wnoutrefresh.3cur

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3CUR 代码 · 共 72 行

.TH wnoutrefresh 3cur 
.SH Name
wnoutrefresh, doupdate \- do efficient refresh
.SH Syntax
.br
.B
#include <cursesX.h>
.PP
.br
.B
int wnoutrefresh(win)
.br
.B
WINDOW \(**win;
.PP
.B
int doupdate(\|)
.SH Description
.NXR "wnoutrefresh subroutine"
.NXR "doupdate subroutine"
.NXA "wrefresh subroutine" "wnoutrefresh subroutine"
The
.PN wnoutrefresh
routine
updates screens more efficiently than using the
.PN wrefresh 
routine by itself.
The 
.PN wnoutrefresh
routine
copies the named window to a data structure referred to as
the virtual 
screen (stdscr).
The virtual screen contains what a program intends to display
on the physical terminal screen.
The routine
.PN doupdate 
compares the virtual screen to the physical screen and then does the actual update.
These two routines allow multiple updates with more efficiency than 
.PN wrefresh .
.PP
The routine 
.PN wrefresh 
works by calling 
.PN wnoutrefresh ,
and then calling 
.PN doupdate .
If a programmer wants to output several windows at once, 
a series of calls to 
.PN wrefresh 
will result in alternating calls to 
.PN wnoutrefresh
and 
.PN doupdate ,
causing several bursts of output to the screen.
If 
.PN wnoutrefresh
is called first for each window, 
.PN doupdate 
only needs to be called 
once, resulting in only one burst of output.
This usually results in fewer total
characters being transmitted and less CPU time used.
.SH Return Values
The
.PN doupdate
and
.PN wnoutrefresh
functions return OK on success and ERR on error.
.SH See Also
wrefresh(3cur)