#if !defined(AFX_DLGWTCD_H__F639CF88_AE44_4750_9675_A539D7471AA3__INCLUDED_)
#define AFX_DLGWTCD_H__F639CF88_AE44_4750_9675_A539D7471AA3__INCLUDED_#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
#define AFX_DLGWTCD_H__F639CF88_AE44_4750_9675_A539D7471AA3__INCLUDED_#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
#pragma once 判断操作系统的版本
#endif // _MSC_VER > 1000
关于
#pragma once:
Specifies that the file, in which the pragma resides, will be included (opened) only once by the compiler in a build. A common use for this pragma is the following:
#define AFX_DLGWTCD_H__F639CF88_AE44_4750_9675_A539D7471AA3__INCLUDED_这个避免重复定义的预编译语句。#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000如果版本大于1000只编译一次。
#pragma once
// Your C or C++ code would follow: