String* Adder::downloadUrl(String* url) { DWORD dwSize = 0; LPVOID lpOutBuffer = NULL; BOOL bResults = FALSE; HINTERNET hSession = NULL, hConnect = NULL, hRequest = NULL; // Use WinHttpOpen to obtain a session handle. hSession = WinHttpOpen( L"A WinHTTP Example Program/1.0", WINHTTP_ACCESS_TYPE_DEFAULT_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0); // Specify an HTTP server. if (hSession) hConnect = WinHttpConnect( hSession, L"www.google.com", INTERNET_DEFAULT_HTTP_PORT, 0); // Create an HTTP request handle. if (hConnect) hRequest = WinHttpOpenRequest( hConnect, L"GET", NULL, NULL, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, 0); // Send a request. if (hRequest) bResults = WinHttpSendRequest( hRequest, WINHTTP_NO_ADDITIONAL_HEADERS, 0, WINHTTP_NO_REQUEST_DATA, 0, 0, 0); // End the request. if (bResults) bResults = WinHttpReceiveResponse( hRequest, NULL); // First, use WinHttpQueryHeaders to obtain the size of the buffer. if (bResults) { WinHttpQueryHeaders( hRequest, WINHTTP_QUERY_RAW_HEADERS_CRLF, WINHTTP_HEADER_NAME_BY_INDEX, NULL, &dwSize, WINHTTP_NO_HEADER_INDEX); // Allocate memory for the buffer. if( GetLastError( ) == ERROR_INSUFFICIENT_BUFFER ) { lpOutBuffer = new WCHAR[dwSize/sizeof(WCHAR)]; // Now, use WinHttpQueryHeaders to retrieve the header. bResults = WinHttpQueryHeaders( hRequest, WINHTTP_QUERY_RAW_HEADERS_CRLF, WINHTTP_HEADER_NAME_BY_INDEX, lpOutBuffer, &dwSize, WINHTTP_NO_HEADER_INDEX); } } // Print the header contents. if (bResults) printf("Header contents: \n%S",lpOutBuffer); // Free the allocated memory. delete [] lpOutBuffer; // Report any errors. if (!bResults) printf("Error %d has occurred.\n",GetLastError()); // Close any open handles. if (hRequest) WinHttpCloseHandle(hRequest); if (hConnect) WinHttpCloseHandle(hConnect); if (hSession) WinHttpCloseHandle(hSession); String* retOne; return retOne; } 我想获得响应作为string我在C＃中使用dll，根本不知道vc ++，请build议一种方法。
String * retOne //如何得到响应;
返回retOne;
UPDATE
// Convert a wide Unicode string to an UTF8 string std::string utf8_encode(const std::wstring &wstr) { int size_needed = WideCharToMultiByte(CP_UTF8, 0, &wstr[0], (int)wstr.size(), NULL, 0, NULL, NULL); std::string strTo( size_needed, 0 ); WideCharToMultiByte (CP_UTF8, 0, &wstr[0], (int)wstr.size(), &strTo[0], size_needed, NULL, NULL); return strTo; }
String * retOne = utf8_encode（lpOutBuffer）;
给出错误： 'utf8_encode'：不能将参数1从'LPVOID'转换为'const std :: wstring
请不要发表评论build议使用.net库。
看起来你需要WideCharToMultiByte函数
在这个过程中最难的是了解WideCharToMultiByte函数。
基本上你需要做的是为了得到整个字符串（并避免由于没有空终止字符串的垃圾）首先使用：
int size_needed = WideCharToMultiByte(CP_UTF8, 0, (LPCWCH)lpOutBuffer, -1, NULL, 0, NULL, NULL); char *stringMe = new char[size_needed + 1];
而在WideCharToMultiByte函数中， size_needed是lpMultiByteStr所需的缓冲区大小。
之后，你只需要再次使用该功能，因为现在你有完整的大小：
WideCharToMultiByte(CP_UTF8, 0, (LPCWCH)lpOutBuffer, -1, stringMe, size_needed, NULL, NULL); stringMe[size_needed + 1] = NULL;
现在你也可以把它转换成String：
std::string serverOutput(stringMe);
尝试这个：
String* retOne = utf8_encode(std::wstring(lpOutBuffer));
要么
String* retOne = utf8_encode(std::wstring((WCHAR*)lpOutBuffer));