C# Get total inside area of scrollable panel

Should be a nice easy one for someone...

I have a panel which I am dynamically adding child controls to, to the point where scroll bars will appear when any of them are placed outside of the visible area.

I need to know the total size of this area. i.e. how wide the scrollable area is?

I could get the furthest placed control and use its left + width properties, but there must be a cleaner way?

Edit: Hopefully this illustrates what I need (Scrollable area width). enter image description here

Solution

Try with this

SystemInformation.VerticalScrollBarArrowWidth

see http://msdn.microsoft.com/en-us/library/system.windows.forms.systeminformation.verticalscrollbarwidth.aspx