APIs are library functions that the operating system provides developers to use for developing applications. The inside of the API function should be C C + + or assembly language implementation. If you want to use the API function inside the program needs to include the header file Windows.h. Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
The Windows operating system provides services externally through two interfaces: normal user Interface Services and programmer interface Services. The user interface service is done by the end user's operation, and the programmer Interface Service is to provide a series of basic functions (interfaces) that implement the operating system, which can be called by the programmer to accomplish the related functions.
For example, a copy of a file, the normal user can be selected by the Mouse menu operation or command to complete, the programmer can call the file operation through the program code related functions (API) to complete the same function.
All of these systems are underlying, implementing the most basic functions, and the functions that the programmer calls to form a set, which is the API (Applicationprogramming Interface).
Windows API programming is the best way to develop a Windows application that is the oldest, most primitive, and also the test of a programmer's mastery of the Windows operating system and related data structures.
It should be known that all of the other class libraries, and the later MFC, are encapsulated in the functions of these most basic functions.
Any functionality that can be implemented using MFC is also possible using the API and is more flexible. Learn about API programming and see what you can't see with MFC programming, learn more about Windows system operating mechanisms, and help us learn MFC programming.
The set of API functions is provided by the operating system or development environment and appears as a DLL.
There are three of the most important dynamic connection libraries: The Windows Kernel Library (Kernel32.dll), the Windows user Interface Management Library (User32.dll), the Windows Graphics Device Interface Library (Gdi32.dll),
These dynamic connection libraries together form the Win32 API function.
Windows Kernel Library (Kernel32.dll): all the underlying core functions such as task management, memory management, process thread file management, etc. are all in this dynamic connection library;
Windows user Interface Management library (User32.dll): Window Management, menu management, communication and other related functions are in the dynamic connection library;
Windows Graphics Device Interface Library (Gdi32.dll): A collection of all functions on a graphics device.
All of the function prototype descriptions in the three dynamic connection libraries are declared in the header file Windows.h, so don't forget to include the header file when using the API for programming.
Of course, this is only the main three dynamic connection library, other more commonly used network services (Winsock32.dll), multimedia Services (Winmm.dll) and so on.
The classification of  XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX  API functions. Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx1. Base services (base service), Provides the access interface to the underlying resources available to Windows systems. Examples include: file system, external device, process, thread, and access to the registry (Windows registry) and error-handling mechanisms (err handling). These feature interfaces are located in the Kernel.exe, Krnl286.exe, or krnl386.exe system documentation under 16-bit Windows, and in the Kernel32.dll and Advapi32.dll under 32-bit Windows. 2. Graphics Device Interface (GDI), which provides the ability to output graphics content to displays, printers, and other external output devices. It is located in Gdi.exe under 16-bit Windows, and Gdi32.dll under 32-bit Windows. 3. Graphical user interface (GUI), which provides the ability to create and manage screens and most basic controls, such as buttons and scroll bars. Receive mouse and keyboard input, as well as other GUI-related features. These call interfaces are located in User.exe under 16-bit Windows, and user32.dll under 32-bit Windows. From the Windows XP version, the calling interface of the basic control and the common dialog box control (Common control Library) is placed in Comctl32.dll. 4. Common Dialog link library (Common Dialog Box Library) provides standard dialog boxes for applications such as open/Save document dialogs, color dialogs, font dialogs, and so on. This library is located in Commdlg.dll under 16-bit Windows, and in 32-bit Windows under Comdlg32.dll. It is categorized under the user Interface API. 5. Universal Control link Library (Common Control Library) provides an interface for applications to access some of the advanced controls provided by the operating system. such as: status bar, progress bar (progress bars), Toolbars (toolbar), and Labels (tab). This link library is located in: 16-bit windoWS under Commctrl.dll, and 32-bit Windows under Comctl32.dll: It is categorized under the user Interface API. The 6.Windows shell (Windows shell), as part of the Windows API, not only allows applications to access the features provided by the Windows shell, but also improves and enhances them. It is located in Shell.dll under 16-bit Windows, and in Shell32.dll under 32-bit Windows (Windows 95 is in Shlwapi.dll). It is categorized under the user Interface API. 7. Network services, which provides interfaces for accessing the various network functions provided by the operating system. It includes NetBIOS, Winsock, NetDDE, RPC, and so on. Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Microsoft has encapsulated API functions in a framework library called MFC using the C + + language. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXC C + + can be Microsoft's operating system does not matter, so to speak of the operating system is C and C + + and a bit of assembly language son. Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
API for (GO) library functions
