c++ - 如何将字符串流中的数据打印到文件中？

Question

我使用 CreateFile fn 打开了一个文件，并尝试将数据打印到文件中。由于数据包含一些打印语句，例如

wprintf(L"找不到 channel %s。\n", pwsPath);

DATA和pwsPath的声明

#include <iostream>
#include <sstream>

using namespace std;
string data;
LPWSTR pwsPath = L"Channel1";

我尝试使用 stringstream 获取数据并将其转换为 LPCVOID 以使用 WriteFile fn，如图所示

hFile1 = CreateFile(L"MyFile.txt",                // name of the write
                   GENERIC_WRITE,          // open for writing
                   0,                      // do not share
                   NULL,                   // default security
                   CREATE_ALWAYS,             // create new file only
                   FILE_ATTRIBUTE_NORMAL,  // normal file
                   NULL); 

std::stringstream ss;
ss << "Channel" << pwsPath << "was not found.";

ss >> data;
cout << data; // data contains value only till the first space i.e Channel093902
cin>>data;



         bErrorFlag = WriteFile( 
                hFile1,           // open file handle
                data.c_str(),      // start of data to write
                dwBytesToWrite,  // number of bytes to write
                &dwBytesWritten, // number of bytes that were written
                NULL); 

变量 data 是否可以包含字符串流中的空格？？ 或者 除了 stringstream 之外，还有其他方法可以从此类打印语句中获取数据并写入文件吗？

Answer 1

>> 运算符会将流中的下一个“单词”传送到您提供的字符串对象中。正如您所发现的，它在第一个空白处中断。有几种方法可以实现您想要的。最符合要求的是将输出文件作为 ofstream 打开:

#include <iostream>
#include <sstream>
#include <fstream>

using namespace std;


int main()
{
    std::string pwsPath { "[enter path here]" };
    std::stringstream ss;
    ss << "Channel " << pwsPath << " was not found.";   

    std::ofstream outFile("myFile.txt");
    outFile << ss.rdbuf();
    outFile.close();

    std::ifstream inFile("myFile.txt");
    cout << inFile.rdbuf();

    return 0;
}

否则你可以从 ostringstream 中获取内部字符串:

std::string myData = ss.str();
size_t dataLength = myData.length();
DWORD dwBytesWritten = 0;
BOOL bErrorFlag = WriteFile( 
                hFile1,           // open file handle
                myData.data(),      // start of data to write
                DWORD(dataLength),  // number of bytes to write
                &dwBytesWritten, // number of bytes that were written
                NULL);