Create controls in loop

SAKryukov, thank You for your answer. The deal with creating controls on each step of loop, is that it gets heavy and it hangs when i try to add 90 groupboxes with two checkboxes in each of it. So it's 270 controls in one loop, and it consumes 25% of my cpu (a quad core) for about a minute.

Do you have any better idea, to make it happen faster?

Sorry, I'm not interested in improving performance of application which creates 600 controls. Why? Nobody will look at more than ten (to many two tens) active controls at a time. If you insist on so many controls, you'll have to explain the purpose, because this thing would be way too exotic.

So, if you're ready to re-design into more reasonable/practical approach, here is what you can do:

You need to structure design of you mass of controls into some "chapters", "sub-chapters"... into some hierarchy of reasonable depth. Each chapter goes in separate panel, but you should not ever create all 666 ;) controls. Only one chapter should be visible at a time, each containing limited observable an usable number of controls. You need only one panel, but controls are removed and re-populated each time you navigate (see below) to a chapter of interest.

How to navigate? On your main window left, imagine a control that behaves like Table of Contents (TOC). Most general view would provide a TreeView, a simple one (1-level hierarchy) -- a list box. On this control, you navigate from item to item each representing a chapter. Setup event handler OnSelectionChanged: it should clean the panel on your right and repopulate it with new set of controls.

What to put in tree view?

You need something that would be represented as a string, at the same time the item type should carry data on control set on your right. The way to resolve this is some structure with overridden object.ToString:

struct ItemInfo {
    internal ItemInfo(string name /* something else ... */) { Name = name; }
    public override string ToString() {
        return Name.ToString();
    } //ToString
    string Name;
    //whatever else
    //...
} //struct ItemInfo

Now, you need to populate your TOC control with items of the type ItemInfo:

//...
string name = //...
ItemInfo info = new ItemInfo(name);
box.Items.Add(info);
//...

When you handle OnSelectionChanged, you know that you can downcast you item's Content to ItemInfo.

Develop population procedure like CreatePageControls(ref ItemInfo info) and call it from your handler of OnSelectionChanged.

Now, as you show only few controls at a time, any performance will be sufficient (on UI event, one millisecond does not count).

To give you an idea of another look at this: are you familiar with virtual container controls and/or virtual mode of controls such as grid views or list views? You can think of the design I describe as of a virtual-mode container. Alternatively, you can make more general solution using virtual container controlled by, say, a scroll bar. A scroll bar can show 900 thousands of virtual items, with only a small part of them existing physically at the same time: only those in the visible part of scrollable area plus as many down and up of this place, for better cashing.

How about that?