The underlying API of windows is written by C language, and MFC is encapsulated by C + +.
If you want to program with MFC, you have to start with the main method
The main function C of MFC is written as
Warm tip: if the function variable name has p, it is generally the pointer and the address when entering the parameter
#include <Windows.h>
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,LPTSTR lpCmdLine, int nShowCmd) {
// Main program content...
}
The following is the writing method of c + +
#include <Windows.h>
extern "C" int WINAPI _tWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,LPTSTR lpCmdLine, int nShowCmd) {
// Main program content...
}
It should be noted that MFC functions have to add macro definitions. WINAPI indicates the transfer order of parameters. Parameters are stacked from right to left, and the function stack is cleared before function return
- hInstance current music instance handle
- The handle of a music program on hPrevInstance is generally NULL in win32 environment
- lpCmdLine type LPTSTR is equivalent to char* args []
- nShowCmd displays the commands maximize, minimize, and normal
The main program is divided into one window
- Design window
- Registration window
- create a window
- Display and update
- Loop get message
- Processing messages
1, Design a window
In fact, windows has encapsulated the window into a structure WNDCLASS. We only need to supplement the content of this structure and set the information of a window class.
After adjusting the macro definition, you will find that the structure has the following contents
There is no additional explanation for repeated contents
typedef struct tagWNDCLASSA {
UINT style;
WNDPROC lpfnWndProc;
int cbClsExtra;
int cbWndExtra;
HINSTANCE hInstance;
HICON hIcon;
HCURSOR hCursor;
HBRUSH hbrBackground;
LPCSTR lpszMenuName;
LPCSTR lpszClassName;
} WNDCLASSA, *PWNDCLASSA, NEAR *NPWNDCLASSA, FAR *LPWNDCLASSA;
typedef struct tagWNDCLASSW {
UINT style; // Display style (maximize, minimize, 0 is the default)
WNDPROC lpfnWndProc;// ==>Callback function of window procedure (message callback)
int cbClsExtra; // Class
int cbWndExtra; // Window extra memory
HINSTANCE hInstance; // Application Instance Handle
HICON hIcon; // Icon above window
HCURSOR hCursor; // Cursor, WC hCursor = LoadCursor(NULL,IDC_HAND); The first parameter is null, indicating the use of the system cursor, and the second parameter indicates the shape of the mouse (pointer, small hand, etc.)
HBRUSH hbrBackground; // Background, generally use white brush (HBRUSH) GetStockObject(WHITE_BRUSH);
LPCWSTR lpszMenuName; // Specifies the name of the window class
LPCWSTR lpszClassName; // Specify the proper name
} WNDCLASSW, *PWNDCLASSW, NEAR *NPWNDCLASSW, FAR *LPWNDCLASSW;
#ifdef UNICODE
typedef WNDCLASSW WNDCLASS;
typedef PWNDCLASSW PWNDCLASS;
typedef NPWNDCLASSW NPWNDCLASS;
typedef LPWNDCLASSW LPWNDCLASS;
#else
typedef WNDCLASSA WNDCLASS;
typedef PWNDCLASSA PWNDCLASS;
typedef NPWNDCLASSA NPWNDCLASS;
typedef LPWNDCLASSA LPWNDCLASS;
#endif // UNICODE
2, Registration window
Warm tip: when calling API, you will find that some methods have w or A, which is caused by different APIs due to coding. W is encoded in Unicode and A is encoded in Ascii. In fact, there is no big difference in the process of using
WNDCLASS wc; wc.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);// Set background // Register window class RegisterClass(&wc);
3, Create window
The function of creating a window is defined as follows. The names of these methods are very similar. In fact, they are basically used all the time
The difference between W and A is just the difference between sub ah and code
#define CreateWindowA(lpClassName, lpWindowName, dwStyle, x, y,\ nWidth, nHeight, hWndParent, hMenu, hInstance, lpParam)\ CreateWindowExA(0L, lpClassName, lpWindowName, dwStyle, x, y,\ nWidth, nHeight, hWndParent, hMenu, hInstance, lpParam) #define CreateWindowW(lpClassName, lpWindowName, dwStyle, x, y,\ nWidth, nHeight, hWndParent, hMenu, hInstance, lpParam)\ CreateWindowExW(0L, lpClassName, lpWindowName, dwStyle, x, y,\ nWidth, nHeight, hWndParent, hMenu, hInstance, lpParam) #ifdef UNICODE #define CreateWindow CreateWindowW #else #define CreateWindow CreateWindowA #endif // !UNICODE
