Dispose called twice

[Sharon]

Hi.
I put a message box in the form designer, Dispose method.
Clicking the form close (X) button, i noticed that the message,
appears twice.
My code does not call Dispose.
What is happening here?
Thanks.
Sharon.

[Joe Mayo]

Hi Sharon,

You can add a boolean disposed member to your Form, initialized to false
(default). In Dispose, wrap your code in an if statement that checks
disposed to make sure it is false before doing anything. Then set disposed
to true.

Joe
--
http://www.csharp-station.com

"Sharon" <ta*******@void.null> wrote in message
news:OV**************@TK2MSFTNGP10.phx.gbl...

Hi.
I put a message box in the form designer, Dispose method.
Clicking the form close (X) button, i noticed that the message,
appears twice.
My code does not call Dispose.
What is happening here?
Thanks.
Sharon.

[yvinogradov]

Hi Sharon,

I don't know how your Dispose is implemented, but if it is not
synchronized by using the lock(this) statement doing so would help
ensure that the method is not called more than once from different
threads. Of course if you don't have a flag indicating whether the
method has been called or not you would need to add it as well.

Yan

[Jon Skeet [C# MVP]]

Telmo Sampaio <te***********@hotmail.com> wrote:

I do not know what is happening, however I can tell you you are not followig
the Dispose pattern correctly. The Dispose design pattern says that the
Dispose method can only be called once.

On the contrary - the Dispose design pattern specifically says that
IDisposable implementations should cope with Dispose being called
multiple times:

<quote>
If an object's Dispose method is called more than once, the object must
ignore all calls after the first one. The object must not throw an
exception if its Dispose method is called multiple times.
</quote>

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

[Sharon]

Thanks for your help.
I'll add the boolean field to my form.
And then i need to find out why is Dispose() called twice.
Sharon.

"Sharon" <ta*******@void.null> wrote in message
news:OV**************@TK2MSFTNGP10.phx.gbl...

Hi.
I put a message box in the form designer, Dispose method.
Clicking the form close (X) button, i noticed that the message,
appears twice.
My code does not call Dispose.
What is happening here?
Thanks.
Sharon.