Nested try-catch with Reponse.Redirect in ASP.NET

Question

I have nested try catch blocks

try
{
    // statements
    try
    {
        // statements
    }
    catch(SqlException sqlex)
    {
        Response.Redirect(@"~/Error.aspx?err=" + Server.UrlEncode(sqlex.Message)
                              + "&src=" + Server.UrlEncode(sqlex.ToString()));
    }
    catch (Exception ex)
    {
        Response.Redirect(@"~/Error.aspx?err=" + Server.UrlEncode(ex.Message)
                              + "&src=" + Server.UrlEncode(ex.ToString()));
    }
    finally
    {
        conn.Close();
    }
}
catch (Exception ex)
{
    Response.Redirect(@"~/Error.aspx?err=" + Server.UrlEncode(ex.Message)
                          + "&src=" + Server.UrlEncode(ex.StackTrace)); 
}
finally
{
    conn.Close();
}

If a SqlExeception is caught at inner first catch block, then also because try...catch surrounds Response.Redirect, the ThreadAbortException generated by the transfer is caught by the outer catch block.

How can I solve this problem? Thanks!

Answer 1

Read this article

What you can do most simply is not redirect inside your try/catch harnesses:

string url ;
try 
     { 
            // statements 
            try 
            { 
            } 
            catch(SqlException sqlex) 
            { 
               url = @"~/Error.aspx?err=" + Server.UrlEncode(sqlex.Message) + "&src=" + Server.UrlEncode(sqlex.ToString()); 
            } 
            catch (Exception ex) 
            { 
                url = @"~/Error.aspx?err=" + Server.UrlEncode(ex.Message) + "&src=" + Server.UrlEncode(ex.ToString()); 
            } 
            finally 
            { 
                conn.Close(); 
            } 
    } 
    catch (Exception ex) 
        { 
            url = @"~/Error.aspx?err=" + Server.UrlEncode(ex.Message) + "&src=" + Server.UrlEncode(ex.StackTrace);  
        } 
        finally 
        { 
            conn.Close(); 
        } 
} 

if ( url != "" ) {
    Response.Redirect(url);
}
else {
    // Page logic can continue
}

Answer 2

Consider changing the code in the first response

if ( url != "" ) { Response.Redirect(url);}

to

if (!string.IsNullOrEmpty(url)) { Response.Redirect(url);}

Answer 3

Use a variable to track when an error has been thrown in the inner try...catch and then check it in the second by surrounding the Response.Redirect with an if statement.

Answer 4

Whenever you use Response.Redirect inside a try-catch block, you should add the second parameter.

Instead of this:

Response.Redirect("somepage.aspx");

Do this:

Response.Redirect("somepage.aspx", false);

When that boolean is true, the page contents are sent to the new page (so you can use the form values). When that boolean is false, the page contents are not sent. This is probably what you want. You would know if you needed true.

Another approach to this is to catch the ThreadAbortException in an empty Catch block.