⚠️ This repo uses UIWebView but it has been deprecated. As of April 2020, Apple announced they will reject new apps still referencing it. — UIWebView Deprecation and Xamarin.Forms - Xamarin Blog
Xamarin WebView With Custom Headers
An example that shows how to send request headers in a Xamarin Webview using custom renderers. An example that shows how define custom headers values from shared code is also included.
Simple version
The request is filled with a custom header which then can be fetched in the website scanning the request's headers:
Android
Android requires the INTERNET permission in order to load a website from the Internet.
Basically, you need to define a WebViewClient and override the ShouldOverrideUrlLoading(WebView view, string url) function, then set the headers and perform the request calling View.LoadUrl(url, headers).
iOS
iOS doesn't require any special configuration.
var headerKey = new NSString("A-custom-header");
var headerValue = new NSString("a custom value");
var dictionary = new NSDictionary(headerKey, headerValue);
webRequest.Headers = dictionary;
Defining custom headers values from shared code
If you want to assign a custom value from shared code to each renderer, take a look at the CustomWebView control and CustomWebViewPage view to see how to achieve this. Basically, we're using Xamarin.Forms custom controls and data bindings to define custom parameters and get the value in each custom renderer.
References
My discussion in Xamarin Forums
Build Information
This project was created in Visual Studio for Mac
Versión: 7.3.3 (build 5)
Template: Xamarin Forms App