Visual Basic

Re: Accessed by another process

15-Nov-07 10:56

FYI:

if you want write or delete access (anything other than read access) to a file
that just got created (by yourself or someone else, does not matter),
chances are you will find the file is being accessed by some other process,
and your access is not granted.

The other process very likely is some server code that is there to assist you
somehow. Candidates are:
- anti-virus software (Norton, McAfee, whatever)
- indexing software (Google Desktop, MS Office, whatever)
The common thing is these packages are looking all the time for new files, so
they can inspect them.

Microsoft is aware of the consequences; Windows Explorer will try rename and
delete attempts up to five times (with one-second interval), and only reports
failure if the action continues to fail for that time.

The solution:
1. either use a different file name
2. or remove all background reader candidates (bad idea)
3. or implement the retry loop as Explorer has it (use a Windows.Forms.Timer
for this)

BTW: if all you need is Read, make sure to allow others to read as well, i.e.
use File.Open(path, FileMode.Open, FileAccess.Read, FileShare.Read)

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

this months tips:
- use PRE tags to preserve formatting when showing multi-line code snippets
- before you ask a question here, search CodeProject, then Google

KreativeKai16-Nov-07 3:25

KreativeKai

16-Nov-07 3:25

Thanks to both of you for your replies. I had the logic in a try catch, but it was a fairly wide open section of code. I narrowed down the code to several try catch sections and did exactly what Luc suggested as solution #3. I setup logic to retry the delete up to 6 times with a delay of 20 seconds between, and it worked.

The application I was having trouble with, has been in production working flawlessly for two years. It takes report spoolfiles off of our miniframe and translates them into PDF for delivery via e-mail or posting on our intranet. The problem came into light when my boss tried to put a 4000 page financial report which was 35MB in size through the application. It worked and sent a 7MB PDF to him via e-mail, but errored out when it tried to delete the original data / report file.

Thanks for your help! It's working flawlessly again. Smile | :)

Lost in the vast sea of .NET

Preload images / Speed up images

SiXke15-Nov-07 8:04

15-Nov-07 8:04

Hello

Im using a background image on my form, and some pictureboxes that are used as buttons.

I load some other forms from the main form with the same setup(background picture+pictureboxes)

I takes quite a while to load this images.

Is there a way i can preload the images, or speed up the image loading?

Thank you

Luc Pattyn15-Nov-07 8:20

15-Nov-07 8:20

Hi,

if the images are much larger than what you need (hence the PictureBoxes will scale them
down), you could create smaller or even correctly sized images once and store them either
in separate files, or as resources in your exe/dll. This would, for each form, save both
the time to load the larger images, and the time to scale them down.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

this months tips:
- use PRE tags to preserve formatting when showing multi-line code snippets
- before you ask a question here, search CodeProject, then Google

SiXke15-Nov-07 9:26

15-Nov-07 9:26

Already doing that Smile | :)

More ideas?

Luc Pattyn15-Nov-07 9:35

15-Nov-07 9:35

OK, time to get more specific. I'm looking for something (slightly) unusual:

What is your hardware? modern CPU, RAM size, disk speed?

what about your form(s): size, number of PictureBoxes, number of other Controls?

what is the size of the image files on disk? and in pixels? which format?

SiXke wrote:
I takes quite a while to load this images

like how long? 100msec, 1sec, 10sec?

anything special about your code? extra events, extra logging?

network involved? database involved?

as a reference, you could maximize, then minimize, then measure the restore time;
and possibly show the Resize and/or Paint handlers involved.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

this months tips:
- use PRE tags to preserve formatting when showing multi-line code snippets
- before you ask a question here, search CodeProject, then Google

SiXke16-Nov-07 5:49

16-Nov-07 5:49

Luc Pattyn wrote:
What is your hardware? modern CPU, RAM size, disk speed?

4000+ / 2GB RAM / Raptor 10.000rpm

Luc Pattyn wrote:
what about your form(s): size, number of PictureBoxes, number of other Controls?

Form size: 1920*1080 - 4 Picture boxes - No other controls

Luc Pattyn wrote:
what is the size of the image files on disk? and in pixels? which format?

