National Instruments Window, Руководство пользователя

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© National Instruments Corporation 19 LabWindows/CVI Release Notes for Windows
Using Windows System Printer Settings
VAL_USE_PRINTER_SETTING
applies to all print attributes for which corresponding
Windows system settings exist. You can view and modify the Windows system settings for a
printer in the Control Panel. The
VAL_USE_PRINTER_SETTING
value allows you to use the
current settings of the operating system instead of the current values of the User Interface
Library attributes.
If you call one of the printing functions
PrintCtrl
,
PrintPanel
,
PrintTextBuffer
, or
PrintTextFile
and an attribute value is
VAL_USE_PRINTER_SETTING
, LabWindows/CVI
changes the attribute value to the current system setting. The exact behavior depends on
whether you instruct the printing function to invoke the print dialog box. Notice that only
PrintCtrl
and
PrintPanel
give you the option to open the dialog box:
• If the function invokes the common print dialog box and the user invokes the
printer-specific dialog box, LabWindows/CVI initializes the control that corresponds to
the attribute to the current system setting. The user can modify the value. When the user
clicks on OK in the printer-specific dialog box, LabWindows/CVI stores the current
value of the control as the attribute value.
• If the function invokes the common print dialog box but the user never invokes the
printer-specific dialog box, LabWindows/CVI stores the system setting as the attribute
value when the user clicks on OK in the common dialog box.
• If you suppress the dialog boxes, the print function uses the current system setting and
stores it as the attribute value.
Notice that LabWindows/CVI does not retain
VAL_USE_PRINTER_SETTING
as the attribute
value after you call a printing function. If, throughout the life of your program, you want to
use the system settings that are in effect the first time you call a printing function, set the
attributes to
VAL_USE_PRINTER_SETTING
at the beginning of your program and do not
modify them programmatically thereafter. If, on the other hand, you always want to use the
most recent system settings, you must set the attributes to
VAL_USE_PRINTER_SETTING
before each call to a printing function.
You can use
VAL_USE_PRINTER_SETTING
with the following attributes:
•
ATTR_DUPLEX
•
ATTR_NUMCOPIES
•
ATTR_ORIENTATION
•
ATTR_XRESOLUTION
•
ATTR_YRESOLUTION
Note The User Interface Library never changes the current system printer or the
current system settings for a printer.