Hi:

 How can I print bar  code .(use printer)

The easiest option is to use a commercially-available bar code font.

But you should be very careful-- if you are talking about bar codes for
consumer packaging, for instance, you are assuming a huge liability risk.  I
work on software which creates consumer product packaging, and we have
chosen not to support bar codes for that reason.

You see if they don't work perfectly on all bar-code scanners, you run the
risk of being sued by merchants who then have to manually enter the bar code
information at the checkstand for every sale.

If you are talking about something for use just in-house, or with a barcode
scanner you supply with your software, then you are probably safe.

There are a number of different international barcode standards.  Check them
out.  There's usually a bar code font for each different type.

Cheers,
Mike