Windows Simple Program-Win32

1. SIMPLE WINDOW PROGRAM

             PROGRAM:

#include <windows.h>

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

int WINAPI WinMain ( HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow )

{

 static  TCHAR szAppName[]=TEXT ("HELLO");

HWND hwnd;

MSG msg;

// DECLARING AND INTIAZING THE WINDOW CLASS

WNDCLASS wc;                                                       // Window class declaration

wc.style = CS_HREDRAW| CS_VREDRAW;        // Window style

wc. lpfnWndProc = WndProc;                                   // Window Procedure

wc.cbClsExtra = 0;                                                     // Extra Parameters

wc.cbWndExtra = 0;                                                   // Extra Parameters

wc.hInstance = hInstance;                                          // Instance handle

wc.hIcon = LoadIcon (NULL, IDI_APPLICATION); // Icon

wc.hCursor = LoadCursor (NULL, IDC_ARROW);            // Window Cursor

wc.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH);

                                                                                    // Set Background Color

wc.lpszMenuName = NULL;                                     // Menu Handle

wc.lpszClassName = szAppName;                             // Class Name

// REGISTERING THE WINDOW CLASS

if (!RegisterClass (&wc))

{

            MessageBox(NULL, TEXT("This program requires WindowsNT!"), szAppName, MB_ICONERROR);

            return 0;

}

// CREATING THE WINDOW

hwnd = CreateWindow ( szAppName,   // window class name

TEXT("The Hello Program"), // window caption 

WS_OVERLAPPEDWINDOW,      // window style

CW_USEDEFAULT,          // initial x position

CW_USEDEFAULT,  // initial x position

CW_USEDEFAULT,         // initial x position

CW_USEDEFAULT,              // initial x position

NULL,                         // parent window  handle

NULL,                               // window menu handle

hInstance,                          //program instance handle

NULL);                           // creation parameters

// DISPLAYING THE WINDOW

            ShowWindow (hwnd, iCmdShow);              

            UpdateWindow (hwnd);

// PROCESSING THE MESSAGE LOOP

            while (GetMessage(&msg,NULL,0,0) // extracts message from Message Queue

            {

                                                TranslateMessage (&msg);  // dispatches the message received

                        DispatchMessage (&msg);

            }

            return msg.wParam;

}

// WINDOW PROCEDURE FUNCTION

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam)

{

            HDC hdc;

            PAINTSTRUCT ps;

            RECT rect;

            switch (message)

            {

            case WM_PAINT:    // Used to draw on client area using objects

                        hdc = BeginPaint (hwnd, &ps); // Gets Device Context

                        GetClientRect (hwnd, &rect);   // To get Client area size

                        DrawText (hdc, TEXT ("HELLO WINDOWS 98"),-1, &rect, DT_SINGLELINE | DT_CENTER | DT_VCENTER);

                        EndPaint(hwnd,&ps);    // Releases Device Context

                        return 0;

            case WM_DESTROY:     // Used to close the window

                        PostQuitMessage(0);  // used to terminate while loop in WinMain()

                        return 0;

            }

            return DefWindowProc (hwnd, message, wparam, lparam);

}

Sample Output: