你如何用C ++打开文件？ [英] How do you open a file in C++?

问题描述

我想打开一个用于阅读的文件，即C ++方式。我需要能够做到：

I want to open a file for reading, the C++ way. I need to be able to do it for:

• 文本文件，这将涉及某种读取线功能。

• text files, which would involve some sort of read line function.

二进制文件，它提供了一种将原始数据读入 char * 缓冲区的方法。

binary files, which would provide a way to read raw data into a char* buffer.

推荐答案

根据您的需要，有三种方法可以做到这一点。您可以使用旧式C语言并调用fopen / fread / fclose，或者您可以使用C ++ fstream工具（ifstream / ofstream），或者如果您使用的是MFC，请使用CFile类，它提供了实现实际的功能文件操作。

There are three ways to do this, depending on your needs. You could use the old-school C way and call fopen/fread/fclose, or you could use the C++ fstream facilities (ifstream/ofstream), or if you're using MFC, use the CFile class, which provides functions to accomplish actual file operations.

所有这些都适用于文本和二进制文件，但没有一个具有特定的readline功能。在这种情况下你最有可能做的是使用fstream类（fstream.h）并使用流操作符（<<和>>）或read函数来读/写文本块：

All of these are suitable for both text and binary, though none have a specific readline functionality. What you'd most likely do instead in that case is use the fstream classes (fstream.h) and use the stream operators (<< and >>) or the read function to read/write blocks of text:

int nsize = 10;
char *somedata;
ifstream myfile;
myfile.open("<path to file>");
myfile.read(somedata,nsize);
myfile.close();

请注意，如果您使用的是Visual Studio 2005或更高版本，则可能无法使用传统的fstream（有一个新的Microsoft实现，略有不同，但完成相同的事情。）

Note that, if you're using Visual Studio 2005 or higher, traditional fstream may not be available (there's a new Microsoft implementation, which is slightly different, but accomplishes the same thing).

这篇关于你如何用C ++打开文件？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！