Question

I am working on an ASP .net project. I am trying to load a user control in a Control object with the following code and i am trying to pass a parameter to that control. On the debugging mode I get an error on that line saying that The file '/mainScreen.ascx?matchID=2' does not exist.. If I remove the parameters then it works ok. Can anyone help me to pass those parameters? Any suggestions?

    Control CurrentControl = Page.LoadControl("mainScreen.ascx?matchID=2");

Answer 1

You cannot pass the parameter via query-string notation because user controls are simply “a building blocks” referenced by virtual path.

What you can do instead is to make a public property and assign the value to it once the control is loaded:

public class mainScreen: UserControl
{
    public int matchID { get; set; }
}

// ...

mainScreen CurrentControl = (mainScreen)Page.LoadControl("mainScreen.ascx");
CurrentControl.matchID = 2;

You can now use the matchID inside your user control like the following:

private void Page_Load(object sender, EventArgs e)
{
    int id = this.matchID;

    // Load control data
}

Note that the the control is participating in the page life cycle only if it’s added into the page tree:

Page.Controls.Add(CurrentControl); // Now the "Page_Load" method will be called

Hope this helps.