C# Discussion Boards - CodeProject

Ingo30-Jan-06 22:59

30-Jan-06 22:59

If you need a unique hashcode that doesn't depend on the properties try the timestamp instead or you can use guid instead of calculating them on your own.

Greetings,
Ingo

Re: Hashcodes

Le centriste31-Jan-06 1:52

Le centriste

31-Jan-06 1:52

Be aware that if comparison of instances return true, like in:

obj1.Equal(obj2) == true

then they must return the same hashcode.

obj1.Hahscode() == obj2.hashcode()

So, if you implement your own hashcode that is unique for every instance, make sure to override the Equal method to always return false.

If you don't do that, your class won't be usable in Arrays and Hashtables.

--------

"I say no to drugs, but they don't listen."
- Marilyn Manson

Re: Hashcodes

Beringer31-Jan-06 12:23

Beringer

31-Jan-06 12:23

Thanks for all the suggestions.
Much appreciated.
Eric

Question on running Excel when multiple versions of Excel are installed

Flack30-Jan-06 9:13

Flack

30-Jan-06 9:13

Hello,

Lets say I built my app on a machine that has Excel 2003 installed. So, the interop assembly created was built off of 2003.

Now, I have a few questions on what would happen if I ran the following code on a machine that had, lets say, both Excel 2000 and Excel 2003 installed.

using Microsoft.Office.Interop.Excel;
...
ApplicationClass app = new ApplicationClass();
MessageBox.Show(app.Version);
app.Quit();
...

1. If the user has both Excel 2000 and Excel 2003 installed, which one will be started? Will it always start the latest version?

2. If no Excel is installed at all, would app be null after the call to new ApplicationClass() or would that call not even be able to run?

Thanks.

I need a csc switch

likefood30-Jan-06 9:12

likefood

30-Jan-06 9:12

I'm trying to compile a little C# program with the commandline csc compiler. I'm using the [DLLImport()] attribute, so I need the System.Runtime.InteropServices namespace, right? Problem is, csc wants to know what assembly it's from (there's no DLL named System.Runtime.InteropServices.dll). I need it for the /r: switch for csc.exe. Anyone?

Re: I need a csc switch

Guffa30-Jan-06 9:18

Guffa

30-Jan-06 9:18

Mscorlib.dll

---
b { font-weight: normal; }

Re: I need a csc switch

likefood30-Jan-06 9:26

likefood

30-Jan-06 9:26

I saw that one mentioned in the MSDN article for the attribute, but, when I use it, csc gives me the following error (the same as if I had not used it)...

[file and location]: error CS0246: The type or namespace name 'DLLImport' could not be found (are you missing a using directive or an assembly reference?)

Am I misspelling something?

By the way, I appreciate the help. Thank you!

Re: I need a csc switch

likefood30-Jan-06 9:30

likefood

30-Jan-06 9:30

Ok, I see what I did. I accidentally capitalized the two L's in "DLLImport". Now that I feel like a complete moron, I'll back out of here now. Thank you very much for the help! This place rocks!

Controlling the listView's scrollbar with another control.

galinace30-Jan-06 8:17

galinace

30-Jan-06 8:17

Hi,

I'm working on a control contains two listviews which are arranged vertically.
I would like to synchronise them to make them appear like just one listview.
(they "view" are set to detail, columnStyle is set to "none" for one and to "Clickable" for the other one.)
I had allready synchronized the width changing of columns but I can find a way of managing the scrollbar.

I would like scrollbar doesn't appear in one listview and would be manage with the other one.

Is there anyone who can help me please ?

Sincerly

How to close opened TCP connection?

Petrus_Alex30-Jan-06 7:13

Petrus_Alex

30-Jan-06 7:13

I'm using class Net.Socket to establish internet connection. Everything is OK, but I can't close the connection.
Methods .ShutDown(...) and .Close() do not help me - the connection is still alive, after calling these methods.

My code:
/////////////////////////////////////////////

_sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
IPAddress address = hosts.AddressList[0];
IPEndPoint ipep = new IPEndPoint(address, port);

try
{
_sock.Connect(ipep);
}
catch(Exception sockex)//(SocketException sockex)
{
}

// CLOSING

_sock.Blocking = false;
_sock.Shutdown(SocketShutdown.Both);
_sock.Close();

Re: How to close opened TCP connection?

Judah Gabriel Himango30-Jan-06 7:19

Judah Gabriel Himango

30-Jan-06 7:19

I would think Close should. Did you try Disconnect?

Rather than swallowing exceptions, you might rather use a finally block:

try
{
   _sock.Connect(...);
}
finally
{
    // This block of code will be called regardless of whether an exception occurred.
    _sock.Close();
}

Tech, life, family, faith: Give me a visit.
I'm currently blogging about: Connor's Christmas Spectacular!
Judah Himango

Re: How to close opened TCP connection?

leppie30-Jan-06 8:20

leppie

30-Jan-06 8:20

That really depends if the connection is open or not Smile | :)

Just like one should do for Data connections. But one can never be sure of pesky network errors, hehe Poke tongue | ;-P

xacc.ide-0.1.2 'Milestone' - includes full source
Now supporting 24 languages including F#, FreePascal/Delphi and VB.NET

Shortcut keys

Sled Dog30-Jan-06 6:37

Sled Dog

30-Jan-06 6:37

Hello Everyone,

I am wondering if it is possible to use F9, F10, F11, & F12 as a shortcut key in my web application. I know that IE reserves some of them, but the client would find it useful if we could apply them for the application purpose rather than using Alt+Character.

Has anyone accomplished this without using a 3rd party add-in product?

