I just moved a project from Prism to MvvmLight and it seems to work faster (very subjective). Both Prism and MvvmLight have Mediator realisation (IEventAggregator in Prism, IMessenger in MvvmLight). But IMessenger has more abilities (for instance, sending messages with tokens) compared to IEventAggregator and is much more convenient to use (see next item). MvvmLight … Read more
Jesse Liberty of Microsoft has a great concrete walk through on how to make use of the messaging within MVVM Light. The premise is to create a class which will act as your message type, subscribe, then publish. public class GoToPageMessage { public string PageName { get; set; } } This will essentially send the … Read more
You have to add a PropertyChanged listener to each item (which must implement INotifyPropertyChanged) to get notification about editing objects in a observable list. public ObservableCollection<Item> Names { get; set; } public List<Item> ModifiedItems { get; set; } public ViewModel() { this.ModifiedItems = new List<Item>(); this.Names = new ObservableCollection<Item>(); this.Names.CollectionChanged += this.OnCollectionChanged; } void OnCollectionChanged(object … Read more
First, lets look at what ViewModelLocator does and why we use it: ViewModelLocator is declared as an object on our App.xaml page and is an application singleton. We’re going to have one, and only one of them available to the application when it runs. ViewModelLocator is the source for all our ViewModels in MVVM Light. … Read more
If you want to build an MVVM application (which you probably do for various advantages), then you want an MVVM framework. I would recommend Caliburn.Micro, as it is straightforward to implement following the examples on the Caliburn.Micro documentation page. It also has a very compelling convention over configuration mechanism, and uses an Actions system to … Read more
Suppose you use .NetFramework4: First add namespace: xmlns:cmd=”clr-namespace:GalaSoft.MvvmLight.Command;assembly=GalaSoft.MvvmLight.Platform” Syntax for the Loaded event. <i:Interaction.Triggers> <i:EventTrigger EventName=”Loaded”> <cmd:EventToCommand Command=”{Binding Mode=OneWay, Path=LoadedCommand}” PassEventArgsToCommand=”True” /> </i:EventTrigger> </i:Interaction.Triggers>
If you need modularity, you’d want to look at Prism. Prism has some elements that can help you with MVVM (DelegateCommand and CompositeCommand, for example), but I think it’s more complete with another MVVM framework. There was a question a few days ago about how to model Prism. Check that out for a detailed explanation … Read more
The ViewModelLocator class helps keep a centralized store for your viewmodels. You can use this class to help manage new versions and clean up old ones. I always reference my viewmodel from view via the locator, so I always have code I can run to manage these things. You could try that. As well, I … Read more
I believe this will work: _projmenuItem_Edit = new RelayCommand<object>((txt)=>ProjEditNode(txt)); — EDIT — You’ll need to define your RelayCommand with the type as well: e.g. public RelayCommand<string> myCommand { get; private set; } myCommand = new RelayCommand<string>((s) => Test(s)); private void Test(string s) { throw new NotImplementedException(); }
Passing a message from ViewModel1 to View1 means to use the messaging capabilities in the MVVM Light Toolkit. For example, your ViewModel1 could have a command called ShowView2Command, then it would send a message to display the view. public class ViewModel1 : ViewModelBase { public RelayCommand ShowView2Command { private set; get; } public ViewModel1() : … Read more