|
...............By
Adarsh Hoizal |
|
To
Create a file on the local drive. Assume the path to
be C:\ and create a text file called
file1.txt. Use Windows API function CreateFile or
OpenFile, i.e Do not use C function fopen. |
#include<windows.h>
#include<stdio.h>
#define FILEPATH "c:\\file1.txt"
/* This is the path */
main()
{
HANDLE filehandle;
DWORD h;
filehandle=CreateFile( FILEPATH,GENERIC_READ|GENERIC_WRITE,0,NULL,CREATE_ALWAYS,0,NULL);
/*This creates the file, if file
already exists, it overwrites it. */
if(INVALID_HANDLE_VALUE==filehandle)
{
printf("File could not be created as
function returned an invalid handle \n\n ");
return 0;
}
printf("File
successfully created");
CloseHandle(filehandle);
/* Close the open file handle */
printf("\n\n");
return 0;
}
| To
read the contents of a text file and count the number
of lines and words in it. Assume the path to be C:\file1.txt.
Use Windows API function ReadFile, i.e Do not use C
function fread. |
#include<windows.h>
#include<stdio.h>
#define MAX 100
#define FILEPATH "c:\\file1.txt"
/* This is the File Path */
main()
{
HANDLE filehandle;
DWORD h;
int readerror=0;
/* readerror returns the status of read operation, it could
also be a boolean type since it returns only two values*/
int linecount=0,wordcount=0;
bool wordstarted=false;
char c;
DWORD chars;
filehandle=CreateFile( FILEPATH,GENERIC_READ|GENERIC_WRITE,0,NULL,OPEN_EXISTING,0,NULL);
/* The file would open only if it
exists. In case the file does not exist at the specified path,
the above function fails */
if(INVALID_HANDLE_VALUE==filehandle)
{
printf("File could not be opened as function
returned an invalid handle ");
return 0;
}
/*
The below code executes only if CreateFile returns a valid
file handle */
chars=0;
while(1)
{
readerror=ReadFile(filehandle,&c,1, &h,NULL);
/* ReadFile returns
a bool type TRUE or FALSE into readerror. If readerror=0
or FALSE, then file read operation was not successful. In case
it returns a 1 or TRUE, read operation was successful. The
number of bytes read from the file is returned as a DWORD and
is stored into h. Hence to check whether the read
operation was successful or not, we have to check the return
values of readerror and h. */
if (readerror==0 || h<=0 )
/* An alternate method of checking this
would be to check if (readerror && h)==0
*/
{
if(wordstarted) wordcount++;
if(chars>0 && linecount==0) linecount++;
break;
}
chars++;
if( c==' ')
/* Check for blank spaces
*/
{
if(wordstarted)
{
wordcount++;
wordstarted=FALSE;
}
}
else
{
if(c!='\n')
/* Check for newline escape
sequence */
{
if(c!='\r')
/* Check for carriage
returns */
{
if(!wordstarted)
{
wordstarted=TRUE;
}
}
}
else
{
if(wordstarted) wordcount++;
wordstarted=FALSE;
linecount++;
}
}
}
printf("\n\n");
printf("Number of Words = %d",wordcount);
printf("\n\n");
printf("Number of Lines = %d",linecount);
CloseHandle(filehandle);
/* Close the open file handle */
printf("\n\n");
return 0;
}
| To
add the contents of two text files and store it in a
third text file. Use Windows API functions. Assume the
two files to be file1.txt and file2.txt stored in
C:\ Create a third file called
file3.txt and store the result in it. |
#include<windows.h>
#include<stdio.h>
#define MAX 4*1024 /*
Max size of Array = 4k Arrays give a very fast performance but
is inefficient */
#define FILEPATH1 "d:\\file1.txt"
/* File 1 to read from */
#define FILEPATH2 "d:\\file2.txt"
/* File 2 to read
from */
#define FILEPATH3 "d:\\file3.txt"
