C / C++ / MFC

22-Jul-09 21:19

Hello all,
i am using ReadFile function to Read a Sector from different type of storage devices like Pen Drive, Hard Disk, Memory Card iPod.

with all devices excluding iPod it is working fine means it return 1.
when i am trying to Read iPod it fails means it return 0;

i am using apples 120 GB iPOD, and when i try to get error Code by using
DWORD dw = GetLastError();
it is 87

/////used by window9x

long drive_num;
int sector, disk_read;
int drive_no;
char drv,szflp_drv[20];

strcpy(szflp_drv , "\\\\.\\a:");

char phydisk[20];
strcpy(phydisk,p);// p is a string like "\\\\.\\PhysicalDrive0",+"Drive No"
//Ex. if Drive No.3 then "\\\\.\\PhysicalDrive3",
drv = p[17];

/////used by windowsnt
HANDLE hCD;
DWORD dwNotUsed;

drive_no = atoi(&drv);
///////////////////////////////////
//////Check which os is installed

hCD = CreateFile (phydisk, GENERIC_READ ,
FILE_SHARE_READ|FILE_SHARE_WRITE,
NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,
NULL);

if (hCD != INVALID_HANDLE_VALUE)
{
DWORD dwSize = total_sector * 512;
__int64 y=512*start_sector;
__int64 ss= myFileSeek(hCD,y,FILE_BEGIN);

int aa;
aa = ReadFile (hCD, buffer, dwSize, &dwNotUsed, NULL);

DWORD dw = GetLastError();
}

Michael Schubert22-Jul-09 21:47

Michael Schubert

22-Jul-09 21:47

Shiv Murti Pal wrote:
DWORD dw = GetLastError();
it is 87

First clue:
87 = ERROR_INVALID_PARAMETER

Shiv Murti Pal22-Jul-09 23:37

22-Jul-09 23:37

where is error plese suggest me

Michael Schubert22-Jul-09 23:53

Michael Schubert

22-Jul-09 23:53

It means that one of the parameters (probably for ReadFile) is invalid. Use the debugger and check the values.

Shiv Murti Pal23-Jul-09 2:27

23-Jul-09 2:27

Before executing the value of ReadFile Parameters are
int aa;
aa = ReadFile (hCD, buffer, dwSize, &dwNotUsed, NULL);

hCD = 0x00000798
buffer = 0x0012f1bc
dwSize = 512
dwNotUsed = 3435973836
NULL

After executing the value of ReadFile Parameters are

dwNotUsed = 0

All other are Same

Note:- in case of all other devices where the ReadFile return success (1)

dwNotUsed = 512

Now Sir suggest me what i should do

krmed23-Jul-09 2:51

krmed

23-Jul-09 2:51

Have you seen the Return Value section of MSDN?

If the function succeeds, the return value is nonzero.

If the function fails, the return value is 0 (zero). To get extended error information, call GetLastError.

If the return value is nonzero and the number of bytes read is 0 (zero),
the file pointer is beyond the current end of the file at the time of
the read operation. However, if the file is opened with FILE_FLAG_OVERLAPPED
and lpOverlapped is not NULL, the return value is 0 (zero) and GetLastError
returns ERROR_HANDLE_EOF when the file pointer goes beyond the current end
of file.

What is the value of aa when the function returns? Try calling GetLastError() to get more information.

Karl - WK5M
PP-ASEL-IA (N43CS)
PGP Key: 0xDB02E193
PGP Key Fingerprint: 8F06 5A2E 2735 892B 821C 871A 0411 94EA DB02 E193

Shiv Murti Pal23-Jul-09 18:56

23-Jul-09 18:56

the value of aa is 0 i have already explained

Shiv Murti Pal24-Jul-09 1:25

How to generate Keyboard events ?

24-Jul-09 1:25

hello sir/Madam (Michael Schubert)

Sir please guide me sir, i think u ware only one step away from solution, in your last responce please help sir

Member 383463022-Jul-09 21:14

Member 3834630

22-Jul-09 21:14

Hi,

How to generate Keyboard events.
I want to generate Alt+Tab Event in middle of my application.
How to generate Alt+Tab event in a dialog based application.

Thanks in advance.

With best wishes.

Emilio Garavaglia22-Jul-09 21:52

Emilio Garavaglia

22-Jul-09 21:52

Just call SendMessage to the intended window, giving the arguments the value you want to expect from that event.

2 bugs found.
> recompile ...
65534 bugs found.
D'Oh! | :doh:

«_Superman_»22-Jul-09 22:18

«_Superman_»

22-Jul-09 22:18

SendInput[^]

«_Superman_»
I love work. It gives me something to do between weekends.

Adam Roderick J22-Jul-09 22:45

Adam Roderick J

22-Jul-09 22:45

keybd_event

http://msdn.microsoft.com/en-us/library/ms646304(VS.85).aspx[^]

Kushagra Tiwari23-Jul-09 0:16

Kushagra Tiwari

23-Jul-09 0:16

You can use either SendMessage() or PostMessage() depending on you requirement.

There are a few subtle differences in the ways you can send messages in Windows, but the basic difference between PostMessage and SendMessage is that SendMessage sends a message to another window immediately by calling that window's procedure and waiting for it to return, whereas PostMessage queues the message in an MSG structure and returns immediately"without waiting. MSG is short for message, not monosodium glutamate.
With SendMessage, the receiving app processes the message immediately, rather than at some later time, by fetching it from its queue. For example, suppose you write:

pWnd->SendMessage(WM_KEYDOWN);
pWnd->PostMessage(WM_KEYDOWN);

There are different indicators for which key was pressed .Kindly, go through that list and do the apporopiate Smile | :)

Kushagra

I hate coding but I love to develop Smile | :)

Member 383463023-Jul-09 0:43

Member 3834630

23-Jul-09 0:43

Thank you.

Using keybd_event how to generate Alt+Tab.

I tried both of the below options but failed.

1 ------------
keybd_event( VK_MENU ,0x45,KEYEVENTF_EXTENDEDKEY | 0, 0 );
keybd_event( VK_TAB ,0x45,KEYEVENTF_EXTENDEDKEY | 0, 0 );

keybd_event( VK_TAB ,0x45,KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,0);
keybd_event( VK_MENU ,0x45,KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,0);

2 ------------
keybd_event( VK_MENU | VK_TAB ,0x45,KEYEVENTF_EXTENDEDKEY | 0, 0 );
keybd_event( VK_MENU | VK_TAB ,0x45,KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,0);

Please let me know how to use for Alt+Tab combination to change the window.