C# Discussion Boards - CodeProject

C# Study Group in Los Angeles

3-Sep-02 22:45

Eka wrote:
Is it possible to hide My Computer folder? I would like also to hide A Drive
so people can't use it.

Yes, you can. It is a registry entry somewhere, and if you are using Win 2000/XP , you can run the group policy editor, by running gpedit.msc from start run. Unfortunately, I cant point you to the correct place in the registry.

Hope this helps Smile | :)

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Victor Campos3-Sep-02 11:16

Victor Campos

3-Sep-02 11:16

BACK TO SCHOOL! Means back to studies!!

Have you seen the way VFP works with .NET? Have you played around with .NET at all? Do you want to expand on your arsenal of development tools?

HTTP://www.vwfox.org is proud to present the C# Study Group.

By popular demand and by request of our attendees we've put together an agenda for this class that is not to be missed. Some places will charge you $2000 to $3000 for a five day study course that'll take you 6 months to a year to make any use of - extend your studies to a realistic length of time.

Come spend time studying twice a month with us and learn a new language - C# the newest language from Microsoft's Visual Studio.NET. C# is part of the C evolution. Take advantage of VFP's rich database language in C# through XML and COM/COM+.

The cost of the study course is $50 for six months plus the cost of books (you provide you own laptop). We provide the refreshments and a very nice facility as well as Audio and visual Equipment.

Our First meeting will be September 23, 2002. We want everyone to get the most out of this Class so size is limited - RSVP soon.

For more info go to http://www.options-sc.com/cssg

or contact Victor Campos at victor@options-sc.com and Frank Marafino at frank@atinnovations.com

Victor Campos, President
Options Software Consulting, LLC
victor@options-sc.com

Re: C# Study Group in Los Angeles

leppie3-Sep-02 23:34

Re: C# Study Group in Los Angeles

3-Sep-02 23:34

This is so nice, I feel like moving to LA. Here in South Africa you cant even find .Net related employment. Frown | :(

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David Stone4-Sep-02 12:33

David Stone

4-Sep-02 12:33

Argh! Get a banner ad. Seriously, I hate ad posts. Mad | :mad:

David Stone

But Clinton wasn't a predictable, boring, aging, lying, eloquent, maintainer-of-the-status-quo. He was a predictable, boring-but-trying-to-look-hip, aging-and-fat-but-seemingly-oblivious-to-it, lying-but-in-sadly-blatant-ways, not-eloquent-but-trying-to-make-up-for-it-by-talking-even-more, bringer-in-of-scary-and-potentially-dangerous-new-policies. And there was also Al Gore. It just wasn't *right*.

Shog⁹

The "new" modifier

Paul Riley3-Sep-02 11:16

3-Sep-02 11:16

I'm trying to create a component based on the RichTextBox. One thing I want to do is set some new defaults for the properties.

Now I can do it like this (in the constructor):

this.Multiline = true;
this.ScrollBars = RichTextBoxScrollBars.Both;
this.Font = new Font(System.Drawing.FontFamily.GenericMonospace, 10);
this.WordWrap = false;
this.AcceptsTab = true;

But this doesn't seem to give different defaults, it just overwrites whatever is there... seems kinda tacky.

So instead I'm trying to override the properties. As far as I could gather from the documentation, this can be achieved like this:

new public bool Multiline = true;
new public RichTextBoxScrollBars ScrollBars = RichTextBoxScrollBars.Both;
new public Font Font = new Font(System.Drawing.FontFamily.GenericMonospace, 10);
new public bool WordWrap = false;
new public bool AcceptsTab = true;

It compiles okay but then when I put the component onto a form, it's actually done nothing, the standard RichTextBox defaults are there.

What am I doing wrong???

Paul

leppie3-Sep-02 11:21

3-Sep-02 11:21

Have you looked the DefaultValueAttribute ?

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Paul Riley4-Sep-02 0:10

4-Sep-02 0:10

Hi leppie,

No, I hadn't, but I have now. Unfortunately this:

[DefaultValue(true)]
new public bool AcceptsTab;

seems to do exactly the same as this:

new public bool AcceptsTab = true;

the only purpose for the former seems to be that you can use it on a get/set property structure.

Confused | :confused:

Paul

leppie4-Sep-02 0:29

4-Sep-02 0:29

I think you will have to go by setting the defaults in the constructor...or maybe create a designer??? I have never made a designer, so I will not comment Smile | :)

pdriley wrote:
new public bool AcceptsTab = true;

That would be the same as declaring a new constant Property as far as i can see, making it pretty much useless Eek! | :eek:

Hope you find your solution Smile | :)

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Paul Riley4-Sep-02 0:39

4-Sep-02 0:39

Unfortunately, setting in the constructor will override anything I do to the property page, so that's not all that much use either. Frown | :(

So... what's a designer? Can you give me a clue where to start looking?

Paul

leppie4-Sep-02 0:56

4-Sep-02 0:56

pdriley wrote:
Unfortunately, setting in the constructor will override anything I do to the property page, so that's not all that much use either.

