CODEWITHSUNDEEP
c#try-catch
Ozkan
Ozkan

Reputation: 4160

Skip finally in a specific catch

Let's say I have to catch 3 different exceptions, so I write 3 separate catch blocks. But I want to skip the finally block for one specific exception.

As far as I know this is not possible using a builtin flag. But can you advise how to solve this coding problem in elegant way?

When not using finally, I have to rewrite the same code several times, in try and also in other catch blocks.

More information: In finally I let the thread sleep for some time (await Task.Delay(5 * 1000);) But if I receive a OperationCanceledExceptionthen I don't want the finally to be run. I want it to break as fast as possible.

while (true)
{
    try
    {
        _cts.Token.ThrowIfCancellationRequested();
    }
    catch (OperationCanceledException)
    {
        break;
    }
    catch (CustomException1 e)
    {

    }
    catch (CustomException2 e)
    {

    }                
    finally
    {
        await Task.Delay(5 * 1000);
    }
}

Upvotes: 7

Views: 3669

Answers (2)

MakePeaceGreatAgain
MakePeaceGreatAgain

Reputation: 37000

Seems like you could use an exception-filter to filter all exceptions that should have some tidy-up-code and one single exception that doesn´t.

try
{
    DoSomething();
}
catch(Exception e) when (e is MyException || e is AnotherException)
{
    // your error-handling
    // ...
    await Task.Delay(5 * 1000);
}
catch(SpecificExceptionWithoutFinally e)
{
    ...
}

Before C#6 you could also introduce some flag indicating if the code should be executed:

var executeFinally = false;

try
{
    DoSomething();
}
catch(MyException e) 
{
    executeFinally = true;
}
catch(AnotherExceptione)
{
    executeFinally = true;
}    
catch(SpecificExceptionWithoutFinally e)
{
    ...
}
finally
{
    if(executeFinally) {
        await Task.Delay(5 * 1000);
    }
}

Anyway, this seems like a weird requirement, as the whole point of a finally is to be guaranteed to always run regardless on any exception being thrown.

Upvotes: 2

FortyTwo
FortyTwo

Reputation: 2639

Do nothing in the finally block if nothing is to be done

bool skipFinallyFlag = false;
try
{
    //My stuff
}
catch(Exception1 ex1)
{
    //Do something
}
catch(Exception2 ex2)
{
    //Do something
}
catch(Exception3 ex3)
{
    skipFinallyFlag = true;     
}
finally
{
    if(!skipFinallyFlag)
    {
        //Do something
    }
}

Upvotes: 12

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