Re: Timer + Thread = what? - C# Discussion Boards

leppie1-Jul-03 6:59

leppie

1-Jul-03 6:59

Alex Kucherenko wrote:
Wrong!

Why?

Alex Kucherenko wrote:
in net we have such classes: SystemPens, SystemBrushes and etc.

Your class does not check is requiered Pen or Brush can be replaced by System version, which are exist as singleton instance for hole application and does not use additional GDI Objects.

Thats exactly what I am simulating...and those singletons DONT exist unless they are used.

leppie ::AllocCPArticle(Generic DFA State Machine for .NET);

Re: GDI Tip of the Day

Nathan Blomquist1-Jul-03 2:14

Nathan Blomquist

1-Jul-03 2:14

Shouldn't this class implement IDisposable? I mean the objective of this class is to create and maintain pens and brushes; these need to be destroyed, right?

-Nathan

---------------------------
Hmmm... what's a signature?

Re: GDI Tip of the Day

leppie1-Jul-03 7:04

leppie

1-Jul-03 7:04

If they are bound to a single control, then maybe, but if they are part of the whole application they will simply get disposed when the application is exited.

leppie ::AllocCPArticle(Generic DFA State Machine for .NET);

about WebBrowser in mdi

benzite30-Jun-03 15:02

benzite

30-Jun-03 15:02

Hi,;)

When a webbrowser is embeded in a child window,the browser can not respond to user.What can I do to make the browser work correctly as it is embeded in a single form?

Many Thanks.

ListView Column Width

.gonad30-Jun-03 14:33

.gonad

30-Jun-03 14:33

Hi guys...

does anyone know of a way to have the columns in a list view auto adjust to the width of the data in a column?

Right now, i have to manually adjust the column header to see the entire data.

Thanks,
.gonad.

.gonad.

Print a web page

nahumtakum30-Jun-03 11:08

nahumtakum

30-Jun-03 11:08

Hi There !

I am trying to develop a control which will be added to web pages and will allow to make "friendly print".

I have tried to look for something similar and couldn't find anything.

I have found some answers dealing with css, which includes the lines:

img{ visible:none}

It allows me to print only some of the elements.

I want to create header and footer of my own.

I have read this article, which is aproposal of standard for css, which I'm afraid wasn't carried out.

(http://www.pwg.org/xhtml-print/HTML-Version/CSS-Print.html)

@page {
counter-increment: pages;
@bottom{ font-family: Times, Palatino, serif;
font-size: 80%;
font-weight: normal;
text-align: center;
content: "Page " counter(pages);
}
}

Does anyone has any idea what to do ? (without handling the registry...)

Timer + Thread = what?

RB@Emphasys30-Jun-03 7:43

RB@Emphasys

30-Jun-03 7:43

Hey All,

Im looking for some advice. I have written a little thread that will check to see wether a text file has been updated. It compares the time for example. I as wondering, whats the best way to have a thread execute a method every few seconds without completely bogging down my main thread?

Thanks,
Ryan

Re: Timer + Thread = what?

J. Dunlap30-Jun-03 7:57

J. Dunlap

30-Jun-03 7:57

Have that thread manage the timer (start it, stop it, etc.). If the file has changed, you can Invoke() a method so that it will run on the main thread.

You might want to check into the FileSystemWatcher. It doesn't work in Win9x/ME, though. Dead | X|

"Blessed are the peacemakers, for they shall be called sons of God." - Jesus

"You must be the change you wish to see in the world." - Mahatma Gandhi

Re: C# Memmory allocation

Nemanja Trifunovic30-Jun-03 6:38

Nemanja Trifunovic

30-Jun-03 6:38

On the stack.

Re: C# Memmory allocation

leppie30-Jun-03 9:22

leppie

30-Jun-03 9:22

zhyluo2003 wrote:
where is a's memory allocated? in the stack or heap?

Memory is allocated for all objects (primitives too). GC cleans it up. Note: That unlike C, everything goes onto the managed heap, so one can "dynamically" create a valuetype array. MS recommends using classes above structs for performance reasons.

leppie ::AllocCPArticle(Generic DFA State Machine for .NET);

Re: C# Memory allocation

Wesner Moise30-Jun-03 12:45

Wesner Moise

30-Jun-03 12:45

Structs and other valuetypes such as ints and the like are created on the stack, not on the heap.

Thus, the syntax

int x = new int();

is confusing, because it appears the integer is allocated on the heap when it isn't.

To allocate on the heap, it is necessary to use (object) new int(), to box the valuetype as a heap object. It really is just syntactical sugar.

Valuetype arrays are allocated on the heap, but that's because arrays themselves are objects. But unlike object arrays, valuetype arrays contain the values as inlined elements rather than references.

Managed C++ makes it clear by exposing 2 pointers int __box * and int * to differentiate between boxed valuetypes and the stack-based equivalents.

Valuetypes are faster to operate than objects, but passing valuetypes around can involve an expensive copy operation if the valuetype is large, and are not passed by reference.

You can make your program an order of magnitude using valuetypes, but only if the data type truly exhibits value semantics. On the down side, you do lose a lot of flexibility.

Thanks,
Wes

Re: C# Memmory allocation

Nemanja Trifunovic30-Jun-03 12:54

Nemanja Trifunovic

30-Jun-03 12:54

leppie wrote:
MS recommends using classes above structs for performance reasons.

Suspicious | :suss:

Any links?

