Catching exceptions when calling a WebServices method asynchronously

[John Skandar]

I've found a free WebService on the net for a currency converter and have
created a class to use it with the WSDL tool.

I call the WebService method asynchronously:

converter.Conve rsionRateAsync( (Currency)fromC urrencyComboBox .SelectedIndex,
(Currency)toCur rencyComboBox.S electedIndex);

Where do I have to put the catch instruction?
If I try to run the instruction above when I am not connected to the
Internet, I receive a message with a System.Net.WebE xception exception.
Where can I catch it?

Thanks
----
Dr. John Skandar
<yugo_amaryl@ms n.com>

[Mr. Arnold]

Re: Catching exceptions when calling a WebServices method asynchronously


"John Skandar" <yugo_amaryl@ms n.comwrote in message
news:15F99297-7A0D-44FF-BCFB-0496E590427A@mi crosoft.com...

I've found a free WebService on the net for a currency converter and have
created a class to use it with the WSDL tool.
>
I call the WebService method asynchronously:

Try
{
converter.Conve rsionRateAsync( (Currency)fromC urrencyComboBox .SelectedIndex,
(Currency)toCur rencyComboBox.S electedIndex);
}
catch(Excption ex)
{
message
}

>
Where do I have to put the catch instruction?
If I try to run the instruction above when I am not connected to the
Internet, I receive a message with a System.Net.WebE xception exception.
Where can I catch it?
>
Thanks
----
Dr. John Skandar
<yugo_amaryl@ms n.com>

[John Skandar]

Re: Catching exceptions when calling a WebServices method asynchronously

Ehm... maybe if it had been so simple I wouldn't have asked...

The problem is that the exception is not thrown by the method itself,
because the asynchronous call just starts the operation, that is performed
by another thread while the program continues performing its tasks. I need
to know how to catch an exception that is thrown in that thread.

"Mr. Arnold" <MR. Arnold@Arnold.c omha scritto nel messaggio
news:#TMC0FY9IH A.3344@TK2MSFTN GP02.phx.gbl...

>
"John Skandar" <yugo_amaryl@ms n.comwrote in message
news:15F99297-7A0D-44FF-BCFB-0496E590427A@mi crosoft.com...

>I've found a free WebService on the net for a currency converter and have
>created a class to use it with the WSDL tool.
>>
>I call the WebService method asynchronously:

>
>
>
Try
{
>
converter.Conve rsionRateAsync( (Currency)fromC urrencyComboBox .SelectedIndex,
(Currency)toCur rencyComboBox.S electedIndex);
}
catch(Excption ex)
{
message
}
>

>>
>Where do I have to put the catch instruction?
>If I try to run the instruction above when I am not connected to the
>Internet, I receive a message with a System.Net.WebE xception exception.
>Where can I catch it?
>>
>Thanks
>----
>Dr. John Skandar
><yugo_amaryl@m sn.com>

>
>

[Chicken Little Albright]

Re: Catching exceptions when calling a WebServices method asynchronously

John Skandar wrote:

Ehm... maybe if it had been so simple I wouldn't have asked...
>
The problem is that the exception is not thrown by the method itself,
because the asynchronous call just starts the operation, that is
performed by another thread while the program continues performing its
tasks. I need to know how to catch an exception that is thrown in that
thread.

Well, if possible, the Web service needs to return some return codes on
success or when an exception failure has be thrown by the Web service on
an asynchronous call to the Web service that the client can check. It's
not going to be business as usual as in a synchronous call to Web
service is made by a client.

<http://it.toolbox.com/blogs/distributed-systems/errors-exceptions-and-asynchronous-web-services-15328>