C#中的预处理器指令 [英] Preprocessor directives in C#

问题描述

在C#中，如果预处理程序指令是在实际编译之前进行预处理的指令，那么为什么不在该程序中首先执行该指令?

In C#, if preprocessor directives are instructions pre-processed before actual compilation then why is it not executed first in this program?

static void Main(string[] args)
        {
            Program1.display();
            Program2 p2 = new Program2();
            p2.show();
#if DEBUG
Console.WriteLine("DEBUG from preprocessor directive is working!");
#endif
        }

预期输出:

DEBUG from preprocessor directive is working!
.......(from display())
.......(from show())

但实际输出:

.......(from display())
.......(from show())
DEBUG from preprocessor directive is working!

推荐答案

您期望的输出是错误的.

The output you are expecting is wrong.

在 DEBUG 模式/配置下处理(待编译)的代码

Code processed (to be compiled) in DEBUG mode/configuration

static void Main(string[] args)
{
    Program1.display();
    Program2 p2 = new Program2();
    p2.show();
    Console.WriteLine("DEBUG from preprocessor directive is working!");
}

以非- DEBUG 模式/配置处理(待编译)的代码

Code processed (to be compiled) in non-DEBUG mode/configuration

static void Main(string[] args)
{
    Program1.display();
    Program2 p2 = new Program2();
    p2.show();
}

希望这可以消除您的困惑，即预处理器不会决定执行顺序.

Hope this clears your confusion that preprocessors don't decide execution order.

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