_MSC_VER 定义了编译器版本。
#pragma once
Specifies that the file, in which the pragma resides, will be included (opened) only once by the compiler in a build.
#pragma once
Specifies that the file, in which the pragma resides, will be included (opened) only once by the compiler in a build.
定义的文件只包含1次。
VC版本和_MSC_VER定义有一定的规律:
VC6 1200
VC5 1100
VC4.2 1020
VC4 1000
VC2 900(没有VC3)
......
VC5 1100
VC4.2 1020
VC4 1000
VC2 900
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
又都是什么意思,多谢