The function below is found in a class called page.cs

public static List<string> MyFunction()
        {
         var retList = new List<string>();
        
        retList.Add("xzy");
        retList.Add("abc");
        
return retList;
        }

On page load how to call the function and check if the list contains xzy and abc?

 protected void Page_Load(object sender, EventArgs e)
{
    //call MyFunction()
}

CodePudding user response：

You don't really show enough code for us to see your problem. As I read it, you have a class Page in a file named page.cs and it looks like this in part:

public class Page {
    public static List<string> MyFunction()
    {
        var retList = new List<string>
        {
            "xyz",
            "abc",
        };
        return retList;
    }

    protected void Page_Load(object sender, EventArgs e)
    {
        var list = MyFunction();
    }
}

(Note that I've simplified your initialization of the list - my code is equivalent to yours)

The code I show compiles. Assuming that MyFunction and Page_Load are in the same class, then you can directly call MyFunction from Page_Load (static functions can be called from instance function (within the same class)).

If they are not in the same class, let's say that MyFunction was a static function in another class (say OtherClass). Then Page_Load could call it in the way @joelcoehoorn describes:

OtherClass.MyFunction();

The reverse is not true. A static function cannot directly call an instance function (one without the static keyword) in the same class. You'll get an error complaining that you need an instance. For example, if MyFunction wanted to call Page_Load, it would need to do something like this:

var page = new Page();
//possibly do something with page
page.PageLoad(new object(), EventArgs.Empty);
//possibly do more stuff with page

If this doesn't answer your question, you need to add more to your question. In particular:

1. Show the class declarations around your method definitions. It's not clear (but it is important) which class(es) have which methods
2. Show us the code you have and any error messages you get (compile time and runtime)

Also note that I don't believe you should be getting Non-invocable member 'page' cannot be used like a method. if you did what @joelcoehoorn describes.

CodePudding user response：

You have to reference the function using the type name. However, a file named page.cs likely had a class named Page, which will conflict with the base ASP.Net Page class. Therefore you must either fully-qualify the name (MyNamespace.Page.MyFunction()) or change the name of the class.