Empty catch

[DaTurk]

What's the CLI equivalent of the empty catch?

i.e.
try{}
catch
{}

[William DePalo [MVP VC++]]

"DaTurk" <mm******@hotmail.comwrote in message
news:11**********************@y2g2000prf.googlegro ups.com...

What's the CLI equivalent of the empty catch?

i.e.
try{}
catch
{}

How about this:

try
{
Console::WriteLine(L"Hello World");
}

catch ( Exception^ )
{
}

Regards,
Will

[=?Utf-8?B?RGF2aWQgQW50b24=?=]

try
{
}
catch(...)
{
}

--
David Anton
www.tangiblesoftwaresolutions.com
Instant C#: VB to C# converter
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"DaTurk" wrote:

What's the CLI equivalent of the empty catch?

i.e.
try{}
catch
{}

[SvenC]

DaTurk wrote:

What's the CLI equivalent of the empty catch?

i.e.
try{}
catch
{}

Where is that empty catch allowed? It is not standard C++. Do you mean
catch(...) ?

--
SvenC

[Carl Daniel [VC++ MVP]]

"SvenC" <Sv***@community.nospamwrote in message
news:e4**************@TK2MSFTNGP03.phx.gbl...

DaTurk wrote:

>What's the CLI equivalent of the empty catch?

i.e.
try{}
catch
{}

Where is that empty catch allowed? It is not standard C++. Do you mean
catch(...) ?

It's allowed in C#. It's equivalent to the C++/CLI construct:

try
{
}
catch(Exception^)
{
}

Using catch(...) will also catch native exceptions, and possibly structured
(platform) exceptions, depending on the compiler options used.

-cd

[DaTurk]

On May 22, 12:39 am, "SvenC" <[e-mail]:

DaTurk wrote:

What's the CLI equivalent of the empty catch?

i.e.
try{}
catch
{}

Where is that empty catch allowed? It is not standard C++. Do you mean
catch(...) ?

--
SvenC

My apologies, I was refering to c#

[Jochen Kalmbach [MVP]]

Hi Carl!

>>>What's the CLI equivalent of the empty catch?

i.e.
try{}
catch
{}

It's allowed in C#. It's equivalent to the C++/CLI construct:

try
{
}
catch(Exception^)
{
}

No. "catch(Exception^)" is *not* the same as "catch" in C#!

"catch(Exception^)" will *only* catch exceptions which are derived from
"System.Exception"!

"catch" will catch *all* Exceptions (derived from "System.Object")!
It also will catch native exceptins in C#!!!
Therefor the C++/CLI equivalent of "catch" is "catch(System::Object^)" !

See also: Basic Concepts in Using Managed Exceptions
http://msdn2.microsoft.com/en-us/lib...b6(VS.80).aspx
--
Greetings
Jochen

My blog about Win32 and .NET
http://blog.kalmbachnet.de/

[Jochen Kalmbach [MVP]]

DaTurk schrieb:

What's the CLI equivalent of the empty catch?

i.e.
try{}
catch
{}

try {}
catch(System::Object^)
{}

--
Greetings
Jochen

My blog about Win32 and .NET
http://blog.kalmbachnet.de/

[Carl Daniel [VC++ MVP]]

"Jochen Kalmbach [MVP]" <no********************@holzma.dewrote in message
news:%2****************@TK2MSFTNGP05.phx.gbl...

Hi Carl!

>>>>What's the CLI equivalent of the empty catch?

i.e.
try{}
catch
{}

It's allowed in C#. It's equivalent to the C++/CLI construct:

try
{
}
catch(Exception^)
{
}

No. "catch(Exception^)" is *not* the same as "catch" in C#!

"catch(Exception^)" will *only* catch exceptions which are derived from
"System.Exception"!

"catch" will catch *all* Exceptions (derived from "System.Object")!
It also will catch native exceptins in C#!!!

Egads!

I'd forgotten that the CLR actually supporting throwing something not
derived from System.Exception!

-cd

[Ben Voigt]

It also will catch native exceptins in C#!!!

