set auto proxy url for IE or windows system proxy

ieSetAutoProxyURL.cpp

#include "stdio.h"
#include "windows.h"
#include "wininet.h"
#pragma comment(lib, "wininet.lib")
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
    LPWSTR *szArgList;
    int argCount; 
    szArgList = CommandLineToArgvW(GetCommandLine(), &argCount);
    if (szArgList == NULL)
    {
        MessageBox(NULL, L"Unable to parse command line", L"Error", MB_OK);
        return 10;
    }
    if (argCount == 1) return 1;
    
    char buff[256];
    strcpy_s(buff, szCmdLine);
    int buffSize = MultiByteToWideChar(CP_ACP, 0, buff, -1, NULL, 0);
    LPWSTR proxy = new WCHAR[buffSize];
    MultiByteToWideChar(CP_ACP, 0, buff, -1, proxy, buffSize);

    INTERNET_PER_CONN_OPTION_LIST List;
    INTERNET_PER_CONN_OPTION Option[2];
    unsigned long nSize = sizeof(INTERNET_PER_CONN_OPTION_LIST);

    Option[0].dwOption = INTERNET_PER_CONN_AUTOCONFIG_URL;
    Option[0].Value.pszValue = proxy;
    Option[1].dwOption = INTERNET_PER_CONN_FLAGS;
    Option[1].Value.dwValue = PROXY_TYPE_AUTO_PROXY_URL;

    if (strcmp(szCmdLine,"off"))
        Option[1].Value.dwValue = PROXY_TYPE_AUTO_PROXY_URL;
    else{
        Option[1].Value.dwValue = PROXY_TYPE_DIRECT;
        Option[0].Value.pszValue = NULL;
    }        

    DWORD ConnectedState = 0;
    LPDWORD lpdwFlags = (LPDWORD)&ConnectedState;
    char ConnectedName[4096] = {'0',};
    LPTSTR lpszConnectionName = (LPTSTR)ConnectedName;
    BOOL internetconn = InternetGetConnectedStateEx(lpdwFlags, lpszConnectionName, 4096, NULL);
    List.dwSize = sizeof(INTERNET_PER_CONN_OPTION_LIST);

    if ((ConnectedState & INTERNET_CONNECTION_LAN) == INTERNET_CONNECTION_LAN ){
        List.pszConnection = NULL;
    }else{
        List.pszConnection = lpszConnectionName;
    }

    List.dwOptionCount = 2;
    List.dwOptionError = 0;
    List.pOptions = Option;
    if(!InternetSetOption(NULL, INTERNET_OPTION_PER_CONNECTION_OPTION, &List, nSize))
        printf("InternetSetOption failed! (%d)\n", GetLastError());

    InternetSetOption(NULL,INTERNET_OPTION_SETTINGS_CHANGED,NULL,NULL);
    InternetSetOption(NULL, INTERNET_OPTION_REFRESH, NULL,NULL);
    //The connection settings for other instances of Internet Explorer.
    return 0;
}

ieSetAutoProxyURL http://127.0.0.1:8086/proxy.pac //set goagent auto proxy on
ieSetAutoProxyURL http://127.0.0.1:7777/pac //set cow auto proxy on
ieSetAutoProxyURL off //direct connect

windows 10 INTERNET_OPTION_SETTINGS_CHANGED and INTERNET_OPTION_REFRESH not work,the browser need to restart