Virtual Property
Specifies whether a Grid control allow virtual rows

Syntax:

Virtual <lValue>

This allows handling of millons rows without performance penalty.

When using virtual Grids you must avoid to use Item property and additem method. It can generate unexpected results.

Sample:

#include "hmg.ch"

Function Main

      DEFINE WINDOW Form_1 ;

            AT 0,0 ;

            WIDTH 450 ;

            HEIGHT 400 ;

            TITLE 'Hello World!' ;

            MAIN

            DEFINE MAIN MENU

                  DEFINE POPUP 'File'

                        MENUITEM 'Change ItemCount' ACTION Form_1.Grid_1.ItemCount := Val(InputBox('New Value','Change ItemCount'))

                  END POPUP

            END MENU

            @ 10,10 GRID Grid_1 ;

            WIDTH 400 ;

            HEIGHT 330 ;

            HEADERS {'Column 1','Column 2','Column 3'} ;

            WIDTHS {140,140,140};

            VIRTUAL ;

            ITEMCOUNT 100000000 ;

            ON QUERYDATA QueryTest()

      END WINDOW

      CENTER WINDOW Form_1

      ACTIVATE WINDOW Form_1

Return

Procedure QueryTest()

      This.QueryData := Str ( This.QueryRowIndex ) + ',' + Str ( This.QueryColIndex )

Return