Shulou(Shulou.com)06/03 Report--

This article will explain in detail the usefulness of handles in C++. The editor thinks it is very practical, so I share it with you as a reference. I hope you can get something after reading this article.

A Handle is an identifier that identifies an object or item and can be used to describe forms, files, and so on. It is worth noting that a handle cannot be a constant. The reason why Windows wants to set up a handle fundamentally stems from the problem of memory management mechanism, that is, virtual address. In short, the address of the data needs to be changed, and after the change, someone is needed to record and manage the change, so the system uses a handle to record the change of the data address. In programming, a handle is a special intelligent pointer, which is used when an application wants to reference a block or object of memory managed by another system (such as database, operating system).

An introduction to the handle

Handle is a term often mentioned in C++ programming. It is not a specific, fixed data type or entity, but represents a broad concept in programming. A handle generally refers to a method of getting another object-a generalized pointer, which may be in the form of an integer, an object, or a real pointer, and its purpose is to establish the only relationship with the object being accessed.

In C++, to access an object, you can usually establish a pointer to the object. However, in many specific applications, directly using pointers to represent objects is not a good solution.

Object

A handle is the identification of objects or instances in a Windows system, including modules, application instances, windows, controls, bitmaps, GDI objects, resources, files, and so on.

Handle data type

In terms of data type, it is just a 16-bit unsigned integer. Applications always get a handle by calling WindowsAPI, which can then be used by other Windows functions to reference and manipulate the corresponding kernel object. The handle can be left empty like a pointer, so that the handle does not make any sense and does not represent any kernel object.

Handle is a very important concept in Windows programming. In Windows programs, physical addresses are not used to identify a memory block, file, task, or dynamically loaded module. Instead, WindowsAPI assigns a definite handle to these items, returns the handle to the application, and then operates through the handle.

It should be understood that a handle is an identifier that identifies an object or project. In terms of data type, it is just a 16-bit unsigned integer. Applications almost always get a handle by calling a Windows function, which can then be used by other Windows functions to reference the corresponding object. A large number of handles are used in Windows programming.

This is the end of the article on "what's the use of handles in C++?". I hope the above content can be helpful to you, so that you can learn more knowledge. if you think the article is good, please share it for more people to see.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.