Wouldn't catch (Exception^) do so as well, giving an SEHException? Or is
that only for p/invoke?

[Jochen Kalmbach [MVP]]

Hi Ben!

>It also will catch native exceptins in C#!!!

Wouldn't catch (Exception^) do so as well, giving an SEHException? Or is
that only for p/invoke?

SEHException is also derived from "System.Exception". But you can throw
*any* object as an exception. Therefor, if you want to catch *all*
exceptions, you need to catch "System.Object" instead of "System.Exception"!

See:

#pragma unmanaged

void Test1()
{
throw 1;
}

#pragma managed

void Test2()
{
throw 2;
}

void Test3()
{
throw gcnew System::Object();
}

int main()
{
try
{
Test1();
}
catch(System::Object ^o)
{
System::Console::WriteLine("Test1: " + o->GetType()->ToString());
}

try
{
Test2();
}
catch(System::Object ^o)
{
System::Console::WriteLine("Test2: " + o->GetType()->ToString());
}

try
{
Test3();
}
catch(System::Object ^o)
{
System::Console::WriteLine("Test3: " + o->GetType()->ToString());
}
}
Output is:
Test1: System.Runtime.InteropServices.SEHException
Test2: System.Runtime.InteropServices.SEHException
Test3: System.Object

Greetings
Jochen

[Ben Voigt]

"Jochen Kalmbach [MVP]" <no********************@holzma.dewrote in message
news:en**************@TK2MSFTNGP06.phx.gbl...

Hi Ben!

>>It also will catch native exceptins in C#!!!

Wouldn't catch (Exception^) do so as well, giving an SEHException? Or is
that only for p/invoke?

SEHException is also derived from "System.Exception". But you can throw
*any* object as an exception. Therefor, if you want to catch *all*
exceptions, you need to catch "System.Object" instead of
"System.Exception"!

See:

I wasn't doubting that catching System.Object will catch all exceptions...
but wouldn't catching System.Exception also catch all exceptions, decoding
managed objects derived from Exception, and wrapping everything else in
SEHException?

>
#pragma unmanaged

void Test1()
{
throw 1;
}

#pragma managed

void Test2()
{
throw 2;
}

void Test3()
{
throw gcnew System::Object();
}

int main()
{
try
{
Test1();
}
catch(System::Object ^o)
{
System::Console::WriteLine("Test1: " + o->GetType()->ToString());
}

try
{
Test2();
}
catch(System::Object ^o)
{
System::Console::WriteLine("Test2: " + o->GetType()->ToString());
}

try
{
Test3();
}
catch(System::Object ^o)
{
System::Console::WriteLine("Test3: " + o->GetType()->ToString());
}
}
Output is:
Test1: System.Runtime.InteropServices.SEHException
Test2: System.Runtime.InteropServices.SEHException
Test3: System.Object

Greetings
Jochen

[Jochen Kalmbach [MVP]]

Hi Ben!

I wasn't doubting that catching System.Object will catch all exceptions...
but wouldn't catching System.Exception also catch all exceptions, decoding
managed objects derived from Exception, and wrapping everything else in
SEHException?

I don't understand the background of this question?

I don't know the internals of every assembly; so I don't know if
"System.Exception" will catch *all* exceptions... regardless of
SEHException...

Greetings
Jochen

[Mattias Sjögren]

>I wasn't doubting that catching System.Object will catch all exceptions...

>but wouldn't catching System.Exception also catch all exceptions, decoding
managed objects derived from Exception, and wrapping everything else in
SEHException?

I don't understand the background of this question?

I don't know the internals of every assembly; so I don't know if
"System.Exception" will catch *all* exceptions... regardless of
SEHException...

You can also use the RuntimeCompatibilityAttribute on your assembly
with WrapNonExceptionThrows = true to make sure all exceptions you see
are derived from Exception (if they aren't already, they get wrapped
in a RuntimeWrappedException). That's what C# does for example.
Mattias

--
Mattias Sjögren [C# MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
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