Excuse me: What is the function of this sentence?

Source: Internet
Author: User
Excuse me: What is the function of this sentence? Delphi/Windows SDK/API
Http://www.delphi2007.net/DelphiBase/html/delphi_20061207130246245.html
A Program There are the following operations on window fmxx:
If not assigned (fmxx) then
Fmxx: = tfmxx. Create (Self) // (1) What is the function of this sentence?

Else
Exit;
Fmxx. show;

_____________________; // (2) what is required to release the occupied resources?
Fmxx: = NULL;


A program has the following operations on window fmxx:
If not assigned (fmxx) then
Fmxx: = tfmxx. Create (Self) // (1) What is the function of this sentence?

A: This is an instance for creating a class.
Fmxx: Class variable.
Tfrmxx. Create (Self); this is the class constructor. The parameter is the owner of the current instance. The owner is responsible for managing the memory space of the current instance.

Else
Exit;
Fmxx. show;

Fmxx. Free; // (2) what resources are required to be released here?
Fmxx: = NULL;

Thank you.

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.