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#IF DEBUG can be replaces with Conditional attribute

Pe un proiect legacy la care am lucrat anul acesta apareau destul de conditia urmatoare:
#if DEBUG
     //Some code
#endif
Natura proiectului ne obliga sa avem astfel de cod. Problema era ca uneori noi compilam proiectul configurat pentru RELEASE, faceam modificari la cod si in RELEASE totul parea in ordine, dar pe masina de build, aveam erori de compilare, deoarece acesta compila in DEBUG.
Am descoperit zilele acestea un nou atribut care poate sa inlocuiasca aceasta conditie urata.
[Conditional("DEBUG")]
public static void DoSomething()
{
     //Some code
}
Metoda DoSomething o sa fie apelata doar in cazul proiectul este compilat in DEBUG mode.
Cand putem sa folosim aceast atribut?
  • se poate folosi doar in interiorul unei clase sau a unei structuri. Nu incercati sa il puneti pe metoda unei interfete, deoarece o sa dea eroare la compilare
  • metoda pe care o decorati cu acest atribut nu trebuie sa fie neaparat statica, dar nu are voie sa fie implementarea  unei metode din interfata
  • metoda nu trebuie sa fie marcata cu override, dar poate sa contina atributul virtual
  • valoarea returnata de aceasta metoda trebuie obligatoriu sa fie void
Singurul lucru care poate sa  fie confusing este urmatorul cod:
public class Car
{
     public Car()
     {
          DoSomething();
     }     
     [Conditional("DEBUG")]
     public void DoSomething()
    {
          //Some code.
    }    
}
Ce o sa se intample la compilare daca avem setat RELEASE? O sa avem o eroare de compilare? Se va mai apela  metoda noastra? Raspunsul este ca codul general de IL nu va include si apelul la metoda DoSomething() daca compilam pentru RELEASE.
Personal incerc sa evit sa folosesc aceste conditii, nu sunt foarte sanatoase. Dar daca lucram deja pe un proiect care contine conditii de tip #if DEBUG, pentru a refactoriza codul si a scapa de aceste conditii, primul pas este sa le scoatem ca si metode separate, decorate cu atributul Conditional.

Comments

  1. Fain - asa e implementat si Debug.Assert, de ex..

    De conditional compilation in general nu prea ai cum sa scapi cand codul contine metode proprii de logging sau profiling care trebuie sa se execute doar la debug, nu si in release..

    ReplyDelete
  2. Drept. Dar macar le putem tine frumos grupate. Urasc sa dau de cod care contine atat logica cat si tot felu de conditii de compilare.

    ReplyDelete
  3. Adevarul e ca in C#, care nu are un preprocessor adevarat precum C++, genul asta de directive e mult mai rar folosit..

    ReplyDelete

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