Exception Handling + Winforms

Ori,
Depending on the type of application you are creating, .NET has three
different global exception handlers.

For ASP.NET look at:
System.Web.HttpApplication.Error event
Normally placed in your Global.asax file.

For console applications look at:
System.AppDomain.UnhandledException event
Use AddHandler in your Sub Main.

For Windows Forms look at:
System.Windows.Forms.Application.ThreadException event
Use AddHandler in your Sub Main.

Hope this helps
Jay

"Ori" <or*******@hotmail.com> wrote in message
news:b4*************************@posting.google.co m...

Hi,

I would like to create some mechanism to handle all the exceptions
which will happen in my application.

I have one form which is the base form while all the other forms
inherit from it.

I try to find a way to "register" the base form to the Error handling
, but I don't know how..

Basically I'm try to catch an exceptions which occur in form2 (which
inherit from form1) through and exception handling which I will
implement through form1.

If any one has any idea, please let me know.

Thanks,

Ori.

Check out the Application.ThreadException
http://tinyurl.com/2upm9

Remarks
This event allows your Windows Forms application to handle otherwise
unhandled exceptions. Attach your event handlers to the ThreadException
event to deal with these exceptions, as these exceptions will leave your
application in an unknown state. Where possible, exceptions should be
handled by a structured exception handling block.
--
Greetz,
Jan
__________________________________
Read my weblog: http://weblogs.asp.net/jan

"Ori" <or*******@hotmail.com> schreef in bericht
news:b4*************************@posting.google.co m...

Hi,

I would like to create some mechanism to handle all the exceptions
which will happen in my application.

I have one form which is the base form while all the other forms
inherit from it.

I try to find a way to "register" the base form to the Error handling
, but I don't know how..

Basically I'm try to catch an exceptions which occur in form2 (which
inherit from form1) through and exception handling which I will
implement through form1.

If any one has any idea, please let me know.

Thanks,

Ori.

Hello Jay,

For console applications look at:
System.AppDomain.UnhandledException event
Use AddHandler in your Sub Main.
Is this event only for console applications? I thought it is raised despite
the type of the application (well, ASP .NET ones can be an exception). The
docs seem to say nothing about WinForms or console applications in the
"AppDomain.UnhandledException" topic.

--
Dmitriy Lapshin [C# / .NET MVP]
X-Unity Test Studio
http://x-unity.miik.com.ua/teststudio.aspx
Bring the power of unit testing to VS .NET IDE

"Jay B. Harlow [MVP - Outlook]" <Ja************@msn.com> wrote in message
news:%2****************@TK2MSFTNGP10.phx.gbl... Ori,
Depending on the type of application you are creating, .NET has three
different global exception handlers.

For ASP.NET look at:
System.Web.HttpApplication.Error event
Normally placed in your Global.asax file.

For console applications look at:
System.AppDomain.UnhandledException event
Use AddHandler in your Sub Main.

For Windows Forms look at:
System.Windows.Forms.Application.ThreadException event
Use AddHandler in your Sub Main.

Hope this helps
Jay

"Ori" <or*******@hotmail.com> wrote in message
news:b4*************************@posting.google.co m...

Hi,

I would like to create some mechanism to handle all the exceptions
which will happen in my application.

I have one form which is the base form while all the other forms
inherit from it.

I try to find a way to "register" the base form to the Error handling
, but I don't know how..

Basically I'm try to catch an exceptions which occur in form2 (which
inherit from form1) through and exception handling which I will
implement through form1.

If any one has any idea, please let me know.

Thanks,

Ori.

Dmitriy,
Yes its raised on all three, however it is the only one raised for console
applications, the other two are not.

My understanding of the event itself, which I admit is limited, its
usefulness in ASP.NET & Windows Form is "limited", hence my statement "for
console application". As I personally do not have a clear indication of when
you would need to include it in ASP.NET & Windows Forms, at least I cannot
really explain it. If you have something the clearly & briefly explains when
the event is raised, I would love to hear it.

Remember most unhandled exceptions in most Windows Forms apps will be
handled by the Application.ThreadException, the AppDomain.UnhandledException
will only handle the exceptions not handled by the above handler... (at
least that is my experience).

Hope this helps
Jay

"Dmitriy Lapshin [C# / .NET MVP]" <x-****@no-spam-please.hotpop.com> wrote
in message news:O9**************@TK2MSFTNGP11.phx.gbl...

