public async Task RestoreSavedNavigation_ClearsOldForwardNavigation()
{
await ExecuteOnUIThread(() =>
{
var frame = new FrameFacadeAdapter(new Frame());
var sessionStateService = new MockSessionStateService();
var frameSessionState = new Dictionary<string, object>();
sessionStateService.GetSessionStateForFrameDelegate = (currentFrame) => frameSessionState;
var navigationService = new FrameNavigationService(frame, (pageToken) => typeof(MockPageWithViewModel), sessionStateService);
navigationService.Navigate("Page1", 1);
Assert.AreEqual(1, frameSessionState.Count, "VM 1 state only");
navigationService.Navigate("Page2", 2);
Assert.AreEqual(2, frameSessionState.Count, "VM 1 and 2");
navigationService.Navigate("Page3", 3);
Assert.AreEqual(3, frameSessionState.Count, "VM 1, 2, and 3");
navigationService.GoBack();
Assert.AreEqual(2, ((Dictionary<string, object>)frameSessionState["ViewModel-2"]).Count);
Assert.AreEqual(3, frameSessionState.Count, "VM 1, 2, and 3");
navigationService.Navigate("Page4", 4);
Assert.AreEqual(0, ((Dictionary<string,object>)frameSessionState["ViewModel-2"]).Count);
Assert.AreEqual(3, frameSessionState.Count, "VM 1, 2, and 4");
});
}
public async Task GoBack_When_CanGoBack()
{
await ExecuteOnUIThread(() =>
{
var frame = new FrameFacadeAdapter(new Frame());
var sessionStateService = new MockSessionStateService();
sessionStateService.GetSessionStateForFrameDelegate = (currentFrame) => new Dictionary<string, object>();
var navigationService = new FrameNavigationService(frame, (pageToken) => typeof(MockPage), sessionStateService);
bool resultFirstNavigation = navigationService.Navigate("MockPage", 1);
Assert.IsInstanceOfType(frame.Content, typeof(MockPage));
Assert.AreEqual(1, ((MockPage)frame.Content).PageParameter);
Assert.IsFalse(navigationService.CanGoBack());
bool resultSecondNavigation = navigationService.Navigate("Mock", 2);
Assert.IsInstanceOfType(frame.Content, typeof(MockPage));
Assert.AreEqual(2, ((MockPage)frame.Content).PageParameter);
Assert.IsTrue(navigationService.CanGoBack());
navigationService.GoBack();
Assert.IsInstanceOfType(frame.Content, typeof(MockPage));
Assert.AreEqual(1, ((MockPage)frame.Content).PageParameter);
Assert.IsFalse(navigationService.CanGoBack());
});
}
