Hello World – 3

Don’t worry ! This is the last; and important.

Extract DEFINE LABEL – END LABEL structure or @ …,… LABEL command ( which one is currently exist) and then instead of them place this line :

MsgBox( "Hello World !" )

In HMG, there are a lot of message functions, with name prefixed by “Msg“; for details please look at HMG Message Functions page.

After building and running, try a more important feature: reduce your program to these minimum size:

#include <hmg.ch>
PROCEDURE Main
   MsgBox( "Hello World !" )

RETURN // Main()

In fact, as a rule, every HMG project must have one and only one “Main” window. This message functions are exception of this rule. If you have only message function(s) you can build a program without main window.

Hello World – 2

In the our first example in first Quick Start page, we wrote the “Hello World” clause on the title bar. Now, let’s put it on the form.

Build a new project with “HelloWorld2” name, copy HelloWord.prg to HelloWorld2.prg and change it as below:

#include <hmg.ch>
PROCEDURE Main()
   DEFINE WINDOW frmHWLabel ;
      AT 0,0 ;
      WIDTH 400 ;
      HEIGHT 200 ;
      TITLE 'Hello World-2' ;
      MAIN 

      DEFINE LABEL lblHello
         ROW 75
         COL 125
         VALUE "Hello World !"
         FONTNAME "Lucida"
         FONTSIZE 16
      END LABEL

    END WINDOW 

    ACTIVATE WINDOW frmHWLabel

RETURN // Main()

DEFINE LABEL and END LABEL statements are for “Label” definition structure for the a window ( in this example Windows named as “frmHWLabel ” ). Label itself must have a name (“lblHello” in this example), and this name must be unique, such as a variable name. Beginning these names with a descriptive prefix ( “lbl” in the example) is a good programming practice.

Between DEFINE – END statements there are main properties of this label. Row, col numbers ( in pixels of course),value (for labels, value is a string constant to write in the your form/window) and font properties (NAME and SIZE)

Almost every GUI control definitions HMG have two syntax : With DEFINE and END structure and with @ command.Thus in the above example instead of DEFINE LABEL and END LABEL structure, you can use alternate @ syntax :

@ 75, 125 LABEL lblHello ;
          VALUE "Hello World !" ;
          FONT "Lucida" ; 
          SIZE 16

A last note for this example : place

CENTER WINDOW frmHWLabel

statementĀ END WINDOW statement and notice that how much HMG is powerful.

HelloWordLabel