foreach list always uses last value

Try this:

foreach(Button button in Buttons)
{
    Button b = button; // add this to "copy" the current button
    b.update(activeMouse);
}

Show the code that adds the buttons to the list. I suspect that you aren't allocating a new instance for each button, but are reusing a single button instance.

@tharealjohn - that code would make no difference at all.

@tharealjohn I had already tried that as well as a regular for loop to no avail.

@Dave Hunt

Edit: Notcied the Button constructor was missing the arguments.

This is how I add a button (inside of a method);

Button button = new Button(this, rectangle, title);
Buttons.Add(button);

I think we'll need to see the constructor and the update method for your Button class.

The Button constructor:

        public Button(Object obj, Rectangle relativeRectangle, string title)
            : base()
        {
            Rectangle = obj.Rectangle;
            RelativeRectangle = relativeRectangle;
            Visible = true;
            Title = title;
        }

and the update method:

        public void Update(Object obj, Mouse activeMouse)
        {
            Rectangle = obj.Rectangle;
            base.Update(activeMouse);
        }

Deeper and deeper...

The code that actually uses the mouse information and updates the button's text appears to be somewhere in a base class. That's the code we need to see.

Also, the code you show for calling Button.Update doesn't match the signature of the Button.Update method. Your Button.Update method takes an Object and a Mouse, but your calling function only shows passing a Mouse...

Fixed the update call in the foreach (no change). The base update code is as follows:

public void Update(Mouse activeMouse)
        {
            bool intersect = activeMouse.Rectangle.Intersects(Rectangle);

            if (intersect || (ActiveMouse != null && (LeftState != ObjectClickedState.Normal || RightState != ObjectClickedState.Normal)))
            {
                ActiveMouse = activeMouse;
                ActiveMouse.ClickedObject = this;
                if (intersect)
                    OnHover();
                if (ActiveMouse.LeftPress && (LeftState == ObjectClickedState.Normal || LeftState == ObjectClickedState.Released))
                {
                    LeftState = ObjectClickedState.Clicked;
                    OnLeftClick();
                }
                else if (ActiveMouse.LeftPress && LeftState == ObjectClickedState.Clicked)
                    OnLeftPress();
                else if (ActiveMouse.LeftRelease && LeftState == ObjectClickedState.Clicked)
                {
                    LeftState = ObjectClickedState.Released;
                    OnLeftRelease();
                }
                else if (!ActiveMouse.LeftPress && LeftState == ObjectClickedState.Released)
                {
                    LeftState = ObjectClickedState.Normal;
                    OnLeftNormal();
                }

                if (ActiveMouse.RightPress && (RightState == ObjectClickedState.Normal || RightState == ObjectClickedState.Released))
                {
                    RightState = ObjectClickedState.Clicked;
                    OnRightClick();
                }
                else if (ActiveMouse.RightPress && RightState == ObjectClickedState.Clicked)
                    OnRightPress();
                else if (ActiveMouse.RightRelease && RightState == ObjectClickedState.Clicked)
                {
                    RightState = ObjectClickedState.Released;
                    OnRightRelease();
                }
                else if (!ActiveMouse.RightPress && RightState == ObjectClickedState.Released)
                {
                    RightState = ObjectClickedState.Normal;
                    OnRightNormal();
                }
            }
            else
            {
                if (ActiveMouse != null)
                {
                    ActiveMouse.ClickedObject = null;
                    ActiveMouse = null;
                    OnLeave();
                }
            }
        }

Is Mouse a struct or a class? If it's a class, then all the changes you make to ActiveMouse are actually changing the values in activeMouse that gets passed on to the Update methods for all the rest of the buttons. That might explain why subsequent buttons think they've been clicked.

It's a class. Is there any way to fix that while keeping the mouse object the same for each button?

Not really. Unless your Button class really needs everything in the Mouse class, I would suggest just extracting the values you need and storing them individually in the Button.

I was thinking it could be a Closure problem. Perhaps it's not. Sorry for the mislead.

@tharealjohn - that code would make no difference at all.

I was thinking it could have been a Closure issue. Perhaps its not, sorry for the misleading information.

@Dave Hunt: You have been tremendously helpful, thank you so much. Sorry to ask one more thing, but is there any chance you could show me an example of that? I tried to do so on my own but I got nowhere.

@tharealjohn: No problem man, thanks for the help regardless =)