How to get the current active view in a region using PRISM?

Question

I know that i can get all the registered views in a region with :

var vs = mRegionManager.Regions[RegionNames.MainRegionStatic].Views.ToList();

and i can see there is the following code :

mRegionManager.Regions[RegionNames.MainRegionStatic].ActiveViews

which is giving a list of Active View, but I'm having my region attached to a ContentControl which always has a single ActiveView. Am i misunderstood or is there a way to get the single active view?

Navid Rahmani · Accepted Answer · 2011-06-15T14:19:46.440

15

var singleView = regionManager.Regions["MyRegion"].ActiveViews.FirstOrDefault();

edited Jun 15 '11 at 14:19

answered Jun 15 '11 at 14:05

Navid Rahmani

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Great that worked, but how is it that we have a collection for that? – Ehsan Zargar Ershadi Jun 15 '11 at 14:27
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because [SingleActiveRegion](http://msdn.microsoft.com/en-us/library/microsoft.practices.composite.presentation.regions.singleactiveregion.aspx) inherits Region – Navid Rahmani Jun 15 '11 at 14:33
Is there a way to get existing VMs using the IoC container (in my case DryIoc)? I tried `this == _Container.Resolve` from the `ShellViewModel` and it evaluated to `false`. – Shimmy Weitzhandler Nov 27 '17 at 17:09

score 5 · Answer 2 · edited Dec 05 '11 at 03:24

5

var singleView = regionManager.Regions["MyRegion"].ActiveViews.FirstOrDefault();

This is not correct, as it will just bring whatever view that got activated first. not the currently active/visible view.

Can't find a direct solution though, that doesn't involve custom implementation on View or ViewModel.

edited Dec 05 '11 at 03:24

competent_tech

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answered Dec 05 '11 at 03:18

Ahmed

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Interesting !! , but at the time it was what i needed. can you give more details ? – Ehsan Zargar Ershadi Dec 06 '11 at 21:36

score 2 · Answer 3 · answered Jun 05 '18 at 16:26

Well, you could use the NavigationService Journal. It takes record of all the navigation that takes place in your application. So, you can get the name of the view like this:

string name = mRegionManager.Regions[RegionNames.MainRegionStatic].NavigationService.Journal.CurrentEntry.Uri;

Then you can get the view like this:

mRegionManager.Regions[RegionNames.MainRegionStatic].GetView(name);

Sweet Right? :)

score 0 · Answer 4 · answered Dec 27 '21 at 22:34

Using Xamarin.Forms & Prism, this works well for me. Change the regionName, change the View Model base to yours.

public VisualElement GetCurrentRegionView()
{
    var regionName = "MenuPageRegion";
    var region = RegionManager.Regions[regionName];
    var uri = region.NavigationService.Journal.CurrentEntry.Uri.OriginalString;
    foreach (var view in region.ActiveViews)
    {
        var name = view.GetType().FullName;
        if (name.EndsWith(uri))
            return view;
    }
    return null;
}

public CommonViewModelBase GetCurrentRegionViewModel()
{
    var view = GetCurrentRegionView();
    if (view != null)
    {
        var binding = view.BindingContext;
        if (binding is CommonViewModelBase model)
            return model;
    }
    return null;
}

How to get the current active view in a region using PRISM?

4 Answers4