Debug conditional code in class that implements an interface... does it work?

[hellosticky]

I'm creating some logging code, and each one of my classes has an
internal static readonly instance of the logger which various methods
use, e.g.:

interface ILogger
{
void LogDebug(...);
void LogInfo(...);
void LogError(...);
...
}

What I did was to create two classes, one in the case where the Logger
for that class is off, and the other when it is on.

class Logger : ILogger {...}

class NullLogger : ILogger {
[Conditional("DEBUG")]
public void LogDebug(...)
{
}
....
}

Now, my question is, the ILogger instance is assigned at runtime. So,
if I assign the NullLogger at runtime, which has [Conditional("DEBUG")]
will it still for sure not evaluate the parameters passed to the Log
method if it is of type NullLogger?

For example, with Conditional("DEBUG"), the executeLongMethodToGetValue
is not executed.

myLog.LogDebug(myObj.executeLongMethodToGetValue())

In this case, myLog is an interface assigned at runtime. If it is of
type NullLogger, will this still not evaluate
executeLongMethodToGetValue?

Thanks!

 

[Mattias Sjögren]

Now, my question is, the ILogger instance is assigned at runtime. So,
if I assign the NullLogger at runtime, which has [Conditional("DEBUG")]
will it still for sure not evaluate the parameters passed to the Log
method if it is of type NullLogger?

No it will evaluate the parameters. The ConditionalAttribute is a
compile-time feature.

Your code shouldn't even compile. Conditional method are not allowed
to implement interface members.


Mattias