How to convert _bstr_t to CString

Question

I have a _bstr_t variable bstrErr and I am having a CString variable csError. How do I set the value which come in

Answer 1

CStringT,CString, CStringA, and CStringW:

• CStringT is a complicated class template based on an arbitrary character type and helper class templates for managing the storage and the features.
• The class CString is a typedef of the template class that uses the TCHAR character type. TCHARis a generic type that resolves to wchar if the macro UNICODE is set, else to char.
• The class CStringA is a typedef of the template class that uses internally the narrow character type char.
• The class CStringW is a typedef of the template class that uses internally the wide character type wchar_t.

I never use CString in code, instead I always use the explicit classes CStringA or CStringW. The classes CString* have constructors that accept narrow and wide strings. The same is true for _bstr_t. Strings of type BSTR must be allocated by the function SysAllocString() that expects an OLECHAR string, hence in Win32/64 a wide string. If you want to copy a _bstr_t that contains Unicode to a CStringA you must convert it to UTF8. I use the classes CW2A and CA2W for conversion.

In the following event function of a Word add-in, I show the use of these types:

STDMETHODIMP CConnect::TestButtonClicked(IDispatch* Command)
{
  BSTR smi = SysAllocString(L"Two smileys