HP 40gs HP 39gs_40gs_Mastering The Graphing Calculator_English_E_F2224-90010.p - Page 264

Msg.sv, Views, Message Symbolic View, Program Catalog, Aplet, Enter, Msgbox, Setviews

Page 264 highlights

Having created all of the programs that make up the aplet 'Message', we can now run the program .MSG.SV, severing the aplet's link to its current VIEWS menu which was inherited from its parent the Function aplet, and substituting this new menu. Before you do this, check that you are still in the correct aplet. Press the SYMB key and check that the title at the top still says "MESSAGE SYMBOLIC VIEW". If it doesn't show this, then the aplet again to ensure that it is the active one and so the one whose VIEWS menu will be changed. This step is critical - you do not want to change the VIEWS menu for the wrong aplet! Swap back to the Program Catalog, position the highlight on the program .MSG.SV and the program. Apart from the screen going blank for a moment nothing will appear to happen, but in fact the link to the normal VIEWS menu which 'Message' inherited from its parent aplet Function has been severed and a link to the new menu you built in .MSG.SV has been substituted. Press VIEWS to check. You should find that your new menu appears. Press to exit. Providing that you have done everything correctly, this is now the end of the process - the aplet is now ready to be run. In the APLET view, make sure the highlight is still on the aplet and press or ENTER to run it. If you get an error message at any time then you may have to and the program. When you do this, the aplet will run the program .MSG.S which will display a MSGBOX. The line in the SETVIEWS command controlling this was: "Start";".MSG.S";7; Since the triplet ends with a view number of 7, this means that after the program terminates (when you press ), the VIEWS menu will display. If you choose the option 'Message 1', then this will cause the program .MSG.1 to be run, displaying the screen on the right. This line in the SETVIEWS command also terminated with a view number of 7 so when you press the VIEWS menu will display again. The program line for this was: MSGBOX "Hello world! 3+4 = " 3+4: Items in quotes are displayed as they appear, while expressions outside them are evaluated before being displayed. This means that the 3+4 inside the quotes appears as exactly that, while the one outside is evaluated to 7. Expressions can include variables and calls to functions. 264

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Having created all of the programs that make up the aplet ‘Message’, we can now run the program
.MSG.SV
, severing the aplet’s link to its current
VIEWS
menu which was inherited from its parent the Function
aplet, and substituting this new menu.
Before you do this
, check that you are still in the correct aplet.
Press
the
SYMB
key and check that the title at the top still says “
MESSAGE SYMBOLIC VIEW
”. If it doesn’t show
this, then
the aplet again to ensure that it is the active one and so the one whose
VIEWS
menu will be
changed.
This step is critical – you do not want to change the
VIEWS
menu for the wrong aplet!
Swap back to the
Program Catalog
, position the highlight on the program
.MSG.SV
and
the
program. Apart from the screen going blank for a moment nothing will appear to happen, but in fact the link
to the normal
VIEWS
menu which ‘Message’ inherited from its parent aplet Function has been severed and a
link to the new menu you built in
.MSG.SV
has been substituted.
Press
VIEWS
to check.
You should find that
your new menu appears. Press
to exit.
Providing that you have done everything correctly, this is now the end of the process - the aplet is now ready
to be run.
In the
APLET
view, make sure the highlight is still on the aplet and press
or
ENTER
to run
it. If you get an error message at any time then you may have to
and
the program.
When you do this, the aplet will run the program
.MSG.S
which will
display a
MSGBOX
.
The line in the
SETVIEWS
command controlling this was:
"Start";".MSG.S";7;
Since the triplet ends with a view number of 7, this means that after the
program terminates (when you press
), the
VIEWS
menu will
display.
If you choose the option ‘Message 1’, then this will cause the program
.MSG.1
to be run, displaying the screen on the right.
This line in the
SETVIEWS
command also terminated with a view number of 7 so when
you press
the
VIEWS
menu will display again.
The program line for this was:
MSGBOX "Hello world! 3+4 = " 3+4:
Items in quotes are displayed as they appear, while expressions outside them are evaluated before being
displayed. This means that the 3+4 inside the quotes appears as exactly that, while the one outside is
evaluated to 7. Expressions can include variables and calls to functions.
264