Catch error in GridView automatic databinding

Question

I have a gridview with a DataSourceID set, so the databinding happens automatically. The problem is that sometimes, the procedure defined in the SqlDataSource takes a very long time to finish, so the binding comes with a timeout expired error.

How can I catch this error without manually databinding the gridview and surrounding it with try/catch statements?

Answer 1

Why not fix the problem with the query timing out instead? Either optimise the DB (preferred) or set the connection/command timeout to be higher than the current value.

You can adjust the timeout as follows by hooking into the SqlDataSource Selecting event:

protected void ds_Selecting(object sender, SqlDataSourceSelectingEventArgs e)
    {
        e.Command.CommandTimeout = 5000;
    }

If you are using SQL Server you might want to look at tools like the index tuning wizard/tuning advisor, show query execution plan or SQL Server Profiler.

Answer 2

how about binding asynchronously? once completed, the callback function can call databind if no errors were returned.

EDIT: I guess that's manual...not what you wanted.

Answer 3

The only think you can do is handling the Page_Error Event

http://msdn.microsoft.com/en-us/library/ed577840.aspx

Answer 4

If an exception occurs when the SqlDataSource is executing, it fires its appropriate post-action event - Selected, in this case. You can optionally create an event handler for this event and in the event handler say that you've handled the exception.

This diagram shows how this interaction works with the ObjectDataSource (the concept is the same with the SqlDataSource control). When examining the diagram below, replace the words "ObjectDataSource" with "SqlDataSource" and "Underlying Object" with "Database" to have it be pertinent for the SqlDataSource.

As you can see, the Selecting event is raised before the data is sent off to the database and the Selected event is raised after the data comes back (or if there's an exception).

You can create a Selected event handler in your page and check to see if an exception occurred and decide whether you want to handle it yourself. Fredrik Normen has a good blog entry on this: Handle the data-source control exception by your own.

Additional reading material: Accessing and Updating Data in ASP.NET: Examining the Data Source Control's Events.

Happy Programming!