eof( ) 函数示例

下面的示例打开 customer 表并显示带有命令按钮的窗口，可用此命令按钮在表中向前或向后移动记录指针。随着记录指针移动方向的不同，visual foxpro 将检查记录指针是否指向文件尾 (eof)，或是否指向文件头 (bof)。当任一条件为“真”(.t.) 时，visual foxpro 将显示相应的信息并重定位记录指针。

close databases
open database (home( ) + 'samples\data\testdata')
use customer && 打开 customer 表
set talk off
clear
activate screen
@ 2,1 say 'company: '+ company
define window wskip from 9,10 to 14,65 double color scheme 5
activate window wskip
@ 1,5 get gnchoice function '*hn \<forward;\<backward;\<quit' ;
default 0 size 2,14 valid choice( )
read cycle
release window wskip

procedure choice
do case
case gnchoice = 1
skip
if eof('customer')
wait window 'end of file encountered' nowait
skip -1
endif
case gnchoice = 2
skip -1
if bof('customer')
wait window 'beginning of file encountered' nowait
go top
endif
case gnchoice = 3
clear read
endcase
activate screen
@ 2,1 clear to 2,50

@ 2,1 say 'company: '+ company
return .t.