Background image: 1920*1080(97Kb) Pictureboxes: 300*300 (x4)(50-60Kb) all JPEG

Luc Pattyn wrote:
like how long? 100msec, 1sec, 10sec?

Say like 1 sec, for example, when the form opens, i see the background, and a sec later the pictureboxes.

Luc Pattyn wrote:
anything special about your code? extra events, extra logging?

nothing, simple FrmSub.show on the pictureboxes

Luc Pattyn wrote:
network involved? database involved?

no network, access database used in the program, but has nothing to do with the pictures, and is not loaded during form load.

Luc Pattyn wrote:
and possibly show the Resize and/or Paint handlers involved.

where can i find this?

Thnak you for your help man.

Do you think it would help to change from JPEG to GIF? (Pictures have max 10 different colors)

Luc Pattyn16-Nov-07 6:04

16-Nov-07 6:04

Hi,

it all sounds very reasonable.
and 1 sec is not too bad either.

SiXke wrote:
where can i find this?

If you don't know, you don't have them, and they can't be a problem...

Here are a couple of things you could try:
1. a simpler image format for the pictureboxes, such as GIF.
2. embedding the images in the app itself, as resources.
3. set Form.DoubleBuffered true; that will not really solve much but it may change the look and
feel in the way you prefer (I expect it to show the form a bit later but with less activity!).

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

this months tips:
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use PRE tags to preserve formatting when showing multi-line code snippets

SiXke17-Nov-07 6:07

17-Nov-07 6:07

Luc Pattyn wrote:
3. set Form.DoubleBuffered true; that will not really solve much but it may change the look and
feel in the way you prefer (I expect it to show the form a bit later but with less activity!).

Just what i needed.

Thx man

SiXke24-Nov-07 4:34

PHPbb 3 RC 7 password hash [modified]

24-Nov-07 4:34

Hi again

The forms with only pictureboxes work like i want, but i have some forms with lots of labels and textboxes, and they still load slow.

Is there a way to preload a form?

I dont mind waiting on a form to load, i mind that the form is loaded in pieces.

Thank you again

LegionFX15-Nov-07 5:54

LegionFX

15-Nov-07 5:54

hi... someone can help me it this. i once have made a application that users login using my forum login but now i installed phpbb 3 and the password hash is not md5 anymore!!! someone can tell me how can i make the password hash for this ? i think its utf8_bin but not sure. im confused. the passwords in the database have this format -
Ex:

$H$9DL4NAPoOsmVdZpIrOJcH3KfvVoV3h1
this hash translated is - 11293045

how can i make a user autenticate is this...
thanks

this is a sample php class that does the job but dont know how to make this in vb.net

class PasswordHash {
var $itoa64;
var $iteration_count_log2;
var $portable_hashes;
var $random_state;

function PasswordHash($iteration_count_log2, $portable_hashes)
{
$this->itoa64 = './0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';

if ($iteration_count_log2 < 4 || $iteration_count_log2 > 31)
$iteration_count_log2 = 8;
$this->iteration_count_log2 = $iteration_count_log2;

$this->portable_hashes = $portable_hashes;

$this->random_state = microtime() . getmypid();
}

function get_random_bytes($count)
{
$output = '';
if (($fh = @fopen('/dev/urandom', 'rb'))) {
$output = fread($fh, $count);
fclose($fh);
}

if (strlen($output) < $count) {
$output = '';
for ($i = 0; $i < $count; $i += 16) {
$this->random_state =
md5(microtime() . $this->random_state);
$output .=
pack('H*', md5($this->random_state));
}
$output = substr($output, 0, $count);
}

return $output;
}

function encode64($input, $count)
{
$output = '';
$i = 0;
do {
$value = ord($input[$i++]);
$output .= $this->itoa64[$value & 0x3f];
if ($i < $count)
$value |= ord($input[$i]) << 8;
$output .= $this->itoa64[($value >> 6) & 0x3f];
if ($i++ >= $count)
break;
if ($i < $count)
$value |= ord($input[$i]) << 16;
$output .= $this->itoa64[($value >> 12) & 0x3f];
if ($i++ >= $count)
break;
$output .= $this->itoa64[($value >> 18) & 0x3f];
} while ($i < $count);

return $output;
}

function gensalt_private($input)
{
$output = '$P$';
$output .= $this->itoa64[min($this->iteration_count_log2 +
((PHP_VERSION >= '5') ? 5 : 3), 30)];
$output .= $this->encode64($input, 6);

return $output;
}

function crypt_private($password, $setting)
{
$output = '*0';
if (substr($setting, 0, 2) == $output)
$output = '*1';

if (substr($setting, 0, 3) != '$P$')
return $output;

