Itemid (ScreenField property): Difference between revisions

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This property sets or returns a numeric item ID value for a ScreenField. This ID is initially set for a field by the [[Screen class#AddField function|AddField method]].
This property sets or returns a numeric item ID value for a ScreenField. This ID is initially set for a field by the [[Screen class#AddField function|AddField method]].
==Syntax==
===Syntax terms===
<dl>
<dt>num
<dd>An integral numeric variable or expression, which can range from 1 to 32767.
<dt>%sfield
<dd>A reference to an instance of a ScreenField object.
</dl>


  %sfield:Itemid = num
==Usage Notes==
  num = %sfield:Itemid
 
; Itemid syntax
 
; num
: An integral numeric variable or expression, which can range from 1 to 32767.
 
: %sfield
: A reference to an instance of a ScreenField object.
 
; Usage Notes


Any screenfield can be assigned an item ID.
Any screenfield can be assigned an item ID.

Revision as of 20:21, 18 March 2011

This property sets or returns a numeric item ID value for a ScreenField. This ID is initially set for a field by the AddField method.

Syntax

Syntax terms

num
An integral numeric variable or expression, which can range from 1 to 32767.
%sfield
A reference to an instance of a ScreenField object.

Usage Notes

Any screenfield can be assigned an item ID.

An item ID is very practical when using arraylists of screenfields. ScreenField objects within an arraylist can be assigned item IDs corresponding to the element numbers of the arraylist. For example, the Screen method CursorItemId will return the item ID of the screenField object where the cursor is positioned. The item ID can then be used as the element number to reference a ScreenField object within an arraylist.

Any screenField not assigned an item ID value will return zero. No check is made to ensure any item Id is unique. This is the programmer's responsibility.