Rockwell-automation 2708-NBD VBASIC Language Development Kit Manual de usuario descargar pdf (Pagina 75)

Appendix C

Application Library Subroutines

C–7

The global MODIFIED% is TRUE when the string was changed in any

way. The strlength is the maximum number of characters to allow in the

string (not including the terminal null). This must be at least fieldlength%

characters long. The return value “e” is an event code. This is 0 on a normal

return (operator pressed CR). The devices which are active are defined by the

global variable GLOBALMASK% which is in the same format as the

mask% used by % and TestEvent%. The field will start at the current cursor

location. The cursor is left at its starting locationi when ReadStrField exits.

e = ReadStrField%( attr%, fldlen%, strtchar%, string$,

stringlen% )

FUNCTION ReadStrField% ( attr%, flength%, strpos%, s$,

slen% )

ReadStr% Edit a string on the screen.

Thhis is a simplified version of ReadStrField% that does not have as many

parameters. Any attributes should be in the GLOBALATTR% variable.

Don’t forget to set GLOBALMASK% to the devices which can terminate the

read. Make sure you include KbdMask. See TestEvent% for more info.

e = ReadStr ( length%, s$ )

FUNCTION ReadStr% ( n%, s$ )

An example of reading from the keyboard is as follows:

e = ReadStr(Length%, s$)

IF e = BadgeEvent THEN

s$ = InBuf$. .

END IF

ReadNumStr% Edit a numeric string on the screen.

The string which is edited may contain only 0 through 9. Any attributes

should be in the GLOBALATTR% variable.

e = ReadNumStr ( length%, s$ )

FUNCTION ReadNumStr% ( n%, s$ )

ReadYN% Wait for a YES/NO response from user.

Returns TRUE or FALSE depending on the user’s response. EXITKEY% is

set if you really need the event value. Nothing is displayed; this just waits for

Enter, Clear, or a Y or N.

IF ReadYN% ( default% ) THEN . . .

FUNCTION ReadYN% ( defv% )

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Rockwell-automation 2708-NBD VBASIC Language Development Kit Manual de usuario Pagina 75