Processing the Message:-
Every
Message that window procedure receives is identified by a number, which message
parameter to the window procedure. WndProc chooses to process only those
messages.
WM_CREATE;
WM_PAINT;
WM_DESTROY;
These three
processes drown by WndProc. It is important to call DefWindowProc for default
processing.
Where to type this code:
·
Open VC++
·
Create new win32 application
project
·
Select a simple win32 application
·
File view-> Source view->
open cpp file and code it.
//Complete
Code for Creating a window
//It
will display a string on the window “www.bcastuff.blogspot.com”
/*
This
application is created in win32 type
do not delete any previously added header
files.
*/
#include <windows.h>//Header File
#include "stdafx.h"
LRESULT CALLBACK WndProc (HWND, UINT,
WPARAM, LPARAM) ;
//this is Windows Procedure.
//defination of Main.
int WINAPI WinMain (HINSTANCE hInstance,
HINSTANCE hPrevInstance,
PSTR szCmdLine, int
iCmdShow)
{
static TCHAR szAppName[] = TEXT ("HelloWin") ;
HWND hwnd ;
MSG msg ;
WNDCLASS wndclass ;
wndclass.style =
CS_HREDRAW | CS_VREDRAW ;
wndclass.lpfnWndProc = WndProc ;
wndclass.cbClsExtra = 0 ;
wndclass.cbWndExtra = 0 ;
wndclass.hInstance = hInstance
;
wndclass.hIcon = LoadIcon
(NULL, IDI_APPLICATION) ;
wndclass.hCursor =
LoadCursor (NULL, IDC_ARROW) ;
wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
wndclass.lpszMenuName = NULL ;
wndclass.lpszClassName = szAppName ;
//Rwgister the class
RegisterClass (&wndclass);
//Windows Create Function
hwnd = CreateWindow (szAppName, // window class name
TEXT ("The Hello
Program"), // window caption
WS_OVERLAPPEDWINDOW, // window style
CW_USEDEFAULT, // initial x position
CW_USEDEFAULT, // initial y position
CW_USEDEFAULT, // initial x size
CW_USEDEFAULT, // initial y size
NULL, // parent window handle
NULL, // window menu handle
hInstance, // program instance handle
NULL) ; // creation parameters
//Show windows function
ShowWindow (hwnd, iCmdShow) ;
UpdateWindow (hwnd) ;
//Message Loop
while (GetMessage (&msg, NULL, 0, 0))
{
TranslateMessage (&msg) ;
DispatchMessage (&msg) ;
}
return msg.wParam ;
}
//Windows Procedure.
LRESULT CALLBACK WndProc (HWND hwnd, UINT
message, WPARAM wParam, LPARAM lParam)
{
HDC hdc ;
PAINTSTRUCT ps ;
RECT rect ;
switch (message)
{
case WM_CREATE:
return 0 ;
case WM_PAINT:
hdc = BeginPaint (hwnd, &ps) ;
GetClientRect (hwnd, &rect) ;
//This line display the message
TextOut(hdc,500,400 ,TEXT ("www.bcastuff.blogspot.com"), 27) ;
EndPaint (hwnd, &ps) ;
return 0 ;
case WM_DESTROY:
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}
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