/* File 3 to write into
File 3 = File 1 + File 2 */
int main()
{
/* Define Arrays */
char Arr1[MAX]="";
char Arr2[MAX]="";
char Arr3[MAX]="";
/* Define File Handles */
HANDLE filehandle1;
HANDLE filehandle2;
HANDLE filehandle3;
/* Define number of bytes
read/written from/to files */
DWORD h1;
DWORD h2;
DWORD h3;
int readerror;
int writeerror;
filehandle1 = CreateFile( FILEPATH1,
GENERIC_READ | GENERIC_WRITE,
0,
NULL,
OPEN_EXISTING,
0,
NULL );
if(INVALID_HANDLE_VALUE==filehandle1)
{
MessageBox(0,"File 1 returned Invalid Handle", "Error",0);
printf("Error Number = %d",GetLastError());
return 0;
}
readerror=ReadFile(filehandle1, Arr1,sizeof(Arr1),&h1,NULL );
if((readerror && h1)==0)
{
MessageBox(0,"Error Reading File 1", "Read Error",0);
printf("Error Number =%d",GetLastError());
CloseHandle(filehandle1);
return 0;
}
Arr1[h1]='\0';
filehandle2 = CreateFile( FILEPATH2,
GENERIC_READ | GENERIC_WRITE,
0,
NULL,
OPEN_EXISTING,
0,
NULL );
if(INVALID_HANDLE_VALUE==filehandle2)
{
MessageBox(0,"File 2 returned Invalid Handle",
"Error",0);
printf("Error Number = %d",GetLastError());
return 0;
}
readerror=ReadFile(filehandle2, Arr2,sizeof(Arr2),&h2,NULL );
if((readerror && h2)==0)
{
MessageBox(0,"Error Reading File 2", "Read Error",0);
printf("Error Number =%d",GetLastError());
CloseHandle(filehandle2);
CloseHandle(filehandle1);
return 0;
}
Arr2[h2]='\0';
/*
Add contents of Array 1 and Array 2 to Array 3 */
strcpy(Arr3,Arr1);
strcat(Arr3,Arr2);
filehandle3= CreateFile( FILEPATH3,
GENERIC_READ | GENERIC_WRITE,
0,
NULL,
CREATE_ALWAYS,
0,
NULL );
if( INVALID_HANDLE_VALUE ==filehandle3)
{
MessageBox(NULL,"Invalid File Handle 3","Error",0);
printf("Error Number =%d",GetLastError());
CloseHandle(filehandle2);
CloseHandle(filehandle1);
return 0;
}
else
{
writeerror=WriteFile(filehandle3,Arr3,strlen(Arr3),&h3,NULL);
if(!writeerror)
{
MessageBox(NULL,"Cannot write to File","Write Error",0);
printf("Error Number =%d",GetLastError());
CloseHandle(filehandle3);
CloseHandle(filehandle2);
CloseHandle(filehandle1);
return 0;
}
}
printf("Program successfully completed.");
printf("\n\n");
return 0;
}
|
Win32
Non Console based Applications |
|
...............By
Adarsh Hoizal |
|
To
Create a simple window. |
#include<windows.h>
LRESULT CALLBACK
myfunc(HWND,UINT,WPARAM,LPARAM);
/* This will handle the message calls */
int WINAPI WinMain(HINSTANCE h, HINSTANCE
p,LPSTR l, int n)
{
WNDCLASS w ; /*
Its a structure whose elements we need to fill
in */
HWND handle ;
MSG m ;
w.cbClsExtra =0 ;
w.cbWndExtra =0 ;
w.hbrBackground =(HBRUSH)
GetStockObject(WHITE_BRUSH) ;
w.hCursor =0 ;
w.hIcon=0 ;
w.hInstance =h ;
w.lpfnWndProc =myfunc ;
w.lpszClassName ="MyClass"
;
w.lpszMenuName =NULL ;
w.style =0 ;
/*
First we need to register the class with the
Windows */
if(!RegisterClass(&w)) return
0 ;
/*
Now that the class has been registered we can
create the window */
handle=CreateWindow("MyClass",
/*
Class Name */
"Adarsh's Window", /*
Title Text */
WS_OVERLAPPEDWINDOW, /*
Style */
50,
/*
X Co-ordinate */
50,
/*
Y Co-ordinate */
300,
/*
Width */
300,
/* Height */
0,
/* Parent Window */
0,
/* Child Identifier */
h,
/*
Application Instance */
0)
;
/*
Window creation data
*/
if (!handle) return 0; /*
In case handle is not created terminate
program */
ShowWindow(handle,n);
UpdateWindow(handle);
/*
Now the window is created and we just need to
get messages from the windows operating system
about various events encountered by it.
