How can I pass EventHandler as a method parameter

Question

I am trying to write a generic method that will also handle a click event, and I want to allow the user to pass his own method as the click event. Something like this:

public static void BuildPaging(
    Control pagingControl, short currentPage, short totalPages,  ???)
{
    for (int i = 0; i < totalPages; i++)
    {
        LinkButton pageLink = new LinkButton();
        ...
        pageLink.Click += ???;
        pagingControl.Controls.Add(paheLink);
    }
}

I know it is possible but I don't remember how to do it...

possible duplicate of [How to pass an event to a method?](http://stackoverflow.com/questions/2560258/how-to-pass-an-event-to-a-method) — pritaeas, Jan 12 '15 at 10:52

score 27 · Accepted Answer · answered Jan 12 '15 at 10:52

Just use the type of the event handler as argument type:

public static void BuildPaging(Control pagingControl
                              , short currentPage
                              , short totalPages
                              , EventHandler eh // <- this one
                              )
{
    for (int i = 0; i < totalPages; i++)
    {
        LinkButton pageLink = new LinkButton();
        ...
        pageLink.Click += eh;
        pagingControl.Controls.Add(paheLink);
    }
}

Note: Don't forget to remove the event handler when done or you might leak memory!

@LiranFriedman: No need to. [`EventHandler`](http://msdn.microsoft.com/en-us/library/system.eventhandler%28v=vs.110%29.aspx) is a delegate already. See its signature. — Patrick Hofman, Jan 12 '15 at 11:03

score 1 · Answer 2 · answered Jan 12 '15 at 10:53

you can pass action delegate to function

public static void BuildPaging(Control pagingControl, 
            short currentPage, short totalPages,  Action<type> action)

  for (int i = 0; i < totalPages; i++)
{
    LinkButton pageLink = new LinkButton();
    ...
    pageLink.Click += action;
    pagingControl.Controls.Add(paheLink);
}

score 0 · Answer 3 · answered Jan 12 '15 at 10:52

0

Something like this?

void DoWork(Action<object, EventArgs> handler)
{
    if (condition)
    {
        OnSomeEvent(this, EventArgs.Empty);
    }
}

void OnSomeEvent(object sender, EventArgs e)
{

}

Passing it as an argument:

DoWork(OnSomeEvent);

answered Jan 12 '15 at 10:52

Emile Pels

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But the click event does not accept "handler" as a valid value – Liran Friedman Jan 12 '15 at 11:05

How can I pass EventHandler as a method parameter

3 Answers3