$count_log2 = strpos($this->itoa64, $setting[3]);
if ($count_log2 < 7 || $count_log2 > 30)
return $output;

$count = 1 << $count_log2;

$salt = substr($setting, 4, 8);
if (strlen($salt) != 8)
return $output;

# We're kind of forced to use MD5 here since it's the only
# cryptographic primitive available in all versions of PHP
# currently in use. To implement our own low-level crypto
# in PHP would result in much worse performance and
# consequently in lower iteration counts and hashes that are
# quicker to crack (by non-PHP code).
if (PHP_VERSION >= '5') {
$hash = md5($salt . $password, TRUE);
do {
$hash = md5($hash . $password, TRUE);
} while (--$count);
} else {
$hash = pack('H*', md5($salt . $password));
do {
$hash = pack('H*', md5($hash . $password));
} while (--$count);
}

$output = substr($setting, 0, 12);
$output .= $this->encode64($hash, 16);

return $output;
}

function gensalt_extended($input)
{
$count_log2 = min($this->iteration_count_log2 + 8, 24);
# This should be odd to not reveal weak DES keys, and the
# maximum valid value is (2**24 - 1) which is odd anyway.
$count = (1 << $count_log2) - 1;

$output = '_';
$output .= $this->itoa64[$count & 0x3f];
$output .= $this->itoa64[($count >> 6) & 0x3f];
$output .= $this->itoa64[($count >> 12) & 0x3f];
$output .= $this->itoa64[($count >> 18) & 0x3f];

$output .= $this->encode64($input, 3);

return $output;
}

function gensalt_blowfish($input)
{
# This one needs to use a different order of characters and a
# different encoding scheme from the one in encode64() above.
# We care because the last character in our encoded string will
# only represent 2 bits. While two known implementations of
# bcrypt will happily accept and correct a salt string which
# has the 4 unused bits set to non-zero, we do not want to take
# chances and we also do not want to waste an additional byte
# of entropy.
$itoa64 = './ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';

$output = '$2a$';
$output .= chr(ord('0') + $this->iteration_count_log2 / 10);
$output .= chr(ord('0') + $this->iteration_count_log2 % 10);
$output .= '$';

$i = 0;
do {
$c1 = ord($input[$i++]);
$output .= $itoa64[$c1 >> 2];
$c1 = ($c1 & 0x03) << 4;
if ($i >= 16) {
$output .= $itoa64[$c1];
break;
}

$c2 = ord($input[$i++]);
$c1 |= $c2 >> 4;
$output .= $itoa64[$c1];
$c1 = ($c2 & 0x0f) << 2;

$c2 = ord($input[$i++]);
$c1 |= $c2 >> 6;
$output .= $itoa64[$c1];
$output .= $itoa64[$c2 & 0x3f];
} while (1);

return $output;
}

function HashPassword($password)
{
$random = '';

if (CRYPT_BLOWFISH == 1 && !$this->portable_hashes) {
$random = $this->get_random_bytes(16);
$hash =
crypt($password, $this->gensalt_blowfish($random));
if (strlen($hash) == 60)
return $hash;
}

if (CRYPT_EXT_DES == 1 && !$this->portable_hashes) {
if (strlen($random) < 3)
$random = $this->get_random_bytes(3);
$hash =
crypt($password, $this->gensalt_extended($random));
if (strlen($hash) == 20)
return $hash;
}

if (strlen($random) < 6)
$random = $this->get_random_bytes(6);
$hash =
$this->crypt_private($password,
$this->gensalt_private($random));
if (strlen($hash) == 34)
return $hash;

# Returning '*' on error is safe here, but would _not_ be safe
# in a crypt(3)-like function used _both_ for generating new
# hashes and for validating passwords against existing hashes.
return '*';
}

function CheckPassword($password, $stored_hash)
{
$hash = $this->crypt_private($password, $stored_hash);
if ($hash[0] == '*')
$hash = crypt($password, $stored_hash);

return $hash == $stored_hash;
}
}

?>

-- modified at 12:50 Thursday 15th November, 2007

pmarfleet15-Nov-07 7:21

15-Nov-07 7:21

This forum is for asking specific VB(.NET) questions. No one is going to do your work and convert your PHP code for you. You should research the classes in the System.Security.Cryptography namespace.

