使用Windows API发送HTTP(S)请求

#include <Windows.h>
#include <winhttp.h>
#include <stdio.h>
int main()
{
    HINTERNET sessionHandle = WinHttpOpen(L"WinHttp Example",WINHTTP_ACCESS_TYPE_DEFAULT_PROXY,WINHTTP_NO_PROXY_NAME,WINHTTP_NO_PROXY_BYPASS,0);
    if (sessionHandle)
    {
        HINTERNET connectionHandle = WinHttpConnect(sessionHandle,L"example.com",INTERNET_DEFAULT_HTTP_PORT,0);
        if (connectionHandle)
        {
            HINTERNET requestHandle = WinHttpOpenRequest(connectionHandle,L"GET",L"",NULL,WINHTTP_NO_REFERER,WINHTTP_DEFAULT_ACCEPT_TYPES,0);
            if (requestHandle)
            {
                BOOL success = WinHttpSendRequest(requestHandle,WINHTTP_NO_ADDITIONAL_HEADERS,0,WINHTTP_NO_REQUEST_DATA,0);
                if (success)
                {
                    success = WinHttpReceiveResponse(requestHandle,NULL);
                    if (success)
                    {
                        DWORD dwSize;
                        do
                        {
                            dwSize = 0;
                            LPSTR pszOutBuffer;
                            DWORD dwDownloaded = 0;
                            if (!WinHttpQueryDataAvailable(requestHandle,&dwSize))
                            {
                                printf("Error %u in WinHttpQueryDataAvailable.n",GetLastError());
                                break;
                            }
                            // No more available data.
                            if (!dwSize)
                                break;
                            // Allocate space for the buffer.
                            pszOutBuffer = new char[dwSize + 1];
                            if (!pszOutBuffer)
                            {
                                printf("Out of memoryn");
                                break;
                            }
                            // Read the Data.
                            ZeroMemory(pszOutBuffer,dwSize + 1);
                            if (!WinHttpReadData(requestHandle,(LPVOID)pszOutBuffer,dwSize,&dwDownloaded))
                            {
                                printf("Error %u in WinHttpReadData.n",GetLastError());
                            }
                            else
                            {
                                printf("%s",pszOutBuffer);
                            }
                            // Free the memory allocated to the buffer.
                            delete[] pszOutBuffer;
                            // This condition should never be reached since WinHttpQueryDataAvailable
                            // reported that there are bits to read.
                            if (!dwDownloaded)
                                break;
                        } while (dwSize > 0);
                    }
                    else
                    {
                        // Report any errors.
                        printf("Error %d has occurred.n",GetLastError());
                    }
                }
                else
                {
                    printf("Request failedn");
                }
                WinHttpCloseHandle(requestHandle);
            }
            else
            {
                printf("Invalid request handlen");
            }
            WinHttpCloseHandle(connectionHandle);
        }
        else
        {
            printf("Invalid connection handlen");
        }
        WinHttpCloseHandle(sessionHandle);
    }
    else
    {
        printf("Invalid WinHTTP-session handlen");
    }
    system("pause");
    return 0;
}