keyword this

[PauloFor]

In this code :

public abstract class DCMenuAgrupado

{

Object x = this;

}



Why I can t use keyword 'this' ?

compile error : Keyword this is not available in the current context




Thanks.

[Peter van der Goes]

Re: keyword this


"PauloFor" <paulofor@uol.c om.br> wrote in message
news:eVGUWAmYFH A.3616@TK2MSFTN GP15.phx.gbl...[color=blue]
> In this code :
>
> public abstract class DCMenuAgrupado
>
> {
>
> Object x = this;
>
> }
>
>
>
> Why I can t use keyword 'this' ?
>
> compile error : Keyword this is not available in the current context
>
>[/color]
The this keyword is a reference (pointer) to the current object. The lone
executable statement you cite in your class definition is not within a
method, which is probably causing the problem. Another potential sticking
point is that your class is abstract, and thus, cannot be instantiated. How
can there be a current object?
See what happens if you try something like this (no pun intended):

public class MyClass
{
public void myMethod()
{
// put you code here
}
}

--
Peter [MVP Visual Developer]
Jack of all trades, master of none.

[Jon Skeet [C# MVP]]

Re: keyword this

Peter van der Goes <p_vandergoes@t oadstool.u> wrote:[color=blue]
> The this keyword is a reference (pointer) to the current object. The lone
> executable statement you cite in your class definition is not within a
> method, which is probably causing the problem.[/color]

Indeed. You can't use "this" for an instance variable initialiser.
[color=blue]
> Another potential sticking
> point is that your class is abstract, and thus, cannot be instantiated. How
> can there be a current object?[/color]

By there being an instance of a derived class.


However, you *can* use "this" in a constructor, achieving much the same
result as an instance variable initialiser. In other words, from:

public abstract class DCMenuAgrupado
{
Object x = this;
}

to

public abstract class DCMenuAgrupado
{
Object x;

public DCMenuAgrupado( )
{
x = this;
}
}

--
Jon Skeet - <skeet@pobox.co m>

http://www.pobox.com/~skeet

If replying to the group, please do not mail me too

[Bill Butler]

Re: keyword this


"Jon Skeet [C# MVP]" <skeet@pobox.co m> wrote in message
<snip>[color=blue]
> public abstract class DCMenuAgrupado
> {
> Object x;
>
> public DCMenuAgrupado( )
> {
> x = this;
> }
> }
>[/color]


I am a bit confused.
Other then providing an alias for "this", what is the point?

So....Why would you want to do this?

Bill

[Jon Skeet [C# MVP]]

Re: keyword this

Bill Butler <qwerty@asdf.co m> wrote:[color=blue]
> <snip>[color=green]
> > public abstract class DCMenuAgrupado
> > {
> > Object x;
> >
> > public DCMenuAgrupado( )
> > {
> > x = this;
> > }
> > }[/color]
>
> I am a bit confused.
> Other then providing an alias for "this", what is the point?
>
> So....Why would you want to do this?[/color]

One example might be for a SyncRoot property, which defaulted to
"this" but which could be set to something else.

That's the only thing I can immediately think of, but we'd have to ask
the OP :)

--
Jon Skeet - <skeet@pobox.co m>

http://www.pobox.com/~skeet

If replying to the group, please do not mail me too