具体代码是:

#include <stdio.h>
#include <stdlib.h>

#include <wchar.h>
#include <locale.h>

int char2wchar(char* pSrc, wchar_t* pDest)
{
    if (pSrc == NULL || pDest == NULL)
    {
        return 0;
    }

    setlocale(LC_CTYPE, "zh_CN.utf8");
    int w_size = mbstowcs(NULL, pSrc, 0) + 1;
    //w_size=0说明出错了。可能有非法字符,也可能是locale设置不对。
    if (w_size == 0)
    {
        return -1;
    }

    int ret = mbstowcs(pDest, pSrc, strlen(pSrc)+1);
    if (ret <= 0)
    {
        return -1;
    }

    return w_size;
}


int main()
{
    wchar_t wstr[32]     = {0};
    char*   source       = "泰山";

    int count = char2wchar(source, &(wstr[0]));
}