Hello Jay,

For console applications look at:
System.AppDomain.UnhandledException event
Use AddHandler in your Sub Main.
Is this event only for console applications? I thought it is raised

despite the type of the application (well, ASP .NET ones can be an exception). The
docs seem to say nothing about WinForms or console applications in the
"AppDomain.UnhandledException" topic.

--
Dmitriy Lapshin [C# / .NET MVP]
X-Unity Test Studio
http://x-unity.miik.com.ua/teststudio.aspx
Bring the power of unit testing to VS .NET IDE

"Jay B. Harlow [MVP - Outlook]" <Ja************@msn.com> wrote in message
news:%2****************@TK2MSFTNGP10.phx.gbl...

Ori,
Depending on the type of application you are creating, .NET has three
different global exception handlers.

For ASP.NET look at:
System.Web.HttpApplication.Error event
Normally placed in your Global.asax file.

For console applications look at:
System.AppDomain.UnhandledException event
Use AddHandler in your Sub Main.

For Windows Forms look at:
System.Windows.Forms.Application.ThreadException event
Use AddHandler in your Sub Main.

Hope this helps
Jay

"Ori" <or*******@hotmail.com> wrote in message
news:b4*************************@posting.google.co m...

Hi,

I would like to create some mechanism to handle all the exceptions
which will happen in my application.

I have one form which is the base form while all the other forms
inherit from it.

I try to find a way to "register" the base form to the Error handling
, but I don't know how..

Basically I'm try to catch an exceptions which occur in form2 (which
inherit from form1) through and exception handling which I will
implement through form1.

If any one has any idea, please let me know.

Thanks,

Ori.

> Remember most unhandled exceptions in most Windows Forms apps will be

handled by the Application.ThreadException, the AppDomain.UnhandledException will only handle the exceptions not handled by the above handler... (at
least that is my experience).
Yes, I have bumped into something similar when working on a VS .NET add-in.
Strangely enough, the UnhandledException event didn't raise for the primary
thread the add-in was running on, while the event was raised as expected for
any other thread I had created manually. This came as a big and unpleasant
surprise, and I still haven't got any 'official' explanation. My only guess
is since VS .NET communicates with the add-in through CCW (COM-callable
wrappers), it is possible the framework silently installs its own handler
for the UnhandledException event to translate a managed exception to a COM
error (HRESULT + IErrorInfo).

As for the WinForms and ASP .NET applications, it is indeed better to use
the recommended means such as Application.ThreadException. Still, I'd add a
handler for UnhandledException too not to miss "survivors" who managed to
bypass the "first line of defense".

--
Dmitriy Lapshin [C# / .NET MVP]
X-Unity Test Studio
http://x-unity.miik.com.ua/teststudio.aspx
Bring the power of unit testing to VS .NET IDE

"Jay B. Harlow [MVP - Outlook]" <Ja************@msn.com> wrote in message
news:%2****************@TK2MSFTNGP12.phx.gbl... Dmitriy,
Yes its raised on all three, however it is the only one raised for console
applications, the other two are not.

My understanding of the event itself, which I admit is limited, its
usefulness in ASP.NET & Windows Form is "limited", hence my statement "for
console application". As I personally do not have a clear indication of when you would need to include it in ASP.NET & Windows Forms, at least I cannot
really explain it. If you have something the clearly & briefly explains when the event is raised, I would love to hear it.

Remember most unhandled exceptions in most Windows Forms apps will be
handled by the Application.ThreadException, the AppDomain.UnhandledException will only handle the exceptions not handled by the above handler... (at
least that is my experience).

Hope this helps
Jay

Dmitriy,

Still, I'd add a
handler for UnhandledException too not to miss "survivors" who managed to
bypass the "first line of defense". You won't get an argument for me, I was attempting the highlight just the
first line of defense, in an effort to "keep it simple".

When I use my exception snippet again I will try to incorporate our
discussion...

Thanks
Jay

"Dmitriy Lapshin [C# / .NET MVP]" <x-****@no-spam-please.hotpop.com> wrote
in message news:eS**************@TK2MSFTNGP11.phx.gbl...

Remember most unhandled exceptions in most Windows Forms apps will be
handled by the Application.ThreadException, the

AppDomain.UnhandledException

will only handle the exceptions not handled by the above handler... (at
least that is my experience).

