Re: printer related code - C# Discussion Boards

5-Mar-05 6:21

cishi_us wrote:
I will wait for yours response and the code also related to this module..

Lot of thanx for solving my problem

Uhhh.... YOU have to write the code, we're not doing it for you. You solve your own problems, we just help.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Re: printer related code

cishi_us7-Mar-05 1:21

cishi_us

7-Mar-05 1:21

well sir sure i like to take urs help...i have just reaced to my destiny as well but some problems occuring in it.....
i m writing here u code and plz try to help me...The problem occuring on following places..please read code i m writing where the problem is occuring..

///////////////////////////////////////////////////////////////////

try
{

PropertyDataCollection __gc *pdc = e->NewEvent->get_Properties();
PropertyDataCollection::PropertyDataEnumerator __gc *pdce = pdc->GetEnumerator();
while(pdce->MoveNext())
{
PropertyData __gc *pd = pdce->get_Current();
ManagementBaseObject __gc *mbo = dynamic_cast<managementbaseobject *="">(pd->get_Value());
1) problem***************problem occuring on the below if statement.not all time but some time the mbo variable does not declare and by using watches i see that mbo is undeclared value.its some time ... and printer does not pause..***********************************

if( mbo != NULL && mbo->ClassPath->ToString()->ToUpper()->EndsWith(S"WIN32_PRINTJOB") )
{
/////

//pause job
long a=0;
long *hprinter = &a;
for(int i=0 ; i<this->printersname->Length ; i++)
{
try
{

int result = PrinterAPIs::OpenPrinter(this->printersname[i], hprinter, NULL);
bool resultf = PrinterAPIs::SetJob(*hprinter, (long)Int64::Parse( mbo->Properties->get_Item(S"Jobid")->Value->ToString() ), 0, NULL, 1);
PrinterAPIs::ClosePrinter(*hprinter);
MessageBox::Show(this, mbo->Properties->get_Item(S"Owner")->Value->ToString());
*****************************************************************************
2) Below message box is not showing the correct number of pages that comes from print status that come in task bar when a pages are going to print.***************************************
MessageBox::Show(this, mbo->Properties->get_Item(S"TotalPages")->Value->ToString());

if(resultf == true)
break;
}

catch(Exception __gc *ex)
{
MessageBox::Show(this, ex->ToString());
ex = NULL;
}

Re: printer related code

Dave Kreskowiak7-Mar-05 11:11

registry editing: NullReferenceException driving me crazy...

7-Mar-05 11:11

You do realize this is the C# forum, right? Visual C++ is over here[^]!!

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

markali5-Mar-05 0:01

markali

5-Mar-05 0:01

Hello,

I'm absolutely new to programming, so please don't be too hard on me...

I'm trying to make a simple form application to hide or show hidden files. When I try to run the application I get a "System.NullReferenceException: Object reference not set to an instance of an object."
I found many topics related to this problem, but I still cannot figure it out.

Here's the code:

partial class Form1 : Form

{
public Form1()
{
InitializeComponent();
}

private void HideFiles()
{
RegistryKey MyKey = Registry.CurrentUser;
MyKey = MyKey.OpenSubKey(".Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced", true);
MyKey.SetValue("Hidden",2);
MyKey.Close();
}

private void ShowFiles()
{
RegistryKey MyKey;
MyKey = Registry.CurrentUser;
MyKey = MyKey.OpenSubKey(".Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced", true);
MyKey.SetValue("Hidden",1);
MyKey.Close();
}

private void ShowButton_Click(object sender, EventArgs e)
{
ShowFiles();
}

private void HideButton_Click(object sender, EventArgs e)
{
HideFiles();
}

}

Re: registry editing: NullReferenceException driving me crazy...

mav.northwind5-Mar-05 0:17

Re: registry editing: NullReferenceException driving me crazy...

5-Mar-05 0:17

NullReferenceException is a very basic exception you get when you declare an object reference but do not assign a value to it (or, in your case, have a method returning null and assigning this null to your reference) and then try to access the non-existing object.

Just debug the code then you'll see where the exception occurrs.
I assume the subkey you're trying to open doesn't exist (it should start with "Software", not ".Software").

mav

markali5-Mar-05 0:33

markali

5-Mar-05 0:33

mav.northwind wrote:
I assume the subkey you're trying to open doesn't exist (it should start with "Software", not ".Software").

