C# code. In SQL Server, a "@" sign means it's a variable. In this case those variables are undeclared. That could be the reason for your error. As to some programming languages, it may be unassigned, but it can not be undeclared.

Good Luck!!!

~~ CK

[Frinavale]

It's C#, the variables are declared though...they are being assigned values from TextBoxes on the page here:

  com.Parameters.Add("@loginname", SqlDbType.NVarChar).Value = txtun.Text;
  com.Parameters.Add("@password", SqlDbType.NVarChar).Value = txtpass.Text;

[hype261]

It is often helpful if you tell people which statement is throwing the exception. From looking on google it appears that this isn't a SQL Server problem at all.

I believe the exception is being thrown at Response.Redirect statement at line 17. Here is an MSDN article on the exception and how you can fix it.

http://support.microsoft.com/kb/312629/EN-US/

[Frinavale]

I would never have guessed that it was a Response.Redirect issue (I myself have never experienced this particular error...usually the Response.Redirect("url") method throws "thread abortion error" instead of the error described)

But...change line 17 in the above code from this:

Response.Redirect("home.aspx");

To this:

Response.Redirect("home.aspx",true);

Providing "true" as the second parameter to the Response.Redirect() method will prevent the rest of the page from being executed. This will avoid "thread abortion" errors.


Be Sure to Close your connection Before you Response.Redirect away from the page!

It might be best to use a boolean to flag whether or not to Response.Redirect the user...like this:

protected void bsin_Click(object sender, EventArgs e)
{   boolean redirectUser = false;
        con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
        com = new SqlCommand("Select *From register Where loginname=@loginname And password=@password", con);
        com.Parameters.Add("@loginname", SqlDbType.NVarChar).Value = txtun.Text;
        com.Parameters.Add("@password", SqlDbType.NVarChar).Value = txtpass.Text;
        try
        {
            if (con.State == ConnectionState.Closed)
                con.Open();
            dr = com.ExecuteReader();
            if (dr.Read())
            {
                Session["username"] = txtun.Text;
                Session["password"] = txtpass.Text;
                lplwronguserid.Visible = false;
                redirectUser = true;
            }
            else
            {
                lplwronguserid.Text = "Wrong Password OR UserID*";
 
            }
        }
        catch (Exception exc)
        {
        }
        finally
        {
            con.Close();
        }
        if(redirectUser)
        {
           Response.Redirect("home.aspx",true);
        }
}

-Frinny

[jagdeep gupta]

thanks frinny ,
Now it is redirecting but exception is still there

[hype261]

Jagdeep,

What line of code is the exception being thrown at?

[Frinavale]

Where is it being thrown?

You have a Try-Catch block that catches all Exceptions and does nothing with them....

-Frinny

[jagdeep gupta]

line no 34
n thanks for considering my request

[ZiadElmalki]

Is this a ThreadAbortException? How are you seeing the exception?


ASP.NET will abort threads to handle control flow. If you do a Response.Redirect it calls Response.End which does the Thread.Abort(). This should not be an issue.

[jagdeep gupta]

no sir the exception is same as written above by me

[ZiadElmalki]

exc = {Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack.}"


That is not an exception. Thats an error message from the debugger.

The issue is due to the thread being aborted. Here are some posts fro people with the same issue.

http://www.west-wind.com/Weblog/posts/6931.aspx

http://bytes.com/topic/asp-net/answe...ate-expression

http://geekswithblogs.net/vadivelkum.../25/70703.aspx


Here is a KB article describing the issue.
http://support.microsoft.com/kb/312629/EN-US/

Good Luck

[Frinavale]

jagdeep gupta,

Could you please post your updated code so that we can see what is going on?

-Frinny

[jagdeep gupta]

 
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.Data.SqlClient;
 
public partial class loginpage : System.Web.UI.Page
{
    SqlConnection con;
    SqlCommand com;
    SqlDataReader dr;
    protected void Page_Load(object sender, EventArgs e)
    {
     //Response.Write("Welcome" + " " + Session["username"]+ " " + Session["lastname"]);
 
    }
 
    protected void lbnew_Click(object sender, EventArgs e)
    {
        Response.Redirect("registration.aspx");
 
    }
    protected void bsin_Click(object sender, EventArgs e)
    {
        con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
        com = new SqlCommand("Select * From register Where loginname=@loginname And password=@password", con);
        com.Parameters.Add("@loginname", SqlDbType.NVarChar).Value = txtun.Text;
        com.Parameters.Add("@password", SqlDbType.NVarChar).Value = txtpass.Text;
        try
        {
            if (con.State == ConnectionState.Closed)
                con.Open();
           dr = com.ExecuteReader();
            if (dr.Read())
            {
                Session["username"] = txtun.Text;
                Session["password"]=txtpass.Text;
                lplwronguserid.Visible = false;
                con.Close();
                Response.Redirect("home.aspx",true);
 
 
            }
            else
            {
                lplwronguserid.Text = "Wrong Password OR UserID*";
                //Response.Write("Wrong Password OR UserID");
 
 
            }
        }
        catch (Exception exc)
        {
        }
        finally
        {
            con.Close();
        }
 
 
 
}
 

[Frinavale]

Jagdeep Gupta,

I mentioned before that you should do your redirect after you close your connection.

I also mentioned that you should use Response.Redirect("url", true) to redirect the user so that you avoid problems with Thread Abortion exceptions.

Like This:

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.Data.SqlClient;
 
public partial class loginpage : System.Web.UI.Page
{
    SqlConnection con;
    SqlCommand com;
    SqlDataReader dr;
    protected void Page_Load(object sender, EventArgs e)
    {   }
 
    protected void lbnew_Click(object sender, EventArgs e)
    {
        Response.Redirect("registration.aspx", true);
    }
    protected void bsin_Click(object sender, EventArgs e)
    {
        con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
        com = new SqlCommand("Select * From register Where loginname=@loginname And password=@password", con);
        com.Parameters.Add("@loginname", SqlDbType.NVarChar).Value = txtun.Text;
        com.Parameters.Add("@password", SqlDbType.NVarChar).Value = txtpass.Text;
        try
        {
            if (con.State == ConnectionState.Closed)
                con.Open();
           dr = com.ExecuteReader();
            if (dr.Read())
            {
                Session["username"] = txtun.Text;
                Session["password"]=txtpass.Text;
                lplwronguserid.Visible = false;
                con.Close();
//I removed the redirect from here
            }
            else
            {
                lplwronguserid.Text = "Wrong Password OR UserID*";
            }
        }
        catch (Exception exc)
        {
        }
        finally
        {
            con.Close();
        }
 
//I put it HERE...after closing the connection
        if( Session["username"] != null)
        {
          Response.Redirect("home.aspx",true);
        }
  }
}

-Frinny