CEF3使用类似Google Chrome一样的方式，通过命令行参数传递代理配置。
--proxy-server=host:port
Specify the HTTP/SOCKS4/SOCKS5 proxy server to use for requests. An individual proxy
server is specified using the format:
[<proxy-scheme>://]<proxy-host>[:<proxy-port>]
Where <proxy-scheme> is the protocol of the proxy server, and is one of:
"http", "socks", "socks4", "socks5".
If the <proxy-scheme> is omitted, it defaults to "http". Also note that "socks" is equivalent to
"socks5".
Examples:
--proxy-server="foopy:99"
Use the HTTP proxy "foopy:99" to load all URLs.
--proxy-server="socks://foobar:1080"
Use the SOCKS v5 proxy "foobar:1080" to load all URLs.
--proxy-server="sock4://foobar:1080"
Use the SOCKS v4 proxy "foobar:1080" to load all URLs.
--proxy-server="socks5://foobar:66"
Use the SOCKS v5 proxy "foobar:66" to load all URLs.
It is also possible to specify a separate proxy server for different URL types, by prefixing
the proxy server specifier with a URL specifier:
Example:
--proxy-server="https=proxy1:80;http=socks4://baz:1080"
Load https://* URLs using the HTTP proxy "proxy1:80". And load http://*
URLs using the SOCKS v4 proxy "baz:1080".
--no-proxy-server
Disables the proxy server.
--proxy-auto-detect
Autodetect proxy configuration.
--proxy-pac-url=URL
Specify proxy autoconfiguration URL.
如果代理请求授权，CefRequestHandler::GetAuthCredentials()回调会被调用。如果isProxy参数为true，则需要返回用户名和密码。
bool MyHandler::GetAuthCredentials(
CefRefPtr<CefBrowser> browser,
CefRefPtr<CefFrame> frame,
bool isProxy,
const CefString& host,
int port,
const CefString& realm,
const CefString& scheme,
CefRefPtr<CefAuthCallback> callback) {
if (isProxy) {
// Provide credentials for the proxy server connection.
callback->Continue("myuser", "mypass");
return true;
}
return false;
}
CEF任意请求代理
准确说是2015年10月7日之后）的CEF加入另一种更加灵活的方式，即任意请求代理
这种方式的原理是在进行每次请求的时候CEF给应用一次机会让应用可以修改请求相关的参数。要实现这一点，我们需要自己的CefRequestHandler，然后重载OnBeforeBrowse和GetAuthCredentials（不一定需要）两个方法，定义如下：
```
class MyRequestHandler final : public CefRequestHandler {public:
virtual bool OnBeforeBrowse(CefRefPtr<CefBrowser> browser,
CefRefPtr<CefFrame> frame,
CefRefPtr<CefRequest> request, bool is_redirect); // 可选，根据是否需要认证
virtual bool GetAuthCredentials(CefRefPtr<CefBrowser> browser,
CefRefPtr<CefFrame> frame, bool isProxy, const CefString& host, int port, const CefString& realm, const CefString& scheme,
CefRefPtr<CefAuthCallback> callback);private:
IMPLEMENT_REFCOUNTING(MyRequestHandler);
};
```
```
bool MyRequestHandler::OnBeforeBrowse(
CefRefPtr<CefBrowser> browser,
CefRefPtr<CefFrame> frame,
CefRefPtr<CefRequest> request,
bool is_redirect) {
CefRefPtr<CefRequestContext> context =
browser->GetHost()->GetRequestContext();
CefString error;
CefRefPtr<CefDictionaryValue> dict = CefDictionaryValue::Create();
dict->SetString("mode", "fixed_servers");
dict->SetString("server", "myproxy:808");
CefRefPtr<CefValue> value = CefValue::Create();
value->SetDictionary(dict);
context->SetPreference("proxy", value, error); return false;
}
```
其中mode可以取值以下任一：
fixed_servers
pac_script
auto_detect
system
direct
而当mode为fixed_servers时需要指定server参数，当mode为pac_script时需要指定pac_url参数。
如果代理需要认证，那么需要同时实现：
`
bool MyRequestHandler::GetAuthCredentials(
CefRefPtr<CefBrowser> browser,
CefRefPtr<CefFrame> frame, bool isProxy, const CefString& host, int port, const CefString& realm, const CefString& scheme,
CefRefPtr<CefAuthCallback> callback) { if (isProxy) {
callback->Continue("myuser", "mypass"); return true;
} return false;
}
`
