Structure of Window Program

• WinMain () function

int WINAPI WinMain (    hinstance hinstance,    hinstance hprevinstance,    LPSTR lpcmdline,    int  ncmdshow    ) {    return0;}

The hinstance:hinstance type, which points to the handle of an instance, is a running program.

lpCmdLine: A pointer to a string containing the command-line character of the launcher.

nCmdShow: Determines the appearance of the created window.

• Window procedure Functions

messages that a application receives from the operating system. " This function handles many messages that the application receives from the operating system.  ok button when the user Clicks the button, the operating system sends the application a message, the button was clicked. " > wndproc  is responsible for responding to the event.  

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);

• Specifying the program window

Wndclssex: A special struct type that contains the data used to specify the window.

struct tagwndclassex {  UINT      cbsize;       The size, in bytes, of this structure.     UINT      style;  WNDPROC   Lpfnwndproc;   int        Cbclsextra;   int        Cbwndextra;  HINSTANCE hinstance;  Hicon     Hicon;  Hcursor   hcursor;  Hbrush    Hbrbackground;  LPCTSTR   Lpszmenuname;  LPCTSTR   lpszClassName;  Hicon     *pwndclassex;

Constructs a Wndclassex type object and fills in the value of an object member

static LPCTSTR Szappname = L "APP";

Wndclassex Windowclass; Windowclass.cbsize=sizeof(Wndclassex); Windowclass.style= Cs_hredraw | Cs_vredraw;//to change the width or height of a window, redraw the windowWindowclass.lpfnwndproc =WndProc;//stores a pointer to a function that handles messages in a programWindowclass.cbclsextra =0;//Extra space for special useWindowclass.cbwndextra =0;//Extra space for special useWindowclass.hinstance = hinstance;//Handle to accommodate the current application instanceWindowclass.hicon = LoadIcon (hinstance, Makeintresource (idi_application));//defines the icon for the application when minimizedWindowclass.hcursor = LoadCursor (NULL, Idc_arrow);//defines the cursor used by the windowWindowclass.hbrbackground = (hbrush) (Color_window +1);//defines the background color of the window's workspaceWindowclass.lpszmenuname = NULL;//name of the resource that defines the Window menuWindowclass.lpszclassname = Szappname;//stores the name provided to identify that particular window class, typically using the name of the application to assign a value to the memberWINDOWCLASS.HICONSM = LoadIcon (Windowclass.hinstance, Makeintresource (idi_application));//identifies a small icon that is associated with the window class

• To create a program window

Registered wound type

RegisterClassEx (&windowclass);

Creating a window, using the function CreateWindow (), and other real differences passed to the CreateWindow () function adds some additional attributes that return a handle to the window that was created.

HWND WINAPI CreateWindow (  _in_opt_  lpctstr lpclassname,  _in_opt_  lpctstr lpwindowname,  _in _      DWORD dwstyle,  _in_      int  x,  _in_      int  y,  _in_       int nwidth,  _in_      int  nheight,  _in_opt_  HWND hwndparent,  _in_opt_  HMENU HMENU,  _in_opt_  hinstance hinstance,  _in_opt_  lpvoid lpparam);

HWND hwnd; HWnd=CreateWindow (Szappname,//The class name used to identify the wndclassex struct previously passed in the RegisterClassEx () function callSzTitle,//define the text that appears on the title barWs_overlappedwindow,//defines the style that the window should have after it is createdCw_usedefault, Cw_usedefault, -, -,//define the position and size of the window on the screenNull//handle to parent windowNull//No menus requiredHINSTANCE,//specifies a handle to the current program instance that is passed to the program by WindowsNull//Multi-Document interface);

Display window

ShowWindow (HWnd, ncmdshow);

Redraw window

UpdateWindow (HWND);

Structure of Window Program