troubles with finally statement and objects

[Chris]

Hi,

I am using the try catch finally block in many places in my code.

When a create an sqldatareader dr and try to close it in my
finally block I get the error: use of unsigned local variable.

dr.close();
works fine in the try but not in the finally.

How can I access my local objects in the finally without these errors?

thanks

Chris

[Cor Ligthert [MVP]]

Chris,

You can set a try block nested which is very nice for this kind of
operations.

try{open whatever;
try{}catch{}
}
catch{}
finally{close whatever;}

I hope this helps,

Cor

[Chris]

Thanks Everyone for your responses.

I am having trouble finding the namespace that provides me with the
command: CommandBehavior .CloseConnectio n.

I'm getting the type or namespace missing error.
Could someone direct me how get it up and running. I have a hunch it's not
really
my namespace missing but a scope issue?

thanks

chris

"Chris" wrote:

Hi,

I am using the try catch finally block in many places in my code.

When a create an sqldatareader dr and try to close it in my
finally block I get the error: use of unsigned local variable.

dr.close();
works fine in the try but not in the finally.

How can I access my local objects in the finally without these errors?

thanks

Chris

[Jon Skeet [C# MVP]]

Chris <Ch***@discussi ons.microsoft.c om> wrote:

Thanks Everyone for your responses.

I am having trouble finding the namespace that provides me with the
command: CommandBehavior .CloseConnectio n.

I'm getting the type or namespace missing error.
Could someone direct me how get it up and running. I have a hunch it's not
really my namespace missing but a scope issue?

CommandBehavior is an enumeration in the System.Data namespace.

If that doesn't help, perhaps you could give an example of how you're
trying to use it?

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

[Chris Dunaway]

Jon wrote:

using (SqlDataReader data = command.Execute Reader
(CommandBehavio r.CloseConnecti on))

What would happen if the ExecuteReader command returned null? Does the
using construct check for null before it calls .Dispose?

[Scott Roberts]

"Chris Dunaway" <du******@gmail .com> wrote in message
news:11******** **************@ z14g2000cwz.goo glegroups.com.. .

Jon wrote:

using (SqlDataReader data = command.Execute Reader
(CommandBehavio r.CloseConnecti on))
What would happen if the ExecuteReader command returned null?

I don't see "null" listed as a possible return value.
Does the
using construct check for null before it calls .Dispose?

In general, I would expect to get an exception if the "using" statement was
executed on "null".

[Jon Skeet [C# MVP]]

Chris Dunaway <du******@gmail .com> wrote:

Jon wrote:

using (SqlDataReader data = command.Execute Reader
(CommandBehavio r.CloseConnecti on))

What would happen if the ExecuteReader command returned null? Does the
using construct check for null before it calls .Dispose?

Yes. From the C# spec (reformatted with sane bracing):

<quote>
A using statement of the form

using (R r1 = new R())
{
r1.F();
}

is precisely equivalent to

R r1 = new R();
try
{
r1.F();
}
finally
{
if (r1 != null) ((IDisposable)r 1).Dispose();
}
</quote>

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

[Jon Skeet [C# MVP]]

Scott Roberts <sc***********@ no-spam.intelebill .com> wrote:

Does the
using construct check for null before it calls .Dispose?

In general, I would expect to get an exception if the "using" statement was
executed on "null".

No - you won't get an exception unless the body of the using statement
tries to dereference the null value.

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