Whatever message we feel is appropriate to
take some action would be dealt with
accordingly and remaining would be left to the
operating system to take care of */
while(GetMessage(&m,0,0,0))
{
TranslateMessage(&m);
DispatchMessage(&m);
}
return m.wParam ;
}
LRESULT CALLBACK myfunc(HWND hw,UINT
msg,WPARAM wP,LPARAM lP)
{
switch(msg)
{
/* Trap
the event of closing the window. When found,
terminate the program and return 0 to compiler
indicating successful program execution */
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
/*
In any other event let windows handle the
message */
return DefWindowProc(hw,msg,wP,lP);
}
return 0;
}
|
| To
make your own SCREEN SAVER with your own
custom settings. Compile the below program to
generate an icon. Select this icon from the
Screen Saver dialog box. Please note that you
also need to make/copy an icon which would be
stored in the resource file. |
#include<windows.h>
#include<scrnsave.h>
BOOL WINAPI
ScreenSaverConfigureDialog(HWND,UINT,WPARAM,LPARAM);
/*
These functions are not used */
BOOL WINAPI RegisterDialogClasses(HANDLE);
/*
but
could be used
to enhance screen saver features */
char
str[80]="Welcome to Adarsh Hoizal's
Homepage";
/*
The text you want to display */
int delay=200;
LRESULT CALLBACK ScreenSaverProc(HWND hwnd , UINT message, WPARAM wparam ,LPARAM lparam)
{
static HDC hdc;
static unsigned int timer;
static RECT scrdim;
static SIZE size;
static int X=0, Y=0;
static HBRUSH hBlkBrush;
static TEXTMETRIC tm;
switch(message)
{
case WM_CREATE :
timer=SetTimer(hwnd,1,delay,NULL);
hBlkBrush=(HBRUSH) GetStockObject(BLACK_BRUSH);
break;
case WM_ERASEBKGND:
hdc=GetDC(hwnd);
GetClientRect(hwnd,&scrdim);
SelectObject(hdc,hBlkBrush);
PatBlt(hdc,0,0,scrdim.right,scrdim.bottom,PATCOPY);
GetTextMetrics(hdc,&tm);
GetTextExtentPoint32(hdc,str,strlen(str),&size);
ReleaseDC(hwnd,hdc);
break;
case WM_TIMER:
hdc=GetDC(hwnd);
SelectObject(hdc,hBlkBrush);
PatBlt(hdc,X,Y,X+size.cx,Y+size.cy,PATCOPY);
X+=10;Y+=10;
if(X>scrdim.right) X=0;
if(Y>scrdim.bottom)Y=0;
SetBkColor(hdc,RGB(0,0,0));
SetTextColor(hdc,RGB(0,255,255));
TextOut(hdc,X,Y,str,strlen(str));
ReleaseDC(hwnd,hdc);
break;
case WM_DESTROY:
KillTimer(hwnd,timer);
break;
default:
return DefScreenSaverProc(hwnd,message,wparam,lparam);
}
return 0;
}
BOOL WINAPI ScreenSaverConfigureDialog(HWND hdwnd,UINT message,WPARAM wparam,LPARAM lparam)
{
return 0;
}
BOOL WINAPI RegisterDialogClasses(HANDLE hInst)
{
return 1;
}
|
Write
a program to create a Pop up timer. |
#include <windows.h>
#include "resource.h" /*
See the Resource file below *?