Click create window to jump to the past and find the complete definition
HWND CreateWindowW( [in, optional] lpClassName, // Window class name (with p for pointer), string char* [in, optional] lpWindowName,// Name of the window (with p for pointer), string char* [in] dwStyle, // WS_OVERLAPPEDWINDOW style [in] x, // Display the coordinates of the window CW_USEDEFAULT [in] y, // (x,y) is the point in the upper left corner of the window [in] nWidth, // Window width [in] nHeight, // Window height [in, optional] hWndParent, // Parent window handle, NULL [in, optional] hMenu, // Window menu handle, NULL [in, optional] hInstance, // Instance handle hinstance (the one passed in from WinMain) [in, optional] lpParam // Mouse added value, left and right keys );
4, Display and update windows
5, Loop get message
First, you need to understand the structure and content of the message. The message definition is as follows
Message structure
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_SYSTEM | WINAPI_PARTITION_GAMES)
/*
* Message structure
*/
typedef struct tagMSG {
HWND hwnd;
UINT message;
WPARAM wParam;
LPARAM lParam;
DWORD time;
POINT pt;
#ifdef _MAC
DWORD lPrivate;
#endif
} MSG, *PMSG, NEAR *NPMSG, FAR *LPMSG;
#endif /* WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_SYSTEM | WINAPI_PARTITION_GAMES) */
Function to get message
WINUSERAPI
BOOL
WINAPI
GetMessageA(
_Out_ LPMSG lpMsg,
_In_opt_ HWND hWnd,
_In_ UINT wMsgFilterMin,
_In_ UINT wMsgFilterMax);
WINUSERAPI
BOOL
WINAPI
GetMessageW(
_Out_ LPMSG lpMsg, // Returned message
_In_opt_ HWND hWnd, // Which window message is captured? If it is NULL, all window messages are captured, and min and max are 0
_In_ UINT wMsgFilterMin,// To capture all messages, set min and max to 0
_In_ UINT wMsgFilterMax);
#ifdef UNICODE
#define GetMessage GetMessageW
#else
#define GetMessage GetMessageA
#endif // !UNICODE
Complete through MFC to create a window and pop up a message
#include <afx.h>
#include <Windows.h>
// Message processing function
LRESULT CALLBACK Wndproc(
HWND hwnd, // The window handle to which the message belongs
UINT uMsg, // Specific message name WM_XXXX message name
WPARAM wparam,// Keyboard additional message
LPARAM lparam // Mouse attached message
) {
switch (uMsg) {
//Clicking the button to close the window will send a WM message_ Destroy message
case WM_CLOSE:
DestroyWindow(hwnd);
break;
//Process destroy message
case WM_DESTROY:
PostQuitMessage(0);//Discard all subsequent messages (meaning end window)
break;
//Left mouse button pops up
case WM_LBUTTONUP:
//int x = LOWORD(lparam);
//int y = HIWORD(lparam);
//A message dialog box pops up
MessageBox(hwnd, TEXT("Pop up message"), TEXT("Title of pop-up box"),MB_OK);
break;
}
// Default message handling
return DefWindowProc(hwnd,uMsg,wparam,lparam);
}
extern "C" int WINAPI _tWinMain(HINSTANCE hInstance, HINSTANCE /*hPrevInstance*/,
LPTSTR /*lpCmdLine*/, int nShowCmd) {
//1. Define window
WNDCLASS wc;
wc.lpszClassName = TEXT("WINDEMO");
wc.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
wc.hCursor = LoadCursor(NULL, IDC_HAND);
wc.hIcon = LoadIcon(NULL, IDI_ERROR);
wc.hInstance = hInstance;
wc.style = 0;
wc.lpszMenuName = NULL;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.lpfnWndProc = Wndproc;
//2. Registration window
RegisterClass(&wc);
// Create a window with width and height of 300, and the window title is demo
HWND hwnd = CreateWindowW(wc.lpszClassName, TEXT("demo"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT,
300, 300, NULL, NULL, hInstance, NULL);
//3. Display and update window
ShowWindow(hwnd, SW_SHOWNORMAL);
UpdateWindow(hwnd);
//4. Loop get message
MSG msg;
while (true) {
if (GetMessage(&msg, NULL, 0, 0) == FALSE) {
break;
}
// Translate messages
TranslateMessage(&msg);
// Distribute messages
DispatchMessage(&msg);
}
return 0;
}