True Frown | :(

Look in System.Windows.Forms.Design, like I said I am not sure...you mite have to override all the properties that u want different defaults.

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Paul Riley4-Sep-02 1:16

4-Sep-02 1:16

Thanks. I'll look at that.

Incidentally, you can't use override either...

public override bool AcceptsTab = true;

will give you an "override is not valid for this item" message.

So I took "override" out and it compiled okay but gave me a warning saying "The keyword new is required on 'MyNameSpace.MyComponent.AcceptsTab' because it hides inherited member 'System.Windows.Forms.TextBoxBase.AcceptsTab'". This is what promptede me to start looking at "new" Frown | :(

Paul

leppie4-Sep-02 7:27

Re: The "new" modifier (solution!)

4-Sep-02 7:27

Hi Paul

use new when u need to change (really overload) the member to have a different return type or protection level.

use override on protected members of an inherited class.

use nothing to hide member, compiler gives warning, but that is ok, we want that. Smile | :)

By overriding , I meant,

public override bool AcceptsTab 
{
  get { return base.AcceptTab;}
  set { base.AcceptTab = true;} //this will allways set it to true, i think
}

Try that... Smile | :)

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Paul Riley4-Sep-02 8:48

Re: The "new" modifier (solution!)

4-Sep-02 8:48

Hi leppie,

I've just got it, and you're part right. Two problems with your idea: (1) I don't want to always set it to true and (2) you can't override AcceptsTab (among other things) because it's not virtual.

Initially, it's actually a lot more simple than you might think. In the component design mode, you can set any of the properties and this drops neatly into the InitializeComponent() function.

This still has a couple of nasty drawbacks though: It still assumes the default is "false", so (1) true shows up as Bold in the form designer and (2) if you set it to false the designer thinks it needs no code, so it doesn't actually override it. You can, of course, change it programmatically but I hate loose ends.

So, after much fiddling, I've discovered that this solves the problem:

[DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
[DefaultValue(true)]
new public bool AcceptsTab
{
	get { return base.AcceptsTab; }
	set { base.AcceptsTab = value; }
}

Nice huh? When I've got this sorted out properly (and figured out how to do the same with a font), it may form a basis for my first article. This is not documented ANYWHERE, it took me ages to figure it out!

Paul

leppie4-Sep-02 9:17

Can't create an Access database in C#?!?!?!

4-Sep-02 9:17

Great

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Marc Clifton3-Sep-02 10:41

Marc Clifton

3-Sep-02 10:41

I want to create an Access database with C#. Did MS leave this out??? I can do this using DAO and C++!!! Not with ADO??? Why not?

Re: Can't create an Access database in C#?!?!?!

Zombies with Coffee, LLC4-Sep-02 9:27

Zombies with Coffee, LLC

4-Sep-02 9:27

Look for Adox. For some reason, they don't talk about it much in any of my books.

Combobox in a Toolbar

Anonymous3-Sep-02 6:07

Anonymous

3-Sep-02 6:07

Does anyone know how to get a ComboBox in a toolbar without using a third party control? I need to use the standard .NET toolbar with a combobox.

ZeroMemory

Nnamdi Onyeyiri3-Sep-02 2:06

3-Sep-02 2:06

Hello, its me again [ Eek! | :eek:

run while you can] Big Grin | :-D

is there a function similar to ZeroMemory i can use?

Suspicious | :suss: Email: theeclypse@hotmail.com URL: http://www.onyeyiri.co.uk
"All programmers are playwrights and all computers are lousy actors."

Rodney S. Foley3-Sep-02 2:13

Rodney S. Foley

3-Sep-02 2:13

There is no equivelent method to the Windows ZeroMemory function in C#. You need to remember that the memory in C# is managed for you. What are you trying to do, maybe I can help you find a solution.

Aalst

Nnamdi Onyeyiri3-Sep-02 7:46

3-Sep-02 7:46

i was trying to convert this[^], and found that it was giving an exception that an instance of an object is not bla bla bla, but i HAVE initisated it Confused | :confused:

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leppie3-Sep-02 2:28

3-Sep-02 2:28

byte buffer = new byte[size]; 
IntPtr ptr = Marshal.AllocHGlobal(size * Marshal.SizeOf(typeof(byte)));
Marshal.Copy(buffer, 0, ptr, size);

I dunno if this will provide the same ?

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Nnamdi Onyeyiri3-Sep-02 7:48

3-Sep-02 7:48

i was converting http://www.codeguru.com/system/cdr.html[^] and foundthat it didnt work, it said that my MCI_OPEN_PARMS variable, was referencing an object that doesnt exist, when it was. the only bit of the C++ code i didnt convert was the ZeroMemory bit, so i presumed that may be the problem.

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Nnamdi Onyeyiri3-Sep-02 8:02

3-Sep-02 8:02

i have discovered that when i changed the second parameter of mciSendCommand from MCI_OPEN to 0, it did not give the error, but nothing happened.

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leppie3-Sep-02 9:51