为啥我不能将字符串传递给函数 GetDriveTypesA()？

Posted 2023-02-22

【中文标题】为啥我不能将字符串传递给函数 GetDriveTypesA()？

【英文标题】：Why can't I pass a string into the function GetDriveTypesA()?为什么我不能将字符串传递给函数 GetDriveTypesA()？

【发布时间】：2019-03-13 22:25:13

【问题描述】：

因此，该计划的目的是找出可用的驱动器以及它们是什么。但是，我似乎无法将字符串变量直接传递给GetDriveTypesA()。但是，如果我只是做GetDriveTypesA("C:\\")，它就会成功。

请有人帮我找到解决这个问题的方法，程序如下。谢谢你:)

#include <iostream>
#include <windows.h>
#include <string>

using namespace std;

int main() 
    int i;
    int driveType;
    std::string path;
    int binary[26] = 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0; //To save the binary number of the GetLogicalDrives
    std::string  actualDrives[26];
    std::string letters[26] = "A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"; //letters of the alphabet
    DWORD drives = GetLogicalDrives(); //finds the bit mask of logical drives

    for(i=0; drives>0; i++)  //changes the integer into a binary number
        binary[i]=drives%2;
        drives= drives/2;
    
    for (i=0; i<26; i++) //finds out what drive letters are available
        if (binary[i]==1)
            actualDrives[i] = letters[i];
        
    
    for (i=0; i<26; i++) \trying to find the drive type
        if (actualDrives[i] != "")
        cout << "Actual drive:";
        cout<< actualDrives[i] <<endl;
        path = actualDrives[i] + ":\\";
        cout << path <<endl;
        driveType = GetDriveTypeA(path); //the part of the code that does not work but does work if a string is just entered
        cout<< driveType << endl;
        
    

【问题讨论】：

您的编译器对此有何评论？

改用 path.data()。

【参考方案1】：

因为GetDriveTypeA() 采用C string，而不是C++ std::string。

UINT GetDriveTypeA(
  LPCSTR lpRootPathName
);

使用std::string.c_str() 方法：

driveType = GetDriveTypeA(path.c_str());