c ++:ifstream打开传递文本文件名的字符串的问题 [英] c++: ifstream open problem with passing a string for text file name
问题描述
我试图传递一个字符串从main到另一个函数。此字符串是需要打开的文本文件的名称。只要我可以看到,我传递字符串alright,但当我尝试使用 ifstream.open(textFileName)
,它不工作。但是当我手动硬编码为 ifstream.open(foo.txt)
,它工作正常。我需要使用这个函数几次,所以我想能够传递一个文本文件名的字符串..
i'm trying to pass a string from main to another function. this string is a name of text file that needs to be oepened. as far as i can see, i am passing the string alright, but when i try to use ifstream.open(textFileName)
, it doesn't quite work. but when i manually hardcode it as ifstream.open("foo.txt")
, it works just fine. i would need to use this function several times so i would like to be able to pass in a string of text file name..
这里是我的主
#ifndef DATA_H
#define DATA_H
#include "Data.h"
#endif
#ifndef DATAREADER_H
#define DATAREADER_H
#include "DataReader.h"
#endif
using namespace std;
int main()
{
vector<Data*> database = DataReader("foo.txt");
return 0;
}
DataReader的标题
header of DataReader
#include <fstream>
#include <iostream>
#include <vector>
#include <string>
#ifndef DATA_H
#define DATA_H
#include "Data.h"
#endif
using namespace std;
vector<Data*> DataReader(string textFile);
,最后是DataReader.cpp
and finally the DataReader.cpp
#include "DataReader.h"
using namespace std;
vector<Data*> DataReader(string textFile)
{
ifstream aStream;
aStream.open(textFile); //line 11
我查找了ifstream.open(),它需要一个字符串和模式作为参数。不太确定如何处理模式,但我尝试过,但他们给了相同的错误消息
i looked up the ifstream.open() and it takes a string and a mode as parameters. not really sure what to do with the modes, but i tried them but they gave the same error message
DataReader.cpp: In function 'std::vector<Data*, std::allocator<Data*> > DataReader(std::string)':
DataReader.cpp:11: error: no matching function for call to 'std::basic_ifstream<char, std::char_traits<char> >::open(std::string&)'
/usr/local/lib/gcc/sparc-sun-solaris2.9/4.0.3/../../../../include/c++/4.0.3/fstream:495: note: candidates are: void std::basic_ifstream<_CharT, _Traits>::open(const char*, std::_Ios_Openmode) [with _CharT = char, _Traits = std::char_traits<char>]
预先感谢您提供任何意见或建议。
thank you in advance for any input/suggestions.
Dean
推荐答案
标准流不接受标准字符串
,只有 c-string
!因此,使用 c_str()
:
the standard streams doesn't accept a standard string
, only c-string
! So pass the string using c_str()
:
aStream.open(textFile.c_str());
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