In MvvmCross you can navigate between view-model's as described in the Wiki:
https://github.com/MvvmCross/MvvmCross/wiki/ViewModel--to-ViewModel-navigation
It's good however to use a simple type-safety mechanism.
Suppose we have a ProductViewModel which expects two arguments for initialization:
public class ProductViewModel : MvxViewModel { public void Init(int productId, int clientId) { .... } }
ShowViewModel<ProductViewModel>(new { productId = pid, clientId = cid });
we can write:
NavigationHelper.ShowProduct(pid, cid);
where NavigationHelper is a simple utility class:
using Cirrious.CrossCore;
using Cirrious.MvvmCross.ViewModels; using Cirrious.MvvmCross.Views; using MyApp.Core.ViewModels; using Cirrious.MvvmCross.Platform; namespace MyApp.Core.Common { public static class NavigationHelper { public static void ShowProduct(int productId, int clientId) { ShowViewModel<ProductViewModel>(new { productId = productId, clientId = clientId }); } static void ShowViewModel<T>(object parameter) where T : IMvxViewModel { var viewDispatcher = Mvx.Resolve<IMvxViewDispatcher>(); var request = MvxViewModelRequest.GetDefaultRequest(typeof(T)); request.ParameterValues = ((object)parameter).ToSimplePropertyDictionary(); viewDispatcher.ShowViewModel(request); } } }
using Cirrious.MvvmCross.Platform; namespace statement is important because it contains the ToSimplePropertyDictionary() extension method implemented by MvvmCross.
Furthermore, instead of using the NavigationHelper class, we can move the ShowViewModel method to a ViewModelBase class:
public class ViewModelBase : MvxViewModel { protected static void ShowViewModel<T>(dynamic parameter) where T : IMvxViewModel { var viewDispatcher = Mvx.Resolve<IMvxViewDispatcher>(); var request = MvxViewModelRequest.GetDefaultRequest(typeof(T)); request.ParameterValues = ((object)parameter).ToSimplePropertyDictionary(); viewDispatcher.ShowViewModel(request); } } public class ProductViewModel : ViewModelBase { public static Show(int productId, int clientId) { ShowViewModel<ProductViewModel>(new { productId = productId, clientId = clientId }); } public void Init(int productId, int clientId) { ... } }
ProductViewModel.Show(pid, cid);
Having the Show method near the Init method in the ViewModel class, makes it a bit more easier to maintain the parameters.
