OnGUI and Displaying GUI Features

Ok right now I have a vague beginnings of my UI. The buttons get added to the scroll area and then track each button clicked, in order to open a GUI.Window item which I haven't implemented yet.

void OnGUI()
{    

    AutoItemLayout();
    for (int i = 0; i < buttons.Count; i++)
    {
        if (buttons*)*
 *{* 
 *//do something* 
 *}*
 *}*
*}*
*void AutoItemLayout()*
*{*
 *GUI.enabled = windowNotOpen;*
 *GUILayout.BeginArea(new Rect(0, 0, SHOP_WIDTH, SHOP_HEIGHT));*
 *GUI.Box(new Rect(0, 0, SHOP_WIDTH, SHOP_HEIGHT), "");* 
 *category = GUI.Toolbar(new Rect(5, 5, SHOP_WIDTH - 10, 85), category, categoryName);* 
 *GUI.Box(new Rect(5, 95, (SHOP_WIDTH - 10), (SHOP_HEIGHT - 100)), "");*
 *scrollViewVector = GUI.BeginScrollView(new Rect(10, 100, (SHOP_WIDTH - 20), (SHOP_HEIGHT - 110)), scrollViewVector, new Rect(0, 0, 0, scrollHeight));*
 *if (category != currentCategory)*
 *{*
 *buttons.Clear();*
 *switch (category)*
 *{*
 *case 0:*
 *displayItems = clothes;*
 *currentCategory = 0;* 
 *break;*
 *case 1:*
 *displayItems = playground;*
 *currentCategory = 1;* 
 *break;*
 *case 2:*
 *displayItems = music;*
 *currentCategory = 2;* 
 *break;*
 *case 3:*
 *displayItems = zopet;*
 *currentCategory = 3;* 
 *break;*
 *default:*
 *Debug.Log("SHOP TOOLBAR BROKE");*
 *break;*
 *}*
 *setUpShopLayout();* 
 *for (int i = 0; i < buttonPositions.Count; i++)*
 *{*
 <em>buttons.Add(GUI.Button(buttonPositions_, displayItems*.ItemName));*_</em>
 <em>_*}*_</em> 
 <em>_*}*_</em> 
 <em>_*GUI.EndScrollView();*_</em>
 <em>_*GUILayout.EndArea();*_</em>
 <em>_*GUI.enabled = true;*_</em>
<em>_*}*_</em>
<em>_*public void setUpShopLayout()*_</em>
<em>_*{*_</em>
 <em>_*buttonPositions.Clear();*_</em>
 <em>_*count = 0;*_</em>
 <em>_*noExtraItems = true;*_</em>
 <em>_*total = displayItems.Count;*_</em>
 <em><em>*lessThan = (int)(SHOP_WIDTH - 35) / (buttonWidth); ;*</em></em>
 <em><em><em>buttonBuffer = (int)(SHOP_WIDTH - 35 - (buttonWidth * lessThan)) / lessThan;</em></em></em>
 <em><em>_scrollHeight = ((total / lessThan) * (buttonHeight + buttonBuffer));_</em></em>
 <em>_*numrows = total / lessThan;*_</em>
 <em>_*if ((total % lessThan) > 0)*_</em>
 <em>_*{*_</em>
 <em>_*extraItems = total % lessThan;*_</em>
 <em>_*numrows++;*_</em>
 <em>_*scrollHeight = scrollHeight + (buttonHeight + buttonBuffer);*_</em>
 <em>_*noExtraItems = false;*_</em>
 <em>_*}*_</em>
 <em>_*for (int i = 0; i < (numrows); i++)*_</em>
 <em>_*{*_</em>
 <em>_*if ((i + 1) < numrows || noExtraItems)*_</em>
 <em>_*{*_</em>
 <em>_*for (int j = 0; j < lessThan; j++)*_</em>
 <em>_*{*_</em>
 <em>_*name = displayItems[count].ItemName;*_</em>
 <em><em>_buttonPositions.Add(new Rect((j * (buttonWidth + buttonBuffer)), (i * (buttonHeight + buttonBuffer)), buttonWidth, buttonHeight));_</em></em>
 <em>_*count++;*_</em>
 <em>_*}*_</em>
 <em>_*}*_</em>
 <em>_*else*_</em>
 <em>_*{*_</em>
 <em>_*for (int j = 0; j < extraItems; j++)*_</em>
 <em>_*{*_</em>
 <em>_*name = displayItems[count].ItemName;*_</em>
 <em><em>_buttonPositions.Add(new Rect((j * (buttonWidth + buttonBuffer)), (i * (buttonHeight + buttonBuffer)), buttonWidth, buttonHeight));_</em></em>
 <em>_*count++;*_</em>
 <em>_*}*_</em>
 <em>_*}*_</em>
 <em>_*}*_</em>
<em>_*}*_</em>
<em>_*```*_</em>
<em>_*<p>That's the main chunk of my code.  However the loop, that adds the GUI.Button to the buttons array, is infinity adding buttons outside of the if(category != currentCategory) statement, and inside the if statement it adds the correct number of buttons, however they do not appear on the UI.  Any ideas?</p>*_</em>
<em>_*<p>Thanks,*_</em> 
<em>_*Hans*_</em>
<em>_*Unity Newb</p>*_</em>

Unity uses an immediate GUI system. That means ObGUI is called every frame and you have to draw your GUI every frame. You can't create a GUI and just display it. At the moment you stop calling GUI.Button() the button will disappear.

Also take a look at GUILayout that provides the same elements as GUI but the size and position is determined automatically. You can use horizontal or vertical groups to design your layout. Those groups can be nested. With GUILayoutOptions like Width you still can influence the layouting