如何将char *转换为LPCWSTR？

问题描述

我知道这已经在SO的几个问题中讨论过了，但是这些解决方案都没有为我工作。

I know this has already been discussed in several questions on SO, but none of those solutions have worked for me.

我从一个 char * ，因为这是一个将从VBA调用的DLL，并且 char * 是VBA将字符串传递给DLL所必需的。

I start with a char* because this is for a DLL that will be called from VBA, and char* is necessary for VBA to pass a string to the DLL.

我需要返回一个 LPCWSTR ，因为这是我要调用的API函数的输入参数，并且我无法通过在属性窗口中从Unicode切换为多字节字符集来启用转换，因为API具有以下代码：

I need to return a LPCWSTR because that's the input parameter for the API function I'm trying to call, and I can't enable casting by switching from Unicode to multi-byte character set in the Properties window, because the API has this code:

#if !defined(UNICODE) && !defined(NOUNICODE)
#error UNICODE is not defined. UNICODE must be defined for correct API arguments.
#endif

我试过：

LPCWSTR convertCharArrayToLPCWSTR(char* charArray)
    {
        const char* cs=charArray;
        wchar_t filename[4096] = {0};
        MultiByteToWideChar(0, 0, cs[1], strlen(cs[1]), filename, strlen(cs[1]));
    }

出现以下错误：

error C2664: 'strlen' : cannot convert parameter 1 from 'const char' to 'const char *'
error C2664: 'MultiByteToWideChar' : cannot convert parameter 3 from 'const char' to 'LPCCH'

我试过这个：

size_t retVal;
const char * cs = charArray;
size_t length=strlen(cs);
wchar_t * buf = new wchar_t[length]();  // value-initialize to 0 (see below)
size_t wn = mbsrtowcs_s(&retVal,buf,20, &cs, length + 1, NULL);
return buf;

这个编译好，但是当我传递一个示例字符串xyz.xlsx c $ c> mbsrtowcs_s（）将 buf 设置为空字符串： L

This compiled ok, but when I passed it an example string of "xyz.xlsx", mbsrtowcs_s() set buf to an empty string: L""

那么，如何进行此转换？

So, how do I make this conversion?

推荐答案

cs 是 const char * ， cs [1] 是一个 const char 。 C ++不会将它转换为指针，因为在大多数情况下这是没有意义的。

Since cs is a const char*, cs[1] is a const char. C++ won't convert it to a pointer for you, because in most cases that doesn't make sense.

你可以改为&如果意图是跳过第一个字符，则cs [1] 或 cs + 1 （这就是当你传递一个指针到第1个元素时，你在做什么;在C ++中，索引从0开始。）如果意图是传递整个字符串，那么只需传递 cs 。

You could instead say &cs[1] or cs+1 if the intent is to skip the first char. (That's what you're doing when you pass a pointer to the 1th element; in C++, indexes start at 0.) If the intent is to pass the whole string, then just pass cs.

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