MvvmCross Xamarin.Forms Modal Dialogs - ios

Question

I'm just trying to make my first app with MvvmCross but I already encounter a problem for my app and can't find anything on the web for that. I want to open a specific page as a modal dialog on supported devices (eg. iPads). For my non MvvmCross applications I do this with Rg.Plugin.Popup but I do not want it this way this time. I found a few solutions on how it can be done with native and MvvmCross but nothing about how it is done with Xamarin.Forms in combination to MvvmCross. Did I need to implement a own presenter and filter on the type of my page (because this page should always be modal on supported devices)? And if I do so, is there any example for this?

Answer 1

Using MvvmCross 5.2.0, the following worked for me (on iOS at least; haven't tested on Android):
var bundle = new MvxBundle(new Dictionary<string, string>{ { MvxFormsPagePresenter.ModalPresentationParameter, "true" } });
await _navService.Navigate<MyViewModel>(bundle);
This uses the stock-standard MvxFormsPagePresenter, so you don't have to create your own presenter.

Answer 2

I'm using MVVMCross 7.1.2 here, this was tested on Android only.
In your Views code behind implement IMvxOverridePresentationAttribute with code similar to this.
public MvxBasePresentationAttribute PresentationAttribute(MvxViewModelRequest request)
{
if (request.PresentationValues == null) return null;
if (request.PresentationValues.ContainsKey("NavigationMode") &&
request.PresentationValues["NavigationMode"] == "Modal")
{
return new MvxModalPresentationAttribute
{
WrapInNavigationPage = true,
Animated = false,
NoHistory = true
};
}
return null;
}
All you need to do now, is when Navigating to the view model is just pass a key value pair as the parameter like this
await NavigationService.Navigate<MainViewModel>(new MvxBundle(new Dictionary<string, string> { { "NavigationMode", "Modal" } }));
That's it... easy as that !