在C#中#if的用途是什么？

Question

我需要知道C#中#if的用法...谢谢..

Answer 1

#if是一个预处理器命令.

最常见的用法(有些人可能会说是滥用)是让代码只能在调试模式下编译:

#if DEBUG
    Console.WriteLine("Here");
#endif

一个非常好用(如StingyJack所指出的)是允许轻松调试Windows服务:

static void Main()
{
#if (!DEBUG)
    System.ServiceProcess.ServiceBase[] ServicesToRun;
    ServicesToRun = new System.ServiceProcess.ServiceBase[] { new Service1() };
    System.ServiceProcess.ServiceBase.Run(ServicesToRun);
#else
    // Debug code: this allows the process to run as a non-service.

    // It will kick off the service start point, but never kill it.

    // Shut down the debugger to exit

    Service1 service = new Service1();
    service.<Your Service's Primary Method Here>();
    // Put a breakpoint on the following line to always catch
    // your service when it has finished its work
    System.Threading.Thread.Sleep(System.Threading.Timeout.Infinite);
#endif 
}

资源

这意味着运行释放模式将按预期启动服务,而在调试模式下运行将允许您实际调试代码.