WNDCLASS w;
MSG m;
HWND hMainWnd;
HMENU hMenu, hPop;
int x,y;
POINT p;
int pos;
int toggle = 0;
int flag;
LRESULT CALLBACK TimerProc(HWND hWnd,UINT msg,WPARAM wParam,LPARAM lParam)
{
switch(LOWORD(wParam))
{
case 1:
MessageBox(hWnd,"Timer 1","Alert",0);
break;
case 2:
MessageBox(hWnd,"Timer 2","Alert",0);
break;
}
return 0;
}
LRESULT CALLBACK wp(HWND hWnd,UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_DESTROY:
PostQuitMessage(0);
break;
case WM_CREATE:
break;
case
WM_RBUTTONDOWN:
x = LOWORD(lParam);
y = HIWORD(lParam);
p.x = x;
p.y = y;
ClientToScreen(hWnd,&p);
TrackPopupMenu(hPop,TPM_LEFTALIGN,p.x,p.y ,0,hWnd,0);
break;
case WM_INITMENUPOPUP:
hMenu = (HMENU) wParam;
pos = LOWORD(lParam);
toggle = (toggle == 0)?1:0;
flag = (toggle==1)?MF_GRAYED:MF_ENABLED;
EnableMenuItem(hMenu,IDM_F_OPEN,flag|MF_BYCOMMAND);
break;
case WM_COMMAND:
switch(LOWORD(wParam))
{
case 1:
MessageBox(hWnd,"Item 1","Alert",0);
break;
case 2:
MessageBox(hWnd,"Item 2","Alert",0);
break;
case IDM_F_OPEN:
MessageBox(hWnd,"File Opened","Alert",0);
break;
case IDM_F_CLOSE:
MessageBox(hWnd,"File Closed","Alert",0);
break;
case IDM_F_EXIT:
MessageBox(hWnd,"Bye","Alert",0);
DestroyWindow(hWnd);
break;
}
break;
default:
return DefWindowProc(hWnd,msg,wParam,lParam);
}
return 0l;
}
int WINAPI WinMain(HINSTANCE hInst,HINSTANCE
hPrev, LPSTR lpszCommand, int nCmdShow)
{
w.cbClsExtra = 0;
w.cbWndExtra = 0;
w.hbrBackground = GetStockObject(WHITE_BRUSH);
w.hCursor = LoadCursor(0,IDC_ARROW);
w.hIcon = LoadIcon(0,IDI_APPLICATION);
w.hInstance = hInst;
w.lpfnWndProc = wp;
w.lpszClassName = "TimeTested";
w.lpszMenuName = 0;
w.style = CS_HREDRAW| CS_VREDRAW;
if (!RegisterClass(&w)) return 0;
hMenu =
LoadMenu(hInst,MAKEINTRESOURCE(IDM_MAIN));
/*
This will provide handle to the resource
object */
hPop = CreatePopupMenu();
if (!hPop) return 0;
AppendMenu(hPop,MF_STRING,1,"Item1");
AppendMenu(hPop,MF_STRING,2,"Item2");
hMainWnd = CreateWindow("TimeTested","Time",WS_OVERLAPPEDWINDOW,10,10,200,200,0,hMenu,hInst,0);
if(!hMainWnd) return 0;
ShowWindow(hMainWnd,nCmdShow);
while(GetMessage(&m,0,0,0))
{
TranslateMessage(&m);
DispatchMessage(&m);
}
return m.wParam;
}
Resource.h
contains the following
//{{NO_DEPENDENCIES}}
// Microsoft Developer Studio generated include file.
// Used by MainScript.rc
#define IDM_MAIN 101
#define IDM_POPUP 102
#define IDM_F_OPEN 40001
#define IDM_F_CLOSE 40002
#define IDM_F_EXIT 40003
#define IDM_E_CUT 40004
#define ID_CONTEXT 40005
#define ID_ITEM2 40006
#define ID_ITEM3 40007
// Next default values for new objects
#ifdef APSTUDIO_INVOKED
#ifndef APSTUDIO_READONLY_SYMBOLS
#define _APS_NEXT_RESOURCE_VALUE 103
#define _APS_NEXT_COMMAND_VALUE 40008
#define _APS_NEXT_CONTROL_VALUE 1000
#define _APS_NEXT_SYMED_VALUE 101
#endif
#endif
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