C#.NET学习笔记5 C#中的条件编译

#define Debug
  class Class1
 {
      #if Debug
      void Trace(string s) {}
      #endif
 }

class Class1
{
   void Trace(string s) {}
}

#define A
   #define B
   #undef C
   class D
  {
      #if C
         void F() {}
             #elif A && B
                void I() {}
      #else
         void G() {}
      #endif
  }

class C
{
   void I() {}
}

#define Debug // Debugging on
   #undef Trace // Tracing off
   class PurchaseTransaction
  {
      void Commit()
    {
      #if Debug
          CheckConsistency();
          #if Trace
            WriteToLog(this.ToString());
          #endif
      #endif
      CommitHelper();
     }
  }

#define DEBUG
   #define RELEASE
   #define DEMO VERSION
     #if DEMO VERSION && !DEBUG
        #warning you are building a demo version
     #endif
     #if DEBUG && DEMO VERSION
       #error you cannot build a debug demo version
     #endif
   using System;
   class Demo
  {
     public static void Main()
    {
      Console.WriteLine(“Demo application”);
    }
  }