Paul Marfleet

"No, his mind is not for rent
To any God or government"
Tom Sawyer - Rush

LegionFX15-Nov-07 8:00

LegionFX

15-Nov-07 8:00

i dont need nobody to make my work, i just need someone tell where to start!!!!!
where to find some references related to this!! just that!

pmarfleet15-Nov-07 9:26

15-Nov-07 9:26

Search CodeProject, search the web. Then come back when you've got a more specific question to ask.

BTW, it's unlikely that anyone is going to understand your PHP code if you post it in a Visual Basic forum!

Paul Marfleet

"No, his mind is not for rent
To any God or government"
Tom Sawyer - Rush

How to retreave text from ASP.net or HTMl to sql table

DigiOz Multimedia15-Nov-07 11:39

DigiOz Multimedia

15-Nov-07 11:39

Take a look at this thread on PHPBB support forum (if you haven't seen it already):

http://www.phpbb.com/community/viewtopic.php?f=71&t=585387&st=0&sk=t&sd=a[^]

I am actually working on something similar to what you are looking for, trying to translate the Hashing Class to its VB.NET equivalent. Contact me at webmaster@digioz.com and maybe we can work on it together.

Pete Soheil
DigiOz Multimedia
http://www.digioz.com

Window Order?

Violinboy215-Nov-07 5:22

Violinboy2

15-Nov-07 5:22

Hi! I am new here so please forgive me of being a noob. I have a question though a friend and I are trying to make a new and better toolbar instead of the mac and xp one. We would like to know is it possible to keep windows made with vb.net in an absolute order
and is it possible to have three windows made into one without moving or closing the space in between? Sorry for not explaining well it's hard to describe. Anyway if you guys could help that would be great!

Re: Window Order?

Violinboy218-Nov-07 5:40

Violinboy2

18-Nov-07 5:40

ok.....

Vimalsoft(Pty) Ltd15-Nov-07 4:28

Vimalsoft(Pty) Ltd

15-Nov-07 4:28

hi all

i want to retreave text that has COlumns from sn html page.in that html page there is a table like this,

UnitNumber|Ownwer |Title Deed|Registration_date| Purchase_Price |Details
========================================================================
1          James   ST545454    20071115          $154000000       Yes
           Bond

.

So thats how my html looks like, so i want to retreave this data and put in in a SQL table. i have already created the table. i want to know how to do it in vb.net

Thanks

Vuyiswa Maseko,

Sorrow is Better than Laughter, it may Sadden your Face, but It sharpens your Understanding

VB.NET/SQL7/2000/2005
http://vuyiswamb.007ihost.com
http://Ecadre.007ihost.com
vuyiswam@tshwane.gov.za

Re: How to retreave text from ASP.net or HTMl to sql table

pmarfleet15-Nov-07 7:13

Re: How to retreave text from ASP.net or HTMl to sql table

15-Nov-07 7:13

You'll have to parse the HTML to get the values for each row. You could do this with regular expressions or with some string manipulation.

Why are you doing this though? Unless you are writing a screen-scraping application, it doesn't seem like a good idea.

Paul Marfleet

"No, his mind is not for rent
To any God or government"
Tom Sawyer - Rush

Vimalsoft(Pty) Ltd15-Nov-07 19:16

Vimalsoft(Pty) Ltd

15-Nov-07 19:16

hi pmarfleet

Thanks for your reply

There is a website that we look at to retrieve information, but now its time consuming to do the copy and paste, we were thinking of writting a Program that will extract that info and put it in a SQl table for us.

How can we achieve this?

Thanks

Re: How to retreave text from ASP.net or HTMl to sql table

pmarfleet15-Nov-07 19:43