如何将 BSTR 与 c/c++ 中的字符串进行比较?

wprintf(L"Selecting Audio Input Device: %s
", 
                            varName.bstrVal);

if(0 == strcmp(varName.bstrVal, "IP Camera [JPEG/MJPEG]"))...

以上报道:

error C2664: 'strcmp' : cannot convert parameter 1 from 'BSTR' to 'const char *'

推荐答案

你必须使用 wcscmp 代替:

if(0 == wcscmp(varName.bstrVal, L"IP Camera [JPEG/MJPEG]"))
{
}

这里是 描述BSTR 数据类型，它有一个长度前缀和一个真正的字符串部分，它只是一个 WCHAR 字符数组.它还有 2 个 NULL 终止符.

Here is a description of the BSTR data type, it has a length prefix and a real string part which is just an array of WCHAR characters. It also has 2 NULL terminators.

唯一需要注意的是 BSTR 数据类型可以在字符串部分包含嵌入的 NULL，因此 wcscmp 仅在 BSTR 不包含嵌入的 NULL 的情况下有效(即可能是大多数情况).

The only thing to look out for is that the BSTR data type can contain embedded NULLs in the string portion, so wcscmp will only work in the cases where the BSTR does not contain embedded NULLs (which is probably most cases).