second instance

[Shawn]

how do i prevent the second instance of my app from being instanced when one
is already running?

[Ravikanth[MVP]]

Hi

Singleton assures that there is one and only one instance
of the class and provides a global point of access to
it.There are number of cases in programming where you
need to make sure that there can be one and only one
instance of a class e.g Window Manager,Print Spooler etc.

you can use a private constructor to prevent programmers
from creating instances of Singleton

Check out the following article:
http://www.dotnetextreme.com/code/SingletonCs.asp

Ravikanth[MVP]

-----Original Message-----
how do i prevent the second instance of my app from being instanced when oneis already running?
.

[Kieran Benton]

Ravikanth,

I think Shawn is trying to prevent a second instance of his "Program"
running. To do this it is common to obtain a exclusive lock on a file or
other shared resource when a program starts, and check to see if it is
possible (i.e. no other instance of the app has already obtained the lock).

Hope this helps,
Kieran

"Ravikanth[MVP]" <dv*********@ho tmail.com> wrote in message
news:0b******** *************** *****@phx.gbl.. .

Hi

Singleton assures that there is one and only one instance
of the class and provides a global point of access to
it.There are number of cases in programming where you
need to make sure that there can be one and only one
instance of a class e.g Window Manager,Print Spooler etc.

you can use a private constructor to prevent programmers
from creating instances of Singleton

Check out the following article:
http://www.dotnetextreme.com/code/SingletonCs.asp

Ravikanth[MVP]

-----Original Message-----
how do i prevent the second instance of my app from

being instanced when one

is already running?
.

[Jon Skeet]

Ravikanth[MVP] <dv*********@ho tmail.com> wrote:

Singleton assures that there is one and only one instance
of the class and provides a global point of access to
it.There are number of cases in programming where you
need to make sure that there can be one and only one
instance of a class e.g Window Manager,Print Spooler etc.

you can use a private constructor to prevent programmers
from creating instances of Singleton

Check out the following article:
http://www.dotnetextreme.com/code/SingletonCs.asp

Kieran has pointed out why this isn't actually useful in this case, but
I'd also like the say that the article you reference doesn't give a
thread-safe implementation of Singleton. There are much better ways of
implementing it.

See http://www.pobox.com/~skeet/csharp/singleton.html

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet/
If replying to the group, please do not mail me too