Delphi 判断文件是否被占用，这个在删除的时候，可以添加上此功能，因为文件占用的话，用户删除时会出错，用本代码可以先判断一下文件是否被占用，用弹窗方式告诉用户是否可以删除，如果没有被占用，则程序进行下一步处理。下面简要了解一下判断的具体代码（局部）：
on E:EInOutError do
begin
if e.ErrorCode=32 then//文件正在被使用
begin
result:=true;
exit;
end;
end;
更完整的可编译源码，请下载。
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001999s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.089162s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.005637s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.002115s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.002474s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.005472s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.002714s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.005621s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.024395s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.003162s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 293952 [ RunTime:0.001446s ]
