更改 Internet 代理设置

引言

更改IE的代理设置是我经常需要做的事情。 最终，我决定自己编写一个工具。 我没有找到关于这方面的清晰说明。 许多文章建议直接修改注册表，但不幸的是，他们的说明不够充分。 大多数都引导我修改注册表中的以下值：-

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyEnable"=dword:00000001
"ProxyServer"=":"
"ProxyOverride"=""
"DisablePasswordCaching"=dword:00000001

详细说明

我测试了它，发现至少在我的电脑上它不起作用。（我通过ADSL连接访问互联网。） 所以我备份了注册表，并通过Internet Explorer修改了代理设置，发现[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections]也被更改了。 因此，我编写了以下代码片段来更改代理设置

void ShowError(long lerr)
{
    LPVOID lpMsgBuf;
    if (!FormatMessage( 
        FORMAT_MESSAGE_ALLOCATE_BUFFER | 
        FORMAT_MESSAGE_FROM_SYSTEM | 
        FORMAT_MESSAGE_IGNORE_INSERTS,
        NULL,
        lerr,
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
        (LPTSTR) &lpMsgBuf,
        0,
        NULL ))
    {
        return;
    }
    MessageBox( NULL, (LPCTSTR)lpMsgBuf, "Error", MB_OK | MB_ICONINFORMATION );
    LocalFree( lpMsgBuf );
}
void CieproxyDlg::OnBnClickedOk()
{//set proxy server
    UpdateData();
    GetDlgItemText(IDC_EDIT1,m_sIEProxy);
    HKEY hk;
    LONG lret=RegOpenKeyEx(HKEY_CURRENT_USER,
        "Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings",
        NULL,KEY_WRITE|KEY_SET_VALUE,&hk);
    if(lret==ERROR_SUCCESS&&NULL!=hk)
    {
        TCHAR* pbuf=m_sIEProxy.GetBuffer(1);
        lret=RegSetValueEx( hk,"ProxyServer",NULL,REG_SZ,pbuf,m_sIEProxy.GetLength());
        DWORD dwenable=1;
        lret=RegSetValueEx(hk,"ProxyEnable",NULL,REG_DWORD,
           (LPBYTE)&dwenable,sizeof(dwenable));
        RegCloseKey(hk);
    }
    const TCHAR* keyname3=_T(
      "software\\Microsoft\\windows\\currentversion\\Internet Settings\\Connections");
    lret=RegOpenKeyEx(HKEY_CURRENT_USER,keyname3,NULL,
        KEY_READ|KEY_WRITE|KEY_SET_VALUE,&hk);
    if(lret==ERROR_SUCCESS&&NULL!=hk)
    {
        DWORD dwtype;
        char pbuf[256];
        DWORD dwlen=sizeof(pbuf);
        const char* valname="Connection to adsl3";
        lret=RegQueryValueEx(hk,valname,NULL,&dwtype,pbuf,&dwlen);
        if(lret!=ERROR_SUCCESS)
        {
            ShowError(lret);
        }
        pbuf[8] = 3;//enable proxy
        pbuf[4]=pbuf[4]+1;
        const char* p=m_sIEProxy.GetBuffer(1);
        memcpy(pbuf+16,p,m_sIEProxy.GetLength());
        char c=0;
        for(int i=m_sIEProxy.GetLength();i<20;i++)
            pbuf[16+i]=c;
        m_sIEProxy.ReleaseBuffer();
        lret=RegSetValueEx(hk,valname,NULL,REG_BINARY,pbuf,dwlen);
        RegCloseKey(hk);
    }
    DWORD dwret;
    SendMessageTimeout(HWND_BROADCAST,WM_SETTINGCHANGE,NULL,NULL,
        SMTO_NORMAL,1000,&dwret);
}

void CieproxyDlg::OnBnClickedDisableProxy()
{
    UpdateData();
    GetDlgItemText(IDC_EDIT1,m_sIEProxy);
    HKEY hk;
    LONG lret=RegOpenKeyEx(HKEY_CURRENT_USER,
        "Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings",
        NULL,KEY_WRITE|KEY_SET_VALUE,&hk);
    if(lret==ERROR_SUCCESS&&NULL!=hk)
    {
        DWORD dwenable=0;
        lret=RegSetValueEx(hk,"ProxyEnable",NULL,REG_DWORD,
            (LPBYTE)&dwenable,sizeof(dwenable));
        RegCloseKey(hk);
    }
    const TCHAR* keyname3=_T(
      "software\\Microsoft\\windows\\currentversion\\Internet Settings\\Connections");
    lret=RegOpenKeyEx(HKEY_CURRENT_USER,keyname3,
        NULL,KEY_READ|KEY_WRITE|KEY_SET_VALUE,&hk);
    if(lret==ERROR_SUCCESS&&NULL!=hk)
    {
        DWORD dwtype;
        char pbuf[256];
        DWORD dwlen=sizeof(pbuf);
        const char* valname="Connection to adsl3";
        lret=RegQueryValueEx(hk,valname,NULL,&dwtype,pbuf,&dwlen);
        if(lret!=ERROR_SUCCESS)
        {
            ShowError(lret);
        }
        pbuf[8] = 1;//enable proxy
        pbuf[4]=pbuf[4]+1;
        lret=RegSetValueEx(hk,valname,NULL,REG_BINARY,pbuf,dwlen);
        RegCloseKey(hk);
    }
    DWORD dwret;
    SendMessageTimeout(HWND_BROADCAST,WM_SETTINGCHANGE,NULL,NULL,SMTO_NORMAL,
        1000,&dwret);
}

