What's the meaning of bstr, lpolestr in winapi?

BSTR and LPOLESTR have special meanings - they indicate the the string pointed to is allocated in a special way. String pointed to by BSTR must be allocated with SysAllocString() family functions.
Consequently, what to do with string pointed to by BSTR?
String pointed to by BSTR must be allocated with SysAllocString () family functions. String pointed to by LPOLESTR is usually to be allocated with CoTaskMemAlloc () (this should be looked up in the documentation to the COM call accepting/returning it).
Also Know, what's the meaning of BSTR and LPWSTR? LPTSTR and LPWSTR and similar defines are really just defines. BSTR and LPOLESTR have special meanings - they indicate the the string pointed to is allocated in a special way.
In addition, what kind of data type is a BSTR?
A BSTR (Basic string or binary string) is a string data type that is used by COM, Automation, and Interop functions.
Next, which is BSTR wrapper for the Visual Basic string type?
_bstr_t -- A C++ class wrapper for the Visual Basic string type CComBSTR -- Yet another C++ class wrapper for the Visual Basic string type used predominately in ATL code

5 Similar Question Found

What is the difference between bstr and lpolestr?

BSTR and LPOLESTR have special meanings - they indicate the the string pointed to is allocated in a special way. String pointed to by BSTR must be allocated with SysAllocString () family functions.

How to convert wstring to lpolestr in win32?

For Win32 development, "OLE" corresponds to Unicode. For example, in Win32 development, an OLECHAR is simply a wchar_t and an LPOLESTR is a wide character string (e.g. wchar_t* ).

What is the type of lpolestr in ms-oaut?

The following is the type definition for the LPOLESTR type. This type is declared as follows: Is this page helpful? Any additional feedback? Feedback will be sent to Microsoft: By pressing the submit button, your feedback will be used to improve Microsoft products and services.

What's the difference between wchar _ t and lpolestr?

LPOLESTR is a string of OLECHAR which is essentially wchar_t. So LPOLESTR is a null-terminated wchar_t*. LPOLESTR is a typedef created by Microsoft. These are vestiges of an automatic ANSI / Unicode conversion scheme that Microsoft used prior to MFC 4.0 and has since abandoned. For Win32 development, "OLE" corresponds to Unicode.

How to create a variable or constant of type lpolestr?

The problem you have is that LPOLESTR is a typedef for wchar_t*. A compiler will not allow you to convert a const wchar_t* to a wchar_t* without an explicit const_cast. will fix the immediate compilation error as would the more Windows-like and probably preferred by Windows programmers.