Thanks for the thoughts-in advance.

SD

Menubar like Skype ... ?

Skoder30-Jan-06 6:29

Skoder

30-Jan-06 6:29

Hey,

i was just wondering, how do i make a menubar like the one in Skype ? (http://www.skype.com/i/screenshots/step1_windows.png[^] - The top one with icons)

It seems like it is just regular buttons, they have used which gets the outline when the mouse is moved over.
But i cant find out how to remove the outline from the buttons when the mouse is not over.
The 3 styles i have all have a outline (standard in .Net 2.0), and doesnt look like the ones in Skype.

Also is the Seperator which is used a standard item ? or is it something they have made themself ?

Martin

Re: Menubar like IE, Outlook, Skype more... ?

Skoder31-Jan-06 4:07

Skoder

31-Jan-06 4:07

Hmm ...

Actually it is not only Skype that have that type of buttons ... also Internet Explorer, Outlook and more uses that type of buttons...

It is just like normal buttons with a Image attached but they dont have the outline, only when the mouse moves over...

I guess they are probably already a part of the .NET 2.0 Framework ...
But how are they made ? what are they called ? i simply cant find out ...

Can anyone help me ?

What should i look for, for creating buttons like that ?

HOW TO USE TIMESTAMP

ventomito30-Jan-06 6:15

ventomito

30-Jan-06 6:15

Hi everybody!
I've got a problem: (C# 2005)

I'm writing an applitcation that menage a database. I want to use the timestamp method to make the update to the database. I've alreay added to each relation in my database a column with a timestamp value. I know i must modify the text of the update command in the table adapter but i dont know how...
please help me!

thank you in advance
Enrico

VentoEngine corp.
Program your life ^^

Data Adapter ??

VPMahank30-Jan-06 5:29

VPMahank

30-Jan-06 5:29

I installed VS2005 very recently. Where is the DataAdapter( all types sql,ole) object which usually shows up under the Data tab in the ToolBox in VS2005. Any help or links would be greatly appreciated.

Thanks
VPMahank.

Message Box in C#

idreesbadshah30-Jan-06 4:27

idreesbadshah

30-Jan-06 4:27

I m using ASP.net with C#.I want to dispaly a message box just like we do "Alert('this is message')" in javascript.But i want to show such a message box or dialogue box in asp.net with C#.what should i do because its not a windows form

Re: Message Box in C#

Alvaro Mendez30-Jan-06 5:46

Alvaro Mendez

30-Jan-06 5:46

Do you want to show the message box on the browser? If so, alert('message') does it. Remember that JavaScript is case sensitive so it needs to be alert not Alert. If you want to show it on the server, then you can't because it would freeze the server until someone clicked OK.

Regards,
Alvaro

Re: Message Box in C#

ventomito30-Jan-06 9:46

ventomito

30-Jan-06 9:46

Maybe this can help

<br />
MessageBox.Show("Error message", "Name Entry Error", MessageBoxButtons.OK,MessageBoxIcon.Exclamation);<br />

VentoEngine corp.
Program your life ^^

Re: Message Box in C#

Dave Kreskowiak30-Jan-06 13:56

Dave Kreskowiak

30-Jan-06 13:56

Won't work in an ASP.NET app. MessageBox is only part of the Windows.Forms namespace.

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

Re: Message Box in C#

luckyv1-Feb-06 6:29

luckyv

1-Feb-06 6:29

hi,

You can write code in java script and use 'Registerstartupscript' for implementing that script.

lucky Smile | :)

UserControl Problem w/Exposing Property

MarkMokris30-Jan-06 4:19

MarkMokris

30-Jan-06 4:19

I have created my own composite control, a "Color Check Box". I derived from UserControl and added a Picture Box (ColorCheckBoxButton) and a Label (ColoeCheckBoxLabel). I want the composite control to expose the Text property. The UserControl class already has a Text property, so I figure I must override it with the following code:

[Category("Appearance")]<br />
public override String Text<br />
{<br />
        get { return ColorCheckBoxLabel.Text; }<br />
	set { ColorCheckBoxLabel.Text = value; }<br />
}

Programitically this works and I can assign the Text property when I use the composite control. However, the Text property of the compiste control does not seem to be exposed in the Properties window of the VS designer when I user the composite control from the Toolbox. There appears to be NO Text property.

What am I doing wrong?

Thanks!

Mark Mokris

Re: UserControl Problem w/Exposing Property

kasik30-Jan-06 5:09

kasik

30-Jan-06 5:09

The Text property of the UserControl class has its Browsable attribute set to false, so you will need to add it (however this will create some serialization issues, so you will also need to add a DesignerSerializationVisibility attribute, set to Visible)...

[
Category("Appearance"),
Browsable(true),
DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)
]
public override String Text
{
    get { return ColorCheckBoxLabel.Text; }
    set { ColorCheckBoxLabel.Text = value; }
}

Cheers,
Will H

-- modified at 11:15 Monday 30th January, 2006

Re: UserControl Problem w/Exposing Property

MarkMokris30-Jan-06 6:01

MarkMokris

30-Jan-06 6:01

Thanks Wil! That worked! How would I ever have found that?

One more question. How do I change the Text property in the parent class (UserControl) now that I have overridden the Text Accessor method. If I do the following, it results in a stack overflow, because the parent accessor method is called recursively:

[Category("Appearance")]<br />
[Browsable(true)]<br />
[DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]<br />
public override String Text<br />
{<br />
    get { return ColorCheckBoxLabel.Text; }<br />
    set { ColorCheckBoxLabel.Text = value; this.Text = value;}<br />
}

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