Adding a click event to a dynamically generated button in C#

Question

So i'm currently trying to get a simply cart working in a website. Basically, as the items are displayed from your cart on the cart page, a panel is populated with images, labels and buttons relating to each one.

What I want to do is assign a click event to every button created that calls a generic method to remove that item from the list. Here's the code for removing the item from the arraylist of items:

public void Remove(CartItem item)
{ 
    ArrayList remove = (ArrayList)Session["ShoppingBasket"];
    remove.Remove(item);
}

This is the event handler I'm trying to code for every button that's generated:

btnRemove.Click += new EventHandler(Remove(item));

For some reason, an error message is coming up saying that a method name is expected in the above line of code and I can't see where I'm going wrong. I'm not too familiar with using the EventHandler object so any guidance there would be greatly appreciated.

Fᴀʀʜᴀɴ Aɴᴀᴍ · Accepted Answer · 2015-12-23 16:27:36Z

3

The EventHandler should match the signature of the Event. You can't just pass any method as an EventHandler. You need a proper void matching the signature of the event.

You can instead try a lambda expression:

btnRemove.Click += (_sender, _args) => Remove(item);

You could have used a separate method but since you need to pass the item to the function Remove, you need to use to use a lambda expression to be able to access item in the context.

edited Dec 23, 2015 at 16:27

answered Dec 23, 2015 at 16:16

Fᴀʀʜᴀɴ Aɴᴀᴍ

6,2815 gold badges33 silver badges53 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Salah Akbari Over a year ago

new EventHandler is redundant. Simplify it like this: btnRemove.Click += (s, e) => Remove(item);

Fᴀʀʜᴀɴ Aɴᴀᴍ Over a year ago

@user2946329 Yes. I just copied it from the Original Post.

Mark O'Hare Over a year ago

I've tried this method but now its having a problem with the EventArgs parameter. it says: "e cannot be declared in this scope because that name is used in an enclosing local scope to define a local or parameter". Should I just use a different name for 'e'?

Fᴀʀʜᴀɴ Aɴᴀᴍ Over a year ago

Oh, yes if you use this in another handler then you can just use a different name, it will work fine.

Fᴀʀʜᴀɴ Aɴᴀᴍ Over a year ago

@Mark Consider accepting this answer so that future readers can find it useful too :)

tchelidze · Accepted Answer · 2015-12-23 16:23:36Z

0

Try this .

btnRemove.Click += (e,s)=> remove(item)

answered Dec 23, 2015 at 16:23

tchelidze

8,3781 gold badge33 silver badges51 bronze badges

1 Comment

tchelidze Over a year ago

o yes, i just run IDE to check it syntactically while other posted answer.

Collectives™ on Stack Overflow

Adding a click event to a dynamically generated button in C#

2 Answers 2

5 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

5 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related