private void OnNavigationStarting(IWebViewControl sender, Windows.Web.UI.WebViewControlNavigationStartingEventArgs args)
{
var newNavigationRequested = false;
var cancelRequested = false;
try
{
var url = args.Uri;
// The NavigatingToAboutBlank property indicates whether we are navigating to "about:blank" as a result of navigating
// to a null source, or stream/string navigation.
// We set the NavigatingToAboutBlank bit to true in the void Navigate(Uri) method. When the above conditions are true,
// the NavigatingToAboutBlank is true and the source must be "about:blank"
if (NavigatingToAboutBlank && url != null && url != new Uri("about:blank"))
{
NavigatingToAboutBlank = false;
}
if (!NavigatingToAboutBlank && !Security.CallerHasWebPermission(url))
{
cancelRequested = true;
}
else
{
// When Source is set to null or navigating to stream/string, we navigate to "about:blank" internally.
// Make sure we pass null in the event args
if (NavigatingToAboutBlank)
{
url = null;
}
var a = new WebViewControlNavigationStartingEventArgs(args, url);
// Launching a navigation from the NavigationStarting event handler causes re-entrancy
var lastNavigation = LastNavigation;
// Fire navigating event
OnNavigationStarting(a);
if (LastNavigation != lastNavigation)
{
newNavigationRequested = true;
}
cancelRequested = a.Cancel;
}
}
// Disable to suppress FXCop warning since we really do want to catch all exceptions
#pragma warning disable 6502
catch
{
cancelRequested = true;
}
#pragma warning restore 6502
finally
{
if (cancelRequested && !newNavigationRequested)
{
CleanInternalState();
}
if (cancelRequested || newNavigationRequested)
{
args.Cancel = true;
}
}
}
private void OnFrameNavigationStarting(IWebViewControl sender, Windows.Web.UI.WebViewControlNavigationStartingEventArgs args) => OnFrameNavigationStarting(args);