Re: C# Memmory allocation

leppie30-Jun-03 13:14

leppie

30-Jun-03 13:14

Boxing is very expensive. Everytime you add a valuetype to an ArrayList for example it gets boxed (and making a typed collection doesnt get rid of it AFAIK). With a class you dont get that. Unfortunately the only place I could find something now, is in the EMCA 335 spec Partition 5

D.3. Type Usage Guidelines
D.3.1. Class Usage Guidelines
• Do favor using classes over any other type (i.e. interfaces or value types)

On the MSDN/C# homepage there is only a very informative article on performance.

leppie ::AllocCPArticle(Generic DFA State Machine for .NET);

Re: C# Memmory allocation

Kannan Kalyanaraman1-Jul-03 1:32

Kannan Kalyanaraman

1-Jul-03 1:32

struct is a value type, so it should be in the stack.

- Kannan

C# Memmory allocation

zhyluo200330-Jun-03 6:30

zhyluo2003

30-Jun-03 6:30

here is the code:

struct SA
{
//definition of the struct
}
...

SA a = new SA();
...

where is a's memory allocated? in the stack or heap?

Thanks.
Smile | :)

Matlab Application

Ahmed Diaa30-Jun-03 6:24

Ahmed Diaa

30-Jun-03 6:24

Can anyone help me in using matlab applications inside c#?
how to access matlab ?
i have tried to add a reference to matlab application COM object , and i found a class MlApp , i used it and found all functions , but when i run the program i have the following exception
"QueryInterface for DIMapp failed"
how can i deal with that?

Active Directory Searching

soloforce30-Jun-03 6:18

soloforce

30-Jun-03 6:18

As I am new to C# programming in general i am finding it very difficult to accomplish the following.

I have simple widow’s forms program with a text box, button and a list box. I need to be able to enter in a group name into the txt box and have all the users of the group be returned into the list box.

I have been going nuts trying to understand Windows Directory Services etc.

Any help would greatly be appreciated.

Peter

How to make Key Logger?

aMIR_bILAL30-Jun-03 5:41

aMIR_bILAL

30-Jun-03 5:41

Hi Every One there:

i have seen a lot of key loggers which record each and every thing which is typed. I need some help in developing this type of application.
if some one have done this sort of work or know about any tutorial over te web then plzz tell me.

Thank you in advance

Best Regards

LinkedLabel in Datagrid

Chris#30-Jun-03 4:47

Chris#

30-Jun-03 4:47

I want to make a linkedlabel Datagrid column, when user click on it, it will bring up another form. I think probably I should write my custom column style. Does anyone have an example for it?

Coloring listview items?

BoozeBomb30-Jun-03 4:41

BoozeBomb

30-Jun-03 4:41

Hi,
I've got a windows form application with a listview control on it. In my list control, I'm going to have some negative numbers from calculations. Does anyone one know how to color a list view item? I'd like to color a subitem in the listview say red, if it's value is a negative number. I'd only want to color certian items, not an entire row in the listview.

Thanks for your help! Wink | ;)

Re: Coloring listview items?

Roland Bär30-Jun-03 4:58

Roland Bär

30-Jun-03 4:58

I,ve done it like this, but for the Main item:

<br />
ListViewItem item = new ListViewItem();<br />
item.UseItemStyleForSubItems = false;  // Can't remember why this ???<br />
item.Text = myValue.ToString();<br />
if(myValue < 0)<br />
item.ForeColor = System.Drawing.Color.Red;

But I think it should work also for a ListViewSubItem Unsure | :~

Hope this helps

Roland

Need help with Regex

viperxp30-Jun-03 4:15

viperxp

30-Jun-03 4:15

Hi...

I am doing an ad blocker in c#. The blocker will remove ads by stripping HTML tags that matches one or more keywords.

Example: these tags will (have to) be stripped...

<a href="http://myserver.com/mydir/ads/page.htm">Test link 1</a> ... [matches keyword '/ads']

<a href="http://myserver.com/mydir/page.htm"><img width=10 height=10 scr=adserve.myserver2.com/sponsor.gif> ... [matches 'adserve']

I am having problem coming up with regular expression pattern to give me the full matching tag, that is, like
<a href="http://myserver.com/mydir/ads/page.htm">Test link 1</a>
....when i am scanning for keyword '/ads'..
of coz the scanning is a loop, and the keyword is stored in a variable .. e.g. strKey.

the pattern : @"<a\s.*\shref=\S*", strKey, @"\S*(>|\s)"
doesnt work as it would return anything between the first "<a" (no qoutes) and the last space.

the pattern: @"href=\S*", strKey, @"\S*(>|\s)"
does not give the result i wanted.

I have tried to refer to MSDN, but things seem complex and beyond my understanding capability. I really hope someone

can help me to come up with the right regex pattern.

the tags i will (have to) examine include ... IMG SRC, A HREF, IFRAME SRC

thanks

Re: Need help with Regex

leppie30-Jun-03 13:32

leppie

30-Jun-03 13:32

add '(' ')' around those patterns

leppie ::AllocCPArticle(Generic DFA State Machine for .NET);

Re: Need help with Regex

viperxp30-Jun-03 19:05

viperxp

30-Jun-03 19:05

Thanks for the reply, but I am still unclear on how to modify my pattern ...

can u please post the full pattern here?

thanks.

Re: Need help with Regex

1-Jul-03 5:22

i mean, can u be more specific? exactly where to add? for which pattern?

my program has to cater to tags like these:
<a href="http://myserver.com/ads/page.htm" >test</a> [note the space]
<a href="http://myserver.com/ads/page.htm" id="1">test2</a>
<a href="http://myserver.com/ads/page.htm"><img width=20 height=20 src=sponsor.gif></a>

<img width=20 height=20 src='sponsor.gif'>

i wanna extract the full tag that matches the keywords, yet accomodate for the loose nature of html.

please advise. i have no experience using regex, and all references i have doesnt seem helpful. msdn library is confusing me... Frown | :(

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