Could someone explain to me how the CefSharp LoadHtml function works?
LoadHtml(string html, string url)
What do the html and url parameters represent?
I am interested in loading a page from a raw HTML string into the CefSharp browser.
Answer
Update: CefSharp has a new
LoadHtml(string html)method that loads the HTML as a base64-encoded data URI. It is more reliable that theLoadHtml(string html, string url)method described below.
In LoadHtml(string html, string url):
html is your HTML string, e.g. "<html><body>Hello world</body></html>". Actually, you can even put other content in the string, such as SVG markup, as long as Chromium can understand it.
url is needed because your HTML code may contain JavaScript that tries to perform AJAX calls, and the web browser needs to understand what security restrictions apply. The scheme (e.g. "http:", "about:") and domain (e.g. "localhost", "google.com") affect behaviour such as clicking on links, AJAX requests, iframes, etc.
If you want to simply render static HTML, make the url something unique such as http://rendering/ (so that the resource handler does not overlap with a real url on the web). If you need to load the HTML and then interact with it or perform AJAX calls, choose a url that matches the domain you want to interact with - for example, if you want to make an alternative Google home page and perform AJAX search queries, you will want to use https://www.google.com/ as your URL so you can communicate with it.
You can see the source code for LoadHtml here.
What CefSharp does is:
- Register a resource handler for the given
url. - Call
Load(url)to tell Chromium to load the givenurl.
Then, under the hood:
- Chromium requests the
url. - The resource handler intercepts the request, and returns your
html. - Chromium renders your
htmlinstead of the real content of the URL.