Error Handling in Web Form - asp.net

Question

I'm trying to cater for an error in my data access layer, which would return an int of value -1. See below:
protected void FolderBtn_Click(object sender, EventArgs e)
{
if (Page.IsValid)
{
try
{
DocsDALC dalc = new DocsDALC();
// Updating two tables here - Folders and FolderAccess tables
// - as an ADO.NET transaction
int folderID = dalc.CreateFolder(...);
if (folderID > 0)
{
Response.Redirect(Request.Url.ToString(), false);
// Re-construct this to include newly-created folderID
}
else
{
// How do I throw error from here?
}
}
catch (Exception ex)
{
HandleErrors(ex);
}
}
}
If data layer returns -1, how can I throw an error from within the try block?

Answer 1

As simply as the following - however, since you are catching errors, if you know it's a problem, it would be better to call an overload of HandleErrors method that you could pass in a string defining the problem, rather than throw the exception (which is costly for what this will do).
If you still want to throw the exception:
if (folderID > 0)
{
Response.Redirect(Request.Url.ToString(), false);
// Re-construct this to include newly-created folderID
}
else
{
throw new Exception("Database returned -1 from CreateFolder method");
}
A possible alternative:
if (folderID > 0)
{
Response.Redirect(Request.Url.ToString(), false);
// Re-construct this to include newly-created folderID
}
else
{
HandleErrors("Database returned -1 from CreateFolder method");
}
With of course an overloaded HandleErrors method.