为什么 PathFileExists() 不起作用? [英] Why PathFileExists() not working?

问题描述

我想验证文件是否存在，经过一些搜索，我认为 PathFileExists() 可能适合该工作.但是，以下代码始终显示该文件不存在.为了确保文件确实存在，我选择cmd.exe的完整路径作为测试文件路径.我使用的是 Windows 7 (x64)

I want to validate the existence of a file and after some search I think PathFileExists() may fit the job. However, the following code always show the file doesn't exist. To ensure the file really exist, I choose full path of cmd.exe as the test file path. I'm using windows 7 (x64)

#include "stdafx.h" 
#include <stdio.h>
#include <windows.h>
#include <shlwapi.h>
#include <WinDef.h>
#pragma comment( lib, "shlwapi.lib")

int _tmain(int argc, _TCHAR* argv[])
{ 

    char path[] = "c:\\Windows\\System32\\cmd.exe";
    LPCTSTR szPath = (LPCTSTR)path;
    if(!PathFileExists(szPath)) 
    { 
        printf("not exist\n");  
    }else{
        printf("exists!\n"); 
    }
    return 0; 
} 

你能解释一下这个问题吗?

Can you explain about the problem?

花了几乎整个下午的时间来找出问题所在.PathFileExists() 函数需要 LPCTSTR 类型的第二个参数.但是，编译器无法将 char * 正确转换为 LPCTSTR 然后我包含 tchar.h 并使用 TEXT 宏来初始化指针.完毕.LPCTSTR lpPath = TEXT("c:\Windows\System32\cmd.exe");PathFileExists 的 MSDN 参考示例代码() 有点过时了.参考示例直接将 char * 用于 PathFileExists() 并且无法在 Visual Studio 2011 beta 中通过编译.而且，示例代码错过了 using namespace std;其中，我认为@steveha 的答案最接近真正的问题.谢谢大家.

Spend almost whole afternoon and figure out the problem. The PathFileExists() function expect second parameter of type LPCTSTR.However, the compiler can not correctly convert char * to LPCTSTR then I include tchar.h and using the TEXTmacro to initialize the pointer. Done. LPCTSTR lpPath = TEXT("c:\Windows\System32\cmd.exe"); The MSDN reference example code for PathFileExists() is kind of outdated. The reference example used char * directly for PathFileExists() and can not pass compile in visual studio 2011 beta. And also , example code missed the using namespace std; Among all, I think @steveha 's answer is closest to the true problem. Thank you all guys.

最终的工作代码如下所示:

the final working code look like this:

#include "stdafx.h" 
#include <stdio.h>
#include <windows.h>
#include <shlwapi.h>
#include <WinDef.h>
#include <tchar.h>
#pragma comment( lib, "shlwapi.lib")

int _tmain(int argc, _TCHAR* argv[])
{ 
    LPCTSTR lpPath = TEXT("c:\\Windows\\System32\\cmd.exe");
        if( PathFileExists(lpPath) == FALSE)  
    { 
        printf("not exist\n");  
    }else{
            printf("exists!\n"); 
    }
    return 0; 
} 

很抱歉在这里添加了解决方案，但我真的想在一个下午的工作后发表一些想法，希望能帮助其他新手.

Sorry foradding the solution here, but I really want to post some thought after a whole aternoon work and hope that helps other newbies.

推荐答案

我认为问题在于您需要将 char 字符串转换为 TSTR 而您不要那样做.

I believe the problem is that you need to convert a char string to a TSTR and you aren't doing that.

您正在使用类型转换将指针从 char * 类型强制转换为 LPCTSTR 类型，但我认为这实际上不起作用.据我了解， TCHAR 要么与 char 相同，要么就是宽字符".我认为您必须将 TCHAR 设置为宽字符，否则您不会有问题.

You are using a type cast to coerce a pointer from type char * to type LPCTSTR but I think that doesn't actually work. As I understand it, a TCHAR is either the same thing as char or else it is a "wide char". I think you must have TCHAR set to wide char or else you wouldn't have a problem.

我找到了一个 StackOverflow 答案，其中包含可能对您有帮助的信息:

I found a StackOverflow answer that includes information that may help you:

什么在 C/C++(ms) 中将 char[] 转换为/从 tchar[] 的最简单方法是什么?

您可以尝试调用 MultiByteToWideChar() 并查看是否可以解决问题.

You might try calling MultiByteToWideChar() and see if that fixes the problem.

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