Navigate to ViewModel From Current View Instead of RootView - ios

Question

Is there a way to navigate to a ViewModel from my current view instead the root view?
I have created a view model that is presented modally from the root view and wish to present a view model within that view.
For example, when calling _navigationService.Navigate<MyViewModel>(); from my modal view, the root view navigates to MyViewModel instead of the current modal view. This leaves my modal screen with a blank page until you dismiss it and see that the navigation has taken place below.
Do I create a custom navigation, or is there a better way of going about this?
EDIT
Here is some code:
My View Model
public class ViewModel1 : MvxViewModel
{
private readonly IMvxNavigationService _navigationService;
public ViewModel1(IMvxNavigationService navigationService)
{
_navigationService = navigationService;
}
public IMvxCommand NavigateCommand => new MvxCommand(ChangeView);
void ChangeView()
{
_navigationService.Navigate<ViewModel2>();
}
}
My View
[MvxModalPresentation(WrapInNavigationController = true, ModalPresentationStyle = UIModalPresentationStyle.Custom, Animated = false)]
public partial class MyView : MvxViewController
{
ViewModel1 VM;
public MyView() : base("MyView", null)
{
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
NavigationController.NavigationBar.Hidden = true;
var set = this.CreateBindingSet<MyView, ViewModel1 >();
set.Bind(NextButton).To(vm => vm.NavigateCommand);
set.Apply();
}
public override void DidReceiveMemoryWarning()
{
base.DidReceiveMemoryWarning();
// Release any cached data, images, etc that aren't in use.
}
}
I would like to have the navigation command present ViewModel2 within the presented modal.

Answer 1

For this kind of customization, you may need a write a custom presenter and there you can fiddle around to achieve whatever you can achieve with native.
I am dropping some hint.
In AppDelegate, inside finish launching.
public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
{
Window = new UIWindow(UIScreen.MainScreen.Bounds);
var presenter = new DelegatingPresenter(this, Window);
var setup = new Setup(this, presenter);
setup.Initialize();
var startup = Mvx.Resolve<IMvxAppStart>();
startup.Start();
---
---
}
DelegatingPresenter looks like:
public class DelegatingPresenter : MvxIosViewPresenter {
private UIWindow currentWindow;
public DelegatingPresenter(AppDelegate appDelegate, UIWindow window)
: base(appDelegate, window) {
currentWindow = window;
--
---
}
protected override void SetWindowRootViewController(UIViewController controller, MvvmCross.iOS.Views.Presenters.Attributes.MvxRootPresentationAttribute attribute = null)
{
base.SetWindowRootViewController(controller, attribute);
}
public override void Show(MvxViewModelRequest request)
{
var viewCreator = Mvx.Resolve<IMvxIosViewCreator>();
var controller = (UIViewController)viewCreator.CreateView(request);
Show((UIViewController)controller);
}
//public override void Show(IMvxIosView view) {
//}
public override void ChangePresentation(MvxPresentationHint hint) {
---
----
}
public override void Close(IMvxViewModel toClose) {
---
----
}
public void Show(UIViewController) {
//if (viewController is IFlyoutNavigationControllerCapable) {
//flyoutPresenter.Show(viewController, flyout);
//}
//else {
//currentWindow.RootViewController = viewController;
//navigationPresenter.Show(viewController, flyout);
//}
//Do your thing here.
}
public bool Close(FlyoutNavigationController flyout) {
---
----
}
}
Here, your point of interest are "show" method override thats gets called when load new ViewModel.
Here you have your rootviewController and new controller that you want to present, so I guess you can take it from here.