Yes, I have bumped into something similar when working on a VS .NET

add-in. Strangely enough, the UnhandledException event didn't raise for the primary thread the add-in was running on, while the event was raised as expected for any other thread I had created manually. This came as a big and unpleasant
surprise, and I still haven't got any 'official' explanation. My only guess is since VS .NET communicates with the add-in through CCW (COM-callable
wrappers), it is possible the framework silently installs its own handler
for the UnhandledException event to translate a managed exception to a COM
error (HRESULT + IErrorInfo).

As for the WinForms and ASP .NET applications, it is indeed better to use
the recommended means such as Application.ThreadException. Still, I'd add a handler for UnhandledException too not to miss "survivors" who managed to
bypass the "first line of defense".

--
Dmitriy Lapshin [C# / .NET MVP]
X-Unity Test Studio
http://x-unity.miik.com.ua/teststudio.aspx
Bring the power of unit testing to VS .NET IDE

"Jay B. Harlow [MVP - Outlook]" <Ja************@msn.com> wrote in message
news:%2****************@TK2MSFTNGP12.phx.gbl...

Dmitriy,
Yes its raised on all three, however it is the only one raised for console applications, the other two are not.

My understanding of the event itself, which I admit is limited, its
usefulness in ASP.NET & Windows Form is "limited", hence my statement "for console application". As I personally do not have a clear indication of

when

you would need to include it in ASP.NET & Windows Forms, at least I cannot really explain it. If you have something the clearly & briefly explains

when

the event is raised, I would love to hear it.

Remember most unhandled exceptions in most Windows Forms apps will be
handled by the Application.ThreadException, the

AppDomain.UnhandledException

will only handle the exceptions not handled by the above handler... (at
least that is my experience).

Hope this helps
Jay

Jay,

I didn't mean to argue either, my sole intention was to warn you and the
community that peculiar things with UnhandledException could happen and they
were undocumented.

--
Dmitriy Lapshin [C# / .NET MVP]
X-Unity Test Studio
http://x-unity.miik.com.ua/teststudio.aspx
Bring the power of unit testing to VS .NET IDE

"Jay B. Harlow [MVP - Outlook]" <Ja************@msn.com> wrote in message
news:uU**************@tk2msftngp13.phx.gbl...

Dmitriy,

Still, I'd add a
handler for UnhandledException too not to miss "survivors" who managed to

bypass the "first line of defense". You won't get an argument for me, I was attempting the highlight just the
first line of defense, in an effort to "keep it simple".

When I use my exception snippet again I will try to incorporate our
discussion...

Thanks
Jay

"Dmitriy Lapshin [C# / .NET MVP]" <x-****@no-spam-please.hotpop.com> wrote
in message news:eS**************@TK2MSFTNGP11.phx.gbl... Remember most unhandled exceptions in most Windows Forms apps will be
handled by the Application.ThreadException, the

AppDomain.UnhandledException

will only handle the exceptions not handled by the above handler... (at least that is my experience).

Yes, I have bumped into something similar when working on a VS .NET

add-in.

Strangely enough, the UnhandledException event didn't raise for the

primary

thread the add-in was running on, while the event was raised as expected

for

any other thread I had created manually. This came as a big and unpleasant

surprise, and I still haven't got any 'official' explanation. My only

guess

is since VS .NET communicates with the add-in through CCW (COM-callable
wrappers), it is possible the framework silently installs its own handler for the UnhandledException event to translate a managed exception to a COM error (HRESULT + IErrorInfo).

As for the WinForms and ASP .NET applications, it is indeed better to use the recommended means such as Application.ThreadException. Still, I'd add a

handler for UnhandledException too not to miss "survivors" who managed

to bypass the "first line of defense".

--
Dmitriy Lapshin [C# / .NET MVP]
X-Unity Test Studio
http://x-unity.miik.com.ua/teststudio.aspx
Bring the power of unit testing to VS .NET IDE

"Jay B. Harlow [MVP - Outlook]" <Ja************@msn.com> wrote in message news:%2****************@TK2MSFTNGP12.phx.gbl...

Dmitriy,
Yes its raised on all three, however it is the only one raised for console applications, the other two are not.

My understanding of the event itself, which I admit is limited, its
usefulness in ASP.NET & Windows Form is "limited", hence my statement "for console application". As I personally do not have a clear indication of when

you would need to include it in ASP.NET & Windows Forms, at least I cannot really explain it. If you have something the clearly & briefly

explains when

the event is raised, I would love to hear it.

Remember most unhandled exceptions in most Windows Forms apps will be
handled by the Application.ThreadException, the

AppDomain.UnhandledException

will only handle the exceptions not handled by the above handler...

(at least that is my experience).

Hope this helps
Jay