How can i draw a gauge bar during a tquery.open session? I know the record
count of the table (=100%), but how can i get the actual record, which tquery
is processing? how can i operate during running query?
Answer
A:
Not possible.
没有可能!!
The idea behind the TQuery object is to have a SQL server process the
request in the background and take the local machine completely out of
the loop. The app is never supposed to know what the TQuery is doing,
so a gauge that measures progress would have to get its data from a
SQL server. Since most SQL servers dont publish this info, you are
probably out of luck on this one...
A:
If you're using Paradox or DBase I think you can use the
如果你是使用 Paradox 或者 DBase,我想你可以使用DBIRegisterCallback凾数
DBIRegisterCallback function
>From the DBE users manual:
Usage:
Callbacks are used when a client application needs clarification about a given
engine function before completing an operation or to return information to the
client. DBIRegisterCallback allows the client to instruct the database engine
about what further actions should be taken by the engine upon occurence of an
event.
I've never used it before, so I can't give you the details.