National Instruments Window, User Manual

LabWindows/CVI Release Notes for Windows

18

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 National Instruments Corporation

By using direct Windows printing, you can take full advantage of the higher resolution 
printers have over computer screens. This allows panels and controls to be scaled optimally 
to the printer coordinates, thus eliminating the aliasing that causes blocky text and graph 
plots. On the other hand, certain printers do not support the raster operations necessary for 
printing certain kinds of objects. Specifically, many printers are not capable of printing 
transparent bitmaps.

Revised Print Dialog Boxes on Windows

For programmatic printing and printing from the File menu, a common, unified print dialog 
box allows you to do the following:

•

Select a printer.

•

Specify printing options that are specific to LabWindows/CVI. Different sets of options 
appear for graphics printing as opposed to text printing. 

•

Open the standard Windows dialog box for the selected printer. You set options that are 
specific to the printer in this dialog box. 

You can programmatically set all the options that are specific to LabWindows/CVI by using 

SetPrintAttribute

 in LabWindows/CVI. In addition, you can programmatically set some 

of the attributes in the printer-specific dialog box using 

SetPrintAttribute

.

Interaction between Print Dialog Boxes and Programmatic Attributes

LabWindows/CVI 5.0 modifies the way the print dialog boxes interact with attributes when 
used in a program. 

Previously, if you selected a different printer in the dialog box, the User Interface Library 
did not retain the name of the selected printer. Every time the print dialog box appeared, 
the printer selection was reset to the current system printer. Now, the library stores the 
name of the printer you select in a new attribute, 

ATTR_PRINTER_NAME

. Whenever the print 

dialog box appears, LabWindows/CVI sets the printer selection to the current value of 

ATTR_PRINTER_NAME

. If 

ATTR_PRINTER_NAME

 is 

NULL

, the empty string, or the name of a 

printer that is not currently known by Windows, the next call to a printing function uses the 
current system printer and stores its name as the 

ATTR_PRINTER_NAME

 value. 

Normally, when the user invokes the common print dialog box or the printer-specific dialog 
box, LabWindows/CVI initializes the controls that correspond to programmatic attributes to

the current attribute values. The new value 

VAL_USE_PRINTER_SETTING

 allows you to 

initialize the printer-specific dialog box to the current system values for the printer rather 
than the current values of the User Interface Library attributes. You can access the system 
values for the printer in the Control Panel. When the user clicks on OK in the dialog box, 
LabWindows/CVI copies the current values in the controls to the attributes. 
LabWindows/CVI does not retain the 

VAL_USE_PRINTER_SETTING

 value.

Refer to the following 

Using Windows System Printer Settings

 section for more information 

on 

VAL_USE_PRINTER_SETTING

.