在UWP app WebBrowser控件中更改用户代理标头

Question

How do I globally change user-agent header in UWP app WebBrowser control?

I can change user-agent header in initial url loaded in webbrwser control

httpRequestMessage.Headers.Append("User-Agent", ...); 
browser.NavigateWithHttpRequestMessage(httpRequestMessage); 

but any internal link redirect from webpage does not seem to use this custom user-agent header.

Answer 1

Unlike Android or iOS, Microsoft does not expose a way to globally change the user-agent in a WebView component.

For individual GET or POST requests, you can set the UA like this:

Uri^ targetURL = ref new Uri("http://www.yourUrlString.com");
HttpClient^ newRequest = ref new HttpClient();
auto headers = newRequest->DefaultRequestHeaders;
headers->UserAgent->TryParseAdd("your user-agent string here");
create_task(newRequest->GetAsync(targetUrl)).then([=](HttpResponseMessageData^ data) 
{
   //Your callback here
});

With that technique, it is possible to connect to the WebView's NavigationStarting event and intercept each request, but I would strongly recommend against it.

The WebViewNavigationStartingEventArgs only expose the Uri you were going to navigate to, and the ability to cancel the request. It does not expose what type of request it was, nor where the intent came from. Because of this, it is impossible to recreate the original navigation intention and you will start to see navigational bugs.

For example, some web pages have JavaScript elements that make POST requests on button clicks, and if you are intercepting those requests and recreating them as GET requests, the requests will fail and the user's action will be lost.

Until Microsoft changes this behavior in the WebView, I do not think it is possible to meaningfully change the UA.