C#编程-82：编译预处理_

#define Debug
#define Release
#undef Debug
//#undef Release
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace DefineTest
{
    class Program
    {
        static void Main(string[] args)
        {
            #region 可以折叠
#if Debug && Release==false  
            Console.WriteLine("only debug");
#elif Debug &&Release
#error "不能同时出现debug和release"
            Console.WriteLine("debug and Release");
#elif (!Dubeg)&&Release
            Console.WriteLine("only release");
#else
            Console.WriteLine("no debug no release");
#endif
#if Release
            Console.WriteLine("release");
#endif
            #endregion
#line 200
#warning "这段话不能删除"
#warning "这段话不能删除"
#line default
#warning "这段话不能删除"
#warning "这段话不能删除"
#pragma warning disable
            int a = 9;
            int b = 13;
#pragma warning restore
            int[] my;
            Console.ReadKey();
        }
    }
}