拜托C++、C#高手，把下边的代码翻译成C#的

Question

LPWSTR proxyName;

int on = 1;

if (on) {
    proxyName = L"127.0.0.1:3125";
}
else {
    proxyName = 0;
}

INTERNET_PER_CONN_OPTION_LIST OptionList;
INTERNET_PER_CONN_OPTION Option[3];
unsigned long listSize = sizeof(INTERNET_PER_CONN_OPTION_LIST);
Option[0].dwOption = INTERNET_PER_CONN_PROXY_SERVER;
Option[1].dwOption = INTERNET_PER_CONN_FLAGS;
Option[2].dwOption = INTERNET_PER_CONN_PROXY_BYPASS;
OptionList.dwSize = sizeof(INTERNET_PER_CONN_OPTION_LIST);
OptionList.pszConnection = NULL;
OptionList.dwOptionCount = 3;
OptionList.dwOptionError = 0;

DWORD proxyType = PROXY_TYPE_DIRECT; // this proxy type disables any proxy server

if (proxyName) {
    if (proxyName[0]) {
        proxyType = PROXY_TYPE_PROXY; // a name has been passed, so choose the correct proxy type for enabling the proxy server
    }
}

Option[0].Value.pszValue = (LPWSTR)proxyName;
Option[1].Value.dwValue = proxyType;
if (on) {
    Option[2].Value.pszValue = (LPWSTR)L"";
}
else {
    Option[2].Value.pszValue = (LPWSTR)L"";
}
OptionList.pOptions = Option;

if (!InternetSetOption(0, INTERNET_OPTION_PER_CONNECTION_OPTION, &OptionList, listSize)) {
    // handle error
}

InternetSetOption(0, INTERNET_OPTION_REFRESH, NULL, NULL);

=====================================================
就是上边这些代码，如果写成用C#调用WinInet的，应该怎么写？

Answer 1

代码就是设置Proxy地址，在C#里面可以直接使用WebRequest和WebProxy来建立连接和设置代理。

/// Reference: 
///   http://msdn.microsoft.com/en-us/library/system.net.webrequest.proxy(v=vs.110).aspx
/// 
/// Usage: 
///   createRequestWithProxy("http://www.segmentfault.com", "127.0.0.1:3125")
WebRequest createRequestWithProxy(string, url, string proxyAddress) {
    WebRequest webRequest = WebRequest.Create(url);
    WebProxy webProxy = (WebProxy)webRequest.Proxy;

    try {
        webProxy.Address=new Uri(proxyAddress);
    } catch(UriFormatException e) {
        // do nothing
    }

    return webRequest;
}

Answer 2

WebRequest req = WebRequest.Create(url);
req.Proxy = new WebProxy("127.0.0.1:3125");

当然如果是http的话，你也可以用WebClient

WebClient wc = new WebClient();
wc.Proxy = new WebProxy("127.0.0.1:3125");