上述代码的问题是，现有的Internet Explorer实例不知道设置的更改。 此外，直接修改注册表不是一种优雅的方法。那么以下方法会更具吸引力

BOOL SetConnectionOptions(LPCTSTR conn_name,LPCTSTR proxy_full_addr)
{
    //conn_name: active connection name. 
    //proxy_full_addr : eg "210.78.22.87:8000"
    INTERNET_PER_CONN_OPTION_LIST list;
    BOOL    bReturn;
    DWORD   dwBufSize = sizeof(list);
    // Fill out list struct.
    list.dwSize = sizeof(list);
    // NULL == LAN, otherwise connectoid name.
    list.pszConnection = conn_name;
    // Set three options.
    list.dwOptionCount = 3;
    list.pOptions = new INTERNET_PER_CONN_OPTION[3];
    // Make sure the memory was allocated.
    if(NULL == list.pOptions)
    {
        // Return FALSE if the memory wasn't allocated.
        OutputDebugString("failed to allocat memory in SetConnectionOptions()");
        return FALSE;
    }
    // Set flags.
    list.pOptions[0].dwOption = INTERNET_PER_CONN_FLAGS;
    list.pOptions[0].Value.dwValue = PROXY_TYPE_DIRECT |
        PROXY_TYPE_PROXY;

    // Set proxy name.
    list.pOptions[1].dwOption = INTERNET_PER_CONN_PROXY_SERVER;
    list.pOptions[1].Value.pszValue = proxy_full_addr;//"http://proxy:80";

    // Set proxy override.
    list.pOptions[2].dwOption = INTERNET_PER_CONN_PROXY_BYPASS;
    list.pOptions[2].Value.pszValue = "local";

    // Set the options on the connection.
    bReturn = InternetSetOption(NULL,
        INTERNET_OPTION_PER_CONNECTION_OPTION, &list, dwBufSize);

    // Free the allocated memory.
    delete [] list.pOptions;
    InternetSetOption(NULL, INTERNET_OPTION_SETTINGS_CHANGED, NULL, 0);
    InternetSetOption(NULL, INTERNET_OPTION_REFRESH , NULL, 0);
    return bReturn;
}
BOOL DisableConnectionProxy(LPCTSTR conn_name)
{
    //conn_name: active connection name. 
    INTERNET_PER_CONN_OPTION_LIST list;
    BOOL    bReturn;
    DWORD   dwBufSize = sizeof(list);
    // Fill out list struct.
    list.dwSize = sizeof(list);
    // NULL == LAN, otherwise connectoid name.
    list.pszConnection = conn_name;
    // Set three options.
    list.dwOptionCount = 1;
    list.pOptions = new INTERNET_PER_CONN_OPTION[list.dwOptionCount];
    // Make sure the memory was allocated.
    if(NULL == list.pOptions)
    {
        // Return FALSE if the memory wasn't allocated.
        OutputDebugString("failed to allocat memory in DisableConnectionProxy()");
        return FALSE;
    }
    // Set flags.
    list.pOptions[0].dwOption = INTERNET_PER_CONN_FLAGS;
    list.pOptions[0].Value.dwValue = PROXY_TYPE_DIRECT  ;
    // Set the options on the connection.
    bReturn = InternetSetOption(NULL,
        INTERNET_OPTION_PER_CONNECTION_OPTION, &list, dwBufSize);
    // Free the allocated memory.
    delete [] list.pOptions;
    InternetSetOption(NULL, INTERNET_OPTION_SETTINGS_CHANGED, NULL, 0);
    InternetSetOption(NULL, INTERNET_OPTION_REFRESH , NULL, 0);
    return bReturn;
}

使用方法非常简单明了

//set proxy
    const char* connection_name="Connection to adsl3";
    SetConnectionOptions(connection_name,"62.81.236.23:80");
//disable proxy 
    DisableConnectionProxy(connection_name);
    

现有的Internet Explorer实例通过INTERNET_OPTION_SETTINGS_CHANGED 和 INTERNET_OPTION_REFRESH 得到通知