In my opinion, the best way is to actually view it outside of the WinForms app by using whatever the user has chosen to be their default PDF viewer.
WebView2
control is probably the best option. That said, if it's just for displaying a PDF, you may even be able to get away with a WebBrowser
control. Even if it works though, I think I'd still avoid it.If all your users are guaranteed to have a specific component installed, e.g. Adobe Reader, then you could use that. Otherwise, I agree with @JohnH that theWebView2
control is probably the best option. That said, if it's just for displaying a PDF, you may even be able to get away with aWebBrowser
control. Even if it works though, I think I'd still avoid it.