public async Task LoadCustomScheme() { await Run(async() => { var embeddedResourceUrl = new ResourceUrl(GetType().Assembly, "Resources", "EmbeddedHtml.html"); var taskCompletionSource = new TaskCompletionSource <bool>(TaskCreationOptions.RunContinuationsAsynchronously); void OnNavigated(string url, string frameName) { if (url != UrlHelper.AboutBlankUrl) { TargetView.Navigated -= OnNavigated; taskCompletionSource.SetResult(true); } } TargetView.Navigated += OnNavigated; TargetView.LoadResource(embeddedResourceUrl); await taskCompletionSource.Task; var content = await TargetView.EvaluateScript <string>("document.documentElement.innerText"); Assert.AreEqual("test", content); }); }