Aspx and Ascx lifecycles : avoid multiple select on database

Question

I use an ascx user control for manage CRUD o database entity. I reuse this userc control in my aspx page for show in readonly mode the database data of a record on database. The user control have inside a simple FormView and an objectdatasource.

Now, in a aspx page that contains that ascx i have to know, in DATABIND time of the aspx some data of the record of the database that is considerate by the user control. User control are databind after the aspx page, and for this reason i don't have the data. I have to do a select in aspx page on database and after the user control do the same select.

How can i do for optimize this process?

Answer 1

ASCX base events may be fired after your ASPX's base events, but in the whole lifecycle, you can fire your own events.

You could define an Event on your ASCX, make your page register to this event, and then propagate your custom event from your ASCX to your ASPX, with whatever data you need in the arguments

rough example (may not compile) : in the ASCX

public partial YourControl : System.Web.UI.UserControl {
    public event EventHandler MyControlDataBound;
    public void FireMyControlDataBound()
    {
        if (MyControlDataBound!= null)
        {
            MyControlDataBound(this, new EventArgs());
        }
    }

    protected void MyDataBound(object sender, EventArgs e) {
        // ......
        FireMyControlDataBound();
    }
}

and in the ASPX

public partial class MyPage: Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        yourUserControlInstance.MyControlDataBound += HandleYourDataInYourPage;
    }

    protected void HandleYourDataInYourPage(object sender, EventArgs e) {
        // .. do whatever needed in your page, with your data
        // if you have defined a custom Args class that inherits EventArgs, your could collect data here...
    }
}

Feel free to create a class that inherits EventArgs to pass data with your event if you need this