C# Discussion Boards - CodeProject

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 | :(

Image-Listbox

jphuphilly30-Jun-03 4:13

jphuphilly

30-Jun-03 4:13

Okay, I have a list box that has image file names i want to display the images in another form to allow the user to preview the image before i select it.......could anybody help me!!!

Thanks Alot!!! Big Grin | :-D

Da Intern

Re: Image-Listbox

Manster30-Jun-03 9:03

Manster

30-Jun-03 9:03

This is what I've done for sending data from one form to another. It's along the lines for what you're looking for.

(1). Declare a public object of your child form in your parent form ex:

public FormNumber2 Form2 = new FormNumber2();

(2). Make sure your listbox (m_ListBox) is declared public on the child form so you can set/get it's data from the parent form.

(3). Declare a string at the top of your child form:

public string m_sFileRemoved;

(4). This code needs to be in your child form.

if( m_ListBox.SelectedItems.Count > 0 )
{
string sSelectedItem = m_ListBox.SelectedItem.ToString();

m_sFileRemoved = sSelectedItem ;

m_ListBox.Items.Remove( sSelectedItem );
}

(5). Put this code in your parent form where you want to get and show the selected file from the listbox.

// read 5a below.
Form2.ShowDialog();
string sFileToBeRemoved = Form2.m_sFileRemoved;
this.Focus();

(5a). This will help you add data to the listbox before you show it (since you declared the control public) from the parent form.

this.Form2.m_ListBox.Items.Add( "File info: string" );

Smile | :)

Hope this helps.

Re: Image-Listbox

jphuphilly30-Jun-03 11:08

jphuphilly

30-Jun-03 11:08

okay im lost..............okay i have 8 images that i want to display in another form that pops up after you select an image from a listbox on the parent form. the 8 images are selectable from the parent and i want them to be viewable in the child.

please help me out.........im kinda lost

Da Intern

Re: Image-Listbox

Manster1-Jul-03 3:59

Manster

1-Jul-03 3:59

Ok, I think this is what you're going to want to do.

On the parent form get the selected index of the listbox and pass that into the child form. On the child form take that index id and set that in the imagelist and picturebox controls to display the correct image when that form is loaded.

Parent form code:

int iLBID = listbox1.SelectedIndex;

ChildForm CForm = new ChildForm( iLBID );
CForm.ShowDialog( this );
CForm.Dispose();
this.Focus();

Child form code:

private int m_iSelID;

// Constructor code.
public ChildForm( int iLBID )
{
m_iSelID = iLBID;

pictureBox1.Image = imageList1.Images[m_iSelID];
}

** remember to add a picturebox and an imagelist control to your child form. Load up the imagelist control in design mode and then set the picturebox image index to the index selected in the parent listbox.

Hope this helps. Wink | ;)

Re: Image-Listbox

jphuphilly1-Jul-03 7:27

jphuphilly

1-Jul-03 7:27

This is whats in my parentForm:

		private void tbimage_SelectedIndexChanged(object sender, System.EventArgs e)<br />
		{<br />
<br />
		<br />
<br />
			switch (tbimage.SelectedIndex) <br />
			{<br />
				case 0 :<br />
					myImgForm.pBox1.Image = Image.FromFile("magic5.gif");<br />
					break;<br />
				case 1 :<br />
				myImgForm.pBox1.Image = Image.FromFile("magic5.gif");<br />
					break;<br />
				case 2 :<br />
				myImgForm.pBox1.Image = Image.FromFile("magic5.gif");<br />
					break;<br />
				case 3 :<br />
					myImgForm.pBox1.Image = Image.FromFile("magic5.gif");<br />
					break;	<br />
				case 4:<br />
					myImgForm.pBox1.Image = Image.FromFile("magic5.gif");<br />
					break;<br />
				case 5 :<br />
					myImgForm.pBox1.Image = Image.FromFile("magic5.gif");<br />
					break;<br />
				case 6 :<br />
					myImgForm.pBox1.Image = Image.FromFile("magic5.gif");<br />
					break;<br />
				case 7 :<br />
					myImgForm.pBox1.Image = Image.FromFile("magic5.gif");<br />
					break;	<br />
				case 8 :<br />
					myImgForm.pBox1.Image = Image.FromFile("magic5.gif");<br />
					break;<br />
			}

My parent Form is called FmMain

MyChild Form is called PreImg

My Picture Box is called pBox1

My Combo Box is called tbimage

My imagelist is called imagelist1

please help

just tell me when im gettin annoying

im just tryin to get through this final part Big Grin | :-D

Da Intern

Re: Image-Listbox

jphuphilly30-Jun-03 11:35

jphuphilly

30-Jun-03 11:35

How do i use this....................okay, i have a form that has a list of file names, when those file names are selected i want a seprate form to pop-up showing each selected image. so if i selected image 1 then a form should pop-up showing image 1.

Please help

P.s. i've done alot already i think my brain is on "E", so could please help!!!

Thanks Big Grin | :-D

Da Intern

who knows sth. about FolderNameEditor?

gongxiancao30-Jun-03 2:48

gongxiancao

30-Jun-03 2:48

and its member function? WTF | :WTF:

Toolbars, main menus & context menus

hbandarra29-Jun-03 23:48

hbandarra

29-Jun-03 23:48

I have several lists with different items. All of them should have copy, cut paste, delete and custom capabilities working from context menus, main menu and toolbar.

If no item of a given type is selected, the buttons and menus entries for that kind should be grey.

When selecting an item the menus and items should change accordingly.

When choosing a menu entry or toolbar button, the action should be applied to the selected item.

Basically, have the same behaviour office or developer studio have.

What is the best way of implementing such thing?
Who’s responsible to recognize the selected item? How?
How do I apply actions over the selected Item? Using events?
Does Visual Studio or .Net framework natively support a specific way of solving this?

Thanks.

Re: Toolbars, main menus & context menus

hbandarra30-Jun-03 3:19

hbandarra

30-Jun-03 3:19

Microsoft solves this problem by using a Command Manager class:
http://msdn.microsoft.com/library/default.asp?url=/msdnmag/issues/02/10/commandmanagement/TOC.ASP

Deserializing dynamically loaded types

Oyvind Bratland29-Jun-03 22:26

Oyvind Bratland

29-Jun-03 22:26

I have created a diagram building application (something
like a "diet Visio" Poke tongue | ;-P

) with an abstract Shape class every
drawing shape have to inherit.

My program has plug-in support so users can create their
own shapes (derived from my abstract Shape class). The
plug-ins are placed in a separat folder. The dll files in
this folder are dynamically loaded at startup.

Of course, I want my program to be able to save and load a
drawing. I use the BinaryFormatter and Stream classes to
serialize the drawing. This looks ok, but when I
deserialize the same file, I get an exception
(i.e) "Rectangle.dll not found" (or something like that),
because this file is a plug-in, dynamically loaded at
startup.

So (finally) my question is: What is the best way to
serialize and deserialize an object (consisting of
dynamically loaded objects) like my drawing object?

Any help and suggestion are appreciated.

Øyvind.

opacity of panels

Member 138827529-Jun-03 21:39

Member 1388275

29-Jun-03 21:39

Hi,

I'm trying to get several browser panels on top of each other each with a different opacity. I was wondering if there was any way of setting the opacity for a panel, or if any one had any ideas as to how to go about achieving this effect.

thanks
dror.

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