Thank you, thank you!!!

The 'dot' did it! Pfff, if I knew that it was that simple...
I presume that once you get a little more experienced, you don't make any more mistakes like that. (I hope...)

Thanks again...

Markali

Re: registry editing: NullReferenceException driving me crazy...

Bahadir Cambel5-Mar-05 4:57

Bahadir Cambel

5-Mar-05 4:57

Though I am not much more experienced than you ,I may say, once you started to face with errors , you learn how to deal with them , esp. using debugger (watch is a great tool btw..), understand and comment on errors, than find the appropriate solution..

Sercurity question

oohungoo4-Mar-05 22:47

oohungoo

4-Mar-05 22:47

I am writing an application that allows user login by windows authentication (includes domain and username).
For example:
Username: MYDOMAIN\MyUser
Domain:MYDOMAIN
If this username is valid, application will check for user's role, if user's role is BUILTIN\Users then this user can do their works.

mav.northwind4-Mar-05 23:00

4-Mar-05 23:00

It's nice that you are writing an application, but what's your question?

Confused | :confused:

mav

Dave Kreskowiak5-Mar-05 9:46

5-Mar-05 9:46

And?

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

oohungoo6-Mar-05 0:24

oohungoo

6-Mar-05 0:24

oops... I am trying to write this application, but I don't know how to write. Sorry, Big Grin | :-D

VS.NET error or my error: if(a<0) a = -a;

J4amieC6-Mar-05 22:37

J4amieC

6-Mar-05 22:37

Right, thats nice, so what's your specific question?

dstang20004-Mar-05 20:12

dstang2000

4-Mar-05 20:12

the code is from my work:
class Test
{
static void Main()
{
int a = 0x79de61c0; //2044617152;
a += 0x12345678;
//a 应为 0x8c12b838; //-1944930248

if( a< 0 ) a = -a;

//string str1 = a.ToString();
System.Console.WriteLine( a );
//string str2 = a.ToString();
}
}
Here: if( a<0 ) a=-a; means a will be positive(>0)
if we use line "str1" or "str2", we get a negative number:
-1944930248。
Why a.ToString() effects the result?

Re: VS.NET error or my error: if(a<0) a = -a;

mav.northwind4-Mar-05 23:17

Re: VS.NET error or my error: if(a<0) a = -a;

4-Mar-05 23:17

I'm not getting a positive number at all, a.ToString() doesn't effect the result.

I think you should be using long instead of int, otherwise you'll be getting overflows all the time and unexpected results if you rely on the sign of your values.

You can use the checked keyword or the /checked compiler flag to detect such overflows.

mav

Luis Alonso Ramos5-Mar-05 19:12

Luis Alonso Ramos

5-Mar-05 19:12

dstang2000 wrote:
if( a< 0 ) a = -a;

And if you want the absolute value, try Math.Abs.

-- LuisR

Luis Alonso Ramos
Intelectix - Chihuahua, Mexico

Not much here: My CP Blog!

Re: VS.NET error or my error: if(a<0) a = -a;

dstang20005-Mar-05 20:59

dstang2000

5-Mar-05 20:59

When I debug, I found it is a terrible bug in JIT.
btw: JIT instruction is correct.
I've asked somebody to report the bug to MS.

logically linked array

lindiwe4-Mar-05 19:36

lindiwe

4-Mar-05 19:36

Hi Guys,

I missed a lecture yesterday and my lecturer was starting a new topic on logically linked arrays.Can you please explain this topic briefly to me with an example using a logically linked array.This will assist me the next time i go to class coz i wont be behind.

uni1985

Re: logically linked array

mav.northwind4-Mar-05 21:45

Re: logically linked array

4-Mar-05 21:45

That's a flame bait if ever I saw one D'Oh! | :doh:

Why don't you ask one of your mates who attended the lecture to explain it to you?

You weren't there and neither were we, so how come you think we can tell you what your professor taught?

Let's reverse the situation: You find out what your professor wants you to know about logically linked arrays and then write an article here so that everybody can learn a valuable lesson.

mav

Dave Kreskowiak5-Mar-05 9:45