MORE INFORMATION
Moving a Screen Object
Use _CUROBJ to move to a particular screen object. This object can even be
itself. You might want to do this in order to change the value of an
@...GET object while in that object's VALID clause.
The following example changes the value of x without leaving the @...GET.
When you set the value of _CUROBJ, try to avoid hard-coding an actual
number there because reordering fields in the Screen Builder can cause
unexpected results.
x = some_value
_CUROBJ = _CUROBJ
RETURN .T.
To avoid hard-coding a value, use an expression like:
_CUROBJ = OBJNUM(myvar)
Drives and Folders
Several FoxPro functions can be used to obtain information about drives and
folders. Compare the returned values after issuing the command SET DEFAULT
TO \FOXPRO.
? SYS(5)
MacHD:
? SET('DEFAULT')
MacHD:
? CURDIR()
\FOXPRO\
? SYS(2003)
\FOXPRO
? FULLPATH(SET('DEFA'))
MacHD:\
You can also use the ADIR() function to see if a specific folder exists.
Set Volume to Shorten Paths
You can use SET VOLUME to ease the task of typing long Macintosh folder and
path names.
For example, assume your Macintosh hard disk is named MacHD, and the
folders in which your files are located are MacHD:PICT files and
MacHD:Microsoft FoxPro:Project One. If you issue the following commands
SET VOLUME C TO "MacHD:Microsoft FoxPro:Project One"
SET VOLUME D TO "MacHD:PICT files"
whenever you use a command that specifies a file in these folders, you can
use the single-letter drive or volume designation. For example
COPY FILE D:GraphicImage.PIC TO C:
instead of
COPY FILE MacHD:PICT files:GraphicImage.PIC ;
TO MacHD:Microsoft FoxPro: Project One
The volume mapping can also be specified in your CONFIG.FPM configuration
file. For example, you can place the following lines in your CONFIG.FPM
configuration file:
VOLUME C = "MacHD:\Microsoft\FoxPro"
VOLUME D = "MacHD:\Microsoft\FoxPro\Project One"
VOLUME E = "MacHD:\PICT files"
DEFAULT = C:
Except for the colon following the Macintosh hard disk name, colons and
backslashes can both be used as delimiters in FoxPro for Macintosh. Note
that FoxPro for Macintosh does not recognize folder names containing
embedded back slashes (\).
For more information, see SET VOLUME.
USE Command
You can issue the command USE IN 0 to open a table in the first available
work area. This command does not select that work area in which it opened
the table. You must use the SELECT command to do this. You can issue the
command USE IN <alias> to close a table without selecting its work area.
The SHARE clause for the USE command allows you to open a table for shared
use without using the SET EXCLUSIVE command. For more information about the
USE command, refer to the USE topic.
Cross-Tab Output to Spreadsheets
Run the GENXTAB program to create cross-tabulated output that you can COPY
TO or EXPORT to a spreadsheet.
Custom Messages
You can display custom messages in the FoxPro status bar. To do this, SET
TALK OFF then use the SET MESSAGE TO <expC> command to specify a message.
(You can pass a null string to display nothing.) SET MESSAGE TO without a
parameter will restore the status bar to its normal functionality.
Preprocessor Directives
Do not use _WINDOWS, _DOS, _MAC, or _UNIX with preprocessor directives
(that is, #IF ... #ENDIF). These are designed to be runtime variables. For
example the following will not work:
#define _DOS .t.
#define _MAC .f.
* For code compile in MS-DOS, the following would not work:
DO CASE
CASE _DOS
? "Running in MS-DOS"
CASE _MAC
? "Running on Macintosh"
ENDCASE
This code would not work because _DOS would be changed to .T. and _MAC
would be changed to .F. so that the code could never work properly again.
Instead use the following:
#if "Win" $ VERS()
#define WINDOWS_CODE .t.
#elif "Mac" $ VERS()
#define MAC_CODE .t.
#elif "Unix" $ VERS()
#define UNIX_CODE .t.
#else
#define DOS_CODE .t.
#endif
#if WINDOWS_CODE
? "Compiled under WINDOWS"
#elif DOS_CODE
? "Compiled under DOS"
#endif
Prevent Preprocessor Substitution in Text Strings
#DEFINE prevents preprocessor substitution in text strings. Note that
square brackets [ ] can be used do delimit text strings. This means that no
substitution will be made in the following:
#DEFINE nosub 1
DECLARE an_array(3)
*** This will cause a 'variable NOSUB not found' error
*** because no substitution was made
? afunc[an_array[nosub]]
FUNCTION afunc
PARAMETER x
RETURN x
Development Tools
The FOXTOOLS.MLB file, which is located in your Systems:Extensions folder,
contains a variety of functions that you can use to enhance your
applications. Many of these functions provide access to API routines and
Macintosh functions. You can view these using the DISPLAY STATUS command
(after you issue SET LIBRARY TO foxtools).