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An enigma rapped up in a puzzle inside a....

29-Aug-02 0:40

Does your class have a default contructor ie one that does not take any arguements? If not, that should solve it, else I cant help you Smile | :)

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Nnamdi Onyeyiri28-Aug-02 21:52

28-Aug-02 21:52

ok, i dont think it is that much of a puzzle, but i was thinking last night Eek! | :eek:

if absolutly everything in .NET is ultimatly of type System.Object, what type is System.Object?

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

leppie28-Aug-02 22:08

28-Aug-02 22:08

object is the mother of all classes.

Nnamdi Onyeyiri wrote:
what type is System.Object?

it's an object type Smile | :)

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Nnamdi Onyeyiri28-Aug-02 23:18

28-Aug-02 23:18

but how can a class be of type itself Confused | :confused:

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

leppie28-Aug-02 23:58

28-Aug-02 23:58

When u write:

class MyClass {<br />
}

it's really:

class MyClass : object {<br />
}

Thats understood.

now for example:

MyClass myclass = new MyClass();

now

(myclass.GetType() == typeof(MyClass)) = true

Similarly:

object myobject = new object;

now

(myobject.GetType() == typeof(object)) = true

Hope u understand...I wouldnt have sleepless nites though Smile | :)

MYrc : A .NET IRC client with C# Plugin Capabilities. See
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Nnamdi Onyeyiri29-Aug-02 1:13

29-Aug-02 1:13

i understand, i just didnt think you could do:

class MyClass : MyClass {<br />
}

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

leppie29-Aug-02 1:41

29-Aug-02 1:41

That will throw an compiler error as it is a duplicate definition.

You can however do this:

class MyClass : SomeOtherNamespace.MyClass {<br />
}

as the context for each MyClass is different Smile | :)

MYrc : A .NET IRC client with C# Plugin Capabilities. See
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Nnamdi Onyeyiri29-Aug-02 2:26

29-Aug-02 2:26

so there are more than one object classes each with the other as the base class?

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

leppie29-Aug-02 3:04

29-Aug-02 3:04

OK I think I know what u are getting to, the answer lies in inheritance.

class Base : object //this is not necessary as u know
{
public string Name {get;set}
}

Now Base class will inherit (iow have) all of it's base class's (object or System.Object, same thing) public and protected members.

class MyClass : Base
{
public int Value {get;set;}
public void DoStuff();
}

Now MyClass will get all of Base's public and protected methods, but remember Base has inherited some members from object as well, so it gets those as well.

It can get very confusing, I know. Designing a good class hierarchy takes time, only certain aspects might be affected at each level, but in the end all the inherited properties will be "visible" from top (most specialized class) to bottom (object). Look at the Form class and see how many members are actually inherited.

So in the end there can be only one! The same object class is used everywhere in .NET.

Hope this helps Smile | :)

MYrc : A .NET IRC client with C# Plugin Capabilities. See
http://sourceforge.net/projects/myrc for more info. Big Grin | :-D

Anonymous29-Aug-02 3:56

Anonymous

29-Aug-02 3:56

never mind, you didnt understand what i said, my qq has been aswered in a later post by someone else. [look below]

BTW what i said was, from wot u said, i thought it was declared by

class objectBase : object {}

class object : objectBase {}

Smile | :)

but never mind.

Working with frames in ASP .NET

Philip Fitzsimons29-Aug-02 2:48

Philip Fitzsimons

29-Aug-02 2:48

its not of any type - its a class with no parent.

"When the only tool you have is a hammer, a sore thumb you will have."

Mazdak28-Aug-02 21:30

Mazdak

28-Aug-02 21:30

hi I have three Webforms in one page (with frames)
when one button on one of them is clicked a page
should be load in the other frame, I gotta do it in
codebehind (I know the old HTML way)

Mazy

"If I go crazy then will you still
Call me Superman
If I’m alive and well, will you be
There holding my hand
I’ll keep you by my side with
My superhuman might
Kryptonite"Kryptonite-3 Doors Down

Shutdown, Restart and Logout...

Eka28-Aug-02 19:59

Eka

28-Aug-02 19:59

Hi all,

What is the command in .NET Framework, to do Shutdown, Restart and Logout from Windows?

Thanks for the help..

Eka

new trouble occur,I can't get the ico in dll

fftongzhi28-Aug-02 16:51

fftongzhi

28-Aug-02 16:51

I made a invisible control,and add a ico to it (by [[ToolboxBitmapAttribute("iconfile.ico")])
then I set the ico file as embed resource。at MSDN it said you can use projectname.filename.ext to access the resource embeded in a dll.
but I use [ToolboxBitmapAttribute(typeof(projectname.iconfile.ico))]or
[ToolboxBitmapAttribute("projectname.iconfile.ico")] ,it also can not access the icofile.
What shall I do????

lost my way

Re: new trouble occur,I can't get the ico in dll

James T. Johnson28-Aug-02 19:21

James T. Johnson

28-Aug-02 19:21

I don't believe you can use icon files for the ToolboxBitmap Wink | ;)

Add the bitmap to the project, open up the properties panel (if it isn't already open) and change the Build Type for the icon to "Embedded Resource". The bitmap filename also needs to be named the same as the control, without the default namespace prepended.

Now change the ToolboxBitmap attribute to read.

[ToolboxBitmap(typeof(MyControl))] where MyControl is the name of the control.

James
"And we are all men; apart from the females." - Colin Davies

Re: new trouble occur,I can't get the ico in dll

fftongzhi28-Aug-02 21:11

fftongzhi

28-Aug-02 21:11

Thank you very much!It works well now.
And useing ToolBoxBitmapAttribute really can load a ico file,but it is useless by use typeof(MyControl);bitmap is exact.
Thanks again.;)
This is a good place to discuss programing technique.

lost my way

Can anyone recommend a book for writing custom control in C#?

Li-kai Liu (Angus)28-Aug-02 16:19

Li-kai Liu (Angus)

28-Aug-02 16:19

Any good ideas of what to buy in regard to writing custom control?
I'm looking for a book that explains the ins and outs of Control class,
like when to override createParams, WndProc.

I also saw a few books:

.NET Windows Forms Custom Controls
by Richard L. Weeks, Richard L Weeks

GDI+ Programming: Creating Custom Controls Using C#
by Eric White, Chris Garrett (Contributor)

are they good??

Re: Can anyone recommend a book for writing custom control in C#?

Nnamdi Onyeyiri28-Aug-02 21:50

Re: Can anyone recommend a book for writing custom control in C#?

28-Aug-02 21:50

i have read only

Programming Windows With C# by Charles Patzold Clickety[^]

and havce found it a very good resource for information.

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

Li-kai Liu (Angus)28-Aug-02 22:11

Li-kai Liu (Angus)

28-Aug-02 22:11

I have one at hand.
I agree with you that this one is a comprehensive guide on GDI+ and how to use these controls. But not in depth when it comes to writing our own controls.

Re: Can anyone recommend a book for writing custom control in C#?

leppie29-Aug-02 0:47