ASP.NET Refresh page on timer; query database in between timer - asp.net

Question

'I have a solution in my head, but am unsure if it is possible in ASP.NET. I don't have a lot of experience with timers. My idea is as follows:
'Code Behind
'At the end of the timer(lets say 1 minute)
Dim qry = "SELECT ISNULL(Value, '') FROM Database.Schema.Table WHERE
Column = #Something"
'set up sql connection and execute query
Using sqlcon as new SQLConnection() 'Don't focus on this part
Using sqlcmd = New SQLCommand(sqlcon,qry) 'Don't focus on this part either syntax is probably incorrect
sqlcmd.Parameters.Add("Something", VarChar)
sqlcmd.Parameters("Something").Value = "Row Found"
'Refresh page; assign label control on .aspx page to value of returned query
'SafeToString() is a function that will safely return a string whether the value is some string, DBNULL, Nothing, or ''
lblString.Text = SafeToString(sqlcmd.ExecuteScalar())
End Using
End Using
I want to be able to do this while maintaining scrolls position as well. So I don't interrupt the work/browsing the user is doing.
Thank you all for your input!

Answer 1

Look up Page Methods. JS can call a code-behind method which can return a value to the js method which can then update the page. The code behind method cannot access the page directly, only return a value to the js method.

Answer 2

I had never used WebForms (which I assume this question is about) but regardless I think you're approaching the problem in a wrong way. A page refresh is destructive and distracting, when a page is refreshed the browser has to fetch the page again (this includes all assets and scripts) and re-render the page.
Client-side implementation
So the solution must be implemented at the client side and not require a full page refresh, this can be achieved using Javascript and ajax(from Wikipedia) requests.
In short ajax is a mechanism for issuing additional requests to a web server while the page is loaded and running. That way you can fetch new data in the background without interrupting the user.
When the page loads set up a timeout or an interval:
let intervalId = setInterval(updateFromServer, 1000);
This interval will call updateFromServer every 1 second (1000ms).
Define the function updateFromServer:
function updateFromServer() {
let newData = fetchData();
updateData(newData);
}
This function is call by the interval we've set up and does 2 things: it fetches new data from the server and pushes it to the DOM using updateData.
You can use ajax (for example with jquery) to fetch the data:
function fetchData() {
return $.ajax({
type: "GET",
url: remote_url,
async: false
}).responseText;
}
This is where ajax comes in, the above lines use jquery ajax api to send a GET request to the server at the url remote_url. The browser issues the request and waits for the server to respond.
And finally update the page (again I'm using jquery):
function updateData(newData) {
$('#data-el').text(newData)
}
Again we are using jquery here (you can use pure javascript though) to find an element with the ID data-el and setting its content to newData.