| From | To | Sample |
| 字符串常量 | BSTR | Right: BSTR bs = ::SysAllocString(_T("Test string")); … ::SysFreeString(); Wrong: BSTR bs = _T("Test string"); //ERROR |
| LPWSTR / LPCWSTR / WCHAR* / wchar_t | BSTR | Right: LPCTSTR sz1 = _T("Test String"); BSTR bs = ::SysAllocString(sz1); … ::SysFreeString(); Wrong: LPTSTR sz1 = _T("Test String"); BSTR bs = sz1; //ERROR |
| BSTR | LPCWSTR / const WCHAR * / const wchar_t * | Right: BSTR bs = ...; // ... LPCTSTR sz = static_cast<LPCTSTR>bs; ... ::SysFreeString(bs); //Never use sz after this line Wrong: BSTR bs = ...; // ... LPCTSTR sz = bs; ... ::SysFreeString(bs); //Never use sz after this line _tcslen(sz); //ERROR |
| BSTR | LPWSTR / WCHAR* / wchar_t* | Right: BSTR bs = ...; // //... UINT len = ::SysStringLen(bs); // Do not modify the BSTR content by // C/C++ string functions LPTSTR sz = new TCHAR[len+1]; _tcsncpy(sz, bs, len); ::SysFreeString(bs); delete []sz; Wrong: BSTR bs = ...; // //... // Do not modify the BSTR content by // C/C++ string functions LPTSTR sz = bs; //Error |
| CString | BSTR | Right: CString str1 = ...; BSTR bs = str1.AllocSysString(); SomeMethod(bs); // void SomeMethod([in]BSTR) ::SysFreeString(bs); CComBSTR bs1(static_cast<LPCTSTR>(str1)); SomeMethod(static_cast<BSTR> (bs1) ); // void SomeMethod([in] BSTR ) _bstr_t bs2( static_cast<LPCTSTR>(str1)); SomeMethod(static_cast<BSTR> (bs2) ); Wrong: CString str1 = ...; SomeMethod(str1.AllocSysString()); // No one will releasee the return BSTR of // str1.AllocSysString() |
| BSTR | CString | Right: BSTR bs = SysAllocString(_T(“Test”)); CString str1(bs); CString str2; Str2 = bs; SysFreeString(bs); // Never forget this line |
| char* / LPSTR / LPCSTR | BSTR | Right: Solution 1： char str[MAX_STR_LEN] = "ANSI string"; WCHAR wstr[MAX_WSTR_LEN]; // Convert ANSI to Unicode MultiByteToWideChar( CP_ACP, 0, str, strlen(str)+1, wstr, sizeof(wstr)/sizeof(wstr[0]) ); BSTR bs1 = ::SysAllocString(wstr); CString cs = str; BSTR bs2 = cs.AllocSysString() Solution 2： char str[MAX_STR_LEN] = "ANSI string"; _bstr_t bs1(str); CComBSTR bs2(str); Wrong: char *str = "ANSI string"; BSTR bstr1 = SysAllocString( (const OLECHAR*) str); |
| BSTR | char* / LPSTR / LPCSTR | Right: Solution 1： char str[MAX_STR_LEN]; BSTR bs = ::SysAllocString(L"Test"); // Convert ANSI to Unicode WideCharToMultiByte( CP_ACP, 0, (LPCWSTR)bs, -1, str, MAX_STR_LEN, NULL, NULL ); ::SysFreeString(bs); Solution 2： BSTR bs = ::SysAllocString(L"Test"); _bstr_t bs1(bs, false); const char* str = static_cast <const char*> bs1; Wrong: BSTR bstr1 = SysAllocString(L”ANSI string"); char *str